Time For a Rebuild?
09-09-09, 03:29 PM
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Time For a Rebuild?
Several weeks ago I posted a thread about my 85 GS 12A not idling when warmed up. I asked about jumpering out the thermo switch that controls the choke magnet so that I could keep it running for the time being until I had the money to get it in and checked out.
Okay, I got the money together and took it into the area Mazda dealer. They have a tech. there that has been working on Mazdas and rotary engines for 37 years. As a recap the car is completely stock, and I am the original owner and it has 69,000 miles on it, had not been worked on for a couple years and had been running fine (I thought) until it wouldn't idle when warm. I had run out the gas with stabil in it from the winter storage and refilled it and added in a bottle of carb. cleaner just before all this happened. I searched the posts and it semmed that the first thing to check was for a vacum leak, particularly the vacum line for the anti afterburn valve.
That's the first thing that they did, checked for a vacum leak and didn't find one. They did find that the coasting valve was not activating, the ignition wires wer old and brittle and the cap and rotor were pretty burned. They also said that the carburetor was flooding, propably worn out needles/seats.
I could understand this since these were all original parts.
After they fixed all of this and they put it back together again it starts fine warms up and does idle once its warmed up and the choke releases. So far so good.
It doesn't idle smooth as glass but it it pretty darn smooth. However when you rev it up it will, for lack of a better term, ping a bit. Not every time but it does do it. Mind you this was not under load just in nuetral. I watched it in the shop while the air cleaner was off and he had the associated lines to it plugged with screws etc. Could there have been a slight vacum leak caused by these screws/plugs?
Now they've had it for a couple weeks and thought that there might be some carbon built up so the did the old ATF down the carb. trick to it and no change. At this point they also checked timing and it was right on. They supposedly called the Mazda techs out it CA and they seem to think that a apex grove in the rotor has widened and that the apex seal is moving around in the grove. They tell me that the only way to tell is to tear the engine down.
Now I'm a bit confused. They checked the compression with there special Mazda rotary compression tester and he told me that it is good at 6.5 and the variation is well under the 1.5 listed in the FSM.
If there is a problem with the apex seals wouldn't the compression be off? Also why would the rotor apex grove wear and not the apex seal. Isn't the rotor harder then the seal?
Should I just try running the gas that's in there now out and try different gas? Could it be the carb. cleaner that I added causing the problem? If I fill it with new gas should I try adding some Sea Foam to the gas incase it is carbo buildup?
Your thoughts will be greatly appreciated!
Okay, I got the money together and took it into the area Mazda dealer. They have a tech. there that has been working on Mazdas and rotary engines for 37 years. As a recap the car is completely stock, and I am the original owner and it has 69,000 miles on it, had not been worked on for a couple years and had been running fine (I thought) until it wouldn't idle when warm. I had run out the gas with stabil in it from the winter storage and refilled it and added in a bottle of carb. cleaner just before all this happened. I searched the posts and it semmed that the first thing to check was for a vacum leak, particularly the vacum line for the anti afterburn valve.
That's the first thing that they did, checked for a vacum leak and didn't find one. They did find that the coasting valve was not activating, the ignition wires wer old and brittle and the cap and rotor were pretty burned. They also said that the carburetor was flooding, propably worn out needles/seats.
I could understand this since these were all original parts.
After they fixed all of this and they put it back together again it starts fine warms up and does idle once its warmed up and the choke releases. So far so good.
It doesn't idle smooth as glass but it it pretty darn smooth. However when you rev it up it will, for lack of a better term, ping a bit. Not every time but it does do it. Mind you this was not under load just in nuetral. I watched it in the shop while the air cleaner was off and he had the associated lines to it plugged with screws etc. Could there have been a slight vacum leak caused by these screws/plugs?
Now they've had it for a couple weeks and thought that there might be some carbon built up so the did the old ATF down the carb. trick to it and no change. At this point they also checked timing and it was right on. They supposedly called the Mazda techs out it CA and they seem to think that a apex grove in the rotor has widened and that the apex seal is moving around in the grove. They tell me that the only way to tell is to tear the engine down.
Now I'm a bit confused. They checked the compression with there special Mazda rotary compression tester and he told me that it is good at 6.5 and the variation is well under the 1.5 listed in the FSM.
If there is a problem with the apex seals wouldn't the compression be off? Also why would the rotor apex grove wear and not the apex seal. Isn't the rotor harder then the seal?
Should I just try running the gas that's in there now out and try different gas? Could it be the carb. cleaner that I added causing the problem? If I fill it with new gas should I try adding some Sea Foam to the gas incase it is carbo buildup?
Your thoughts will be greatly appreciated!
09-09-09, 05:16 PM
#3
Stu: Mazda tester read in kg/cm^2 (instead of psi).
The minimum reading per FSM is 6 kg/cm^2 with less than 1.5 kg/cm^2 difference between max and min reading. However, we need the cranking RPM during the test. The limit of 6 is based on a cranking speed of 240-250 RPM. If you were only spinning 200 RPM, the limit drops to just over 5. If you are spinning over close to 300 RPM, the limit is more like 6.8. So, your readings are either just fine or no good depending on cranking speed.
I doubt it is a compression issue or worn apex seal grooves. You mileage is low, so it should not be a wear issue. However, compression could be a little low due to carbon buildup causing seals to stick a bit.
The ping sounds like timing issue. It is possible that the plug wires are crossed and/or timing off of the wrong wire. I'll think more about it and see what I can come up with. I am sure there are others that will have some ideas as well.
The minimum reading per FSM is 6 kg/cm^2 with less than 1.5 kg/cm^2 difference between max and min reading. However, we need the cranking RPM during the test. The limit of 6 is based on a cranking speed of 240-250 RPM. If you were only spinning 200 RPM, the limit drops to just over 5. If you are spinning over close to 300 RPM, the limit is more like 6.8. So, your readings are either just fine or no good depending on cranking speed.
I doubt it is a compression issue or worn apex seal grooves. You mileage is low, so it should not be a wear issue. However, compression could be a little low due to carbon buildup causing seals to stick a bit.
The ping sounds like timing issue. It is possible that the plug wires are crossed and/or timing off of the wrong wire. I'll think more about it and see what I can come up with. I am sure there are others that will have some ideas as well.
09-10-09, 10:40 AM
#4
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Yeah, your motor is fine. Mine went to 213,000 miles before I had serious issues.
Make sure the idiots put the plug wires on correctly. Then check the timing yourself to make sure it is accurate. Make sure they didn't swap the coils or ignitors around on accident, so you'd end up with the leading firing the trailing, etc. You can do this by unplugging one of the ignitors, then testing to make sure that side no longer gets spark.
Run a can of Seafoam through the gas tank.
Make sure the idiots put the plug wires on correctly. Then check the timing yourself to make sure it is accurate. Make sure they didn't swap the coils or ignitors around on accident, so you'd end up with the leading firing the trailing, etc. You can do this by unplugging one of the ignitors, then testing to make sure that side no longer gets spark.
Run a can of Seafoam through the gas tank.
09-10-09, 11:11 AM
#5
Oh, and to answer the other question: the apex seals are FAR harder than the rotor - - stock cast-iron apex seals are specially hardened using an electron-beam process, and the rotors are actually fairly soft. Side, oil, and corner seals, bearings, and the rotor gear, are all hardened iron or steel. Ceramic seals are harder still.
The seals have to be extremely hard to resist frictional wear. The rotors are intentionally soft to avoid fracture, since they they don't actually "rub" on anything except the seals, which move only slightly in relation to the grooves.
The seals have to be extremely hard to resist frictional wear. The rotors are intentionally soft to avoid fracture, since they they don't actually "rub" on anything except the seals, which move only slightly in relation to the grooves.
09-10-09, 02:09 PM
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Thanks for the help guys. I asked the tech that worked on it about the wires maybe getting swapped around and I got a look like I was insulting his intelligence. I would check it myself it's easy enough to do but I can't find the routing for the wires between the distributor and the plugs in the FSM or the Haynes manuals. Can someone give me a clue?
09-10-09, 03:01 PM
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Thanks for the help guys. I asked the tech that worked on it about the wires maybe getting swapped around and I got a look like I was insulting his intelligence. I would check it myself it's easy enough to do but I can't find the routing for the wires between the distributor and the plugs in the FSM or the Haynes manuals. Can someone give me a clue?
if compression tests good, and the engine runs fine except for a little pinging, in my experience the engine is ok, but there is something else wrong.
i have had rotary engines ping on a few occasions, they all have been either too lean, or have had the timing too far advanced (reverse the plug wires and it sounds BAD like you threw a spoon in the blender, its obvious!).
the too lean part i have seen, one car had a weak fuel pump, it would ping up long uphills...
the other cars have all had vacuum leaks. one car had the air pump come apart, and the pieces jammed the air control valve, causing a HUGE vacuum leak that WAS NOT EXTERNAL.
other thing to look at is the mystery hose, the one that goes from the top rear of the intake/carb to the bottom rear. the hose is close to the exhaust and it'll split on the bottom, where you cannot SEE it. n201-13-756a...
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09-10-09, 03:30 PM
#8
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What type of spark plugs did they use? If they were Denso, then try NGK. I've had issues with Denso before and will never use them again.
My car ended up getting the leading and trailing ignition swapped around while I was doing some testing for the Transistor Trick a couple years back. It was like that for several months, and the only issue I had was that it was difficult to tune the timing to get rid of spark knock. I was really kicking myself when I finally found the issue. So, it doesn't always sound like a spoon in a blender.
My car ended up getting the leading and trailing ignition swapped around while I was doing some testing for the Transistor Trick a couple years back. It was like that for several months, and the only issue I had was that it was difficult to tune the timing to get rid of spark knock. I was really kicking myself when I finally found the issue. So, it doesn't always sound like a spoon in a blender.
09-10-09, 03:35 PM
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The timing was checked and found to be right on. The vacum was also checked and no leaks were found. Question, couldn't you hook a vacum gauge into one of the hoses and check to see if there is a vacum leak instead of just checking the hoses and hoping that you catch it? If so what should the vacum be and where should you hook into?
If reversing the plug wires would make it run terrible then that doesn't seem to be the problem. It seems to start, high idle pretty good cold and at 750rpm when warmed up.
That leaves the fuel pump to check out. Or, since he rebuilt the carb, that it's running lean.
The original problem that I took it in for is fixed, the not idling when warmed up.
Could it be something as simple as having gotten some bad gas and I just need to get rid of it and get some new? I noticed the ping when I was standing next to the engine with the air cleaner off. I haven't been able to drive the car to see how it actually feels as it's still at the dealer and he's pushing me to let him rebuild the engine.
Since the carb was rebuilt what could have happened that it is now running lean. I thought that the mixture adjusting screw is only for the idle circuit and it pings on rapid acceleration.
If reversing the plug wires would make it run terrible then that doesn't seem to be the problem. It seems to start, high idle pretty good cold and at 750rpm when warmed up.
That leaves the fuel pump to check out. Or, since he rebuilt the carb, that it's running lean.
The original problem that I took it in for is fixed, the not idling when warmed up.
Could it be something as simple as having gotten some bad gas and I just need to get rid of it and get some new? I noticed the ping when I was standing next to the engine with the air cleaner off. I haven't been able to drive the car to see how it actually feels as it's still at the dealer and he's pushing me to let him rebuild the engine.
Since the carb was rebuilt what could have happened that it is now running lean. I thought that the mixture adjusting screw is only for the idle circuit and it pings on rapid acceleration.
09-10-09, 03:37 PM
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I'm not sure about the plugs as they weren't changed at this time. They were changed about 4,000 miles ago with Mazda plugs by the dealer when I had them do the 60,000 mile scheduled maintenance.
09-10-09, 03:39 PM
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What type of spark plugs did they use? If they were Denso, then try NGK. I've had issues with Denso before and will never use them again.
My car ended up getting the leading and trailing ignition swapped around while I was doing some testing for the Transistor Trick a couple years back. It was like that for several months, and the only issue I had was that it was difficult to tune the timing to get rid of spark knock. I was really kicking myself when I finally found the issue. So, it doesn't always sound like a spoon in a blender.
My car ended up getting the leading and trailing ignition swapped around while I was doing some testing for the Transistor Trick a couple years back. It was like that for several months, and the only issue I had was that it was difficult to tune the timing to get rid of spark knock. I was really kicking myself when I finally found the issue. So, it doesn't always sound like a spoon in a blender.
1. swap T1 and T2, spoon in blender, power drops to like 2hp, spoon in blender noises, BAD!
2. swap the L and trailing coil wires. this fires trailing first, at light loads it might actually run better... easy to check too. leading coil is in the REAR boot on it is BLACK, trailing is in the FRONT (never understood this, one of the few counter intuative things on the car) the boots on the coil are BLUE.
09-10-09, 07:00 PM
#13
With that low of mileage on the engine, I'd say take it home and drive it. Run a can of Seafoam through the tank and drive it hard for a good carbon cleaning. If you/they suspect it's running lean, then install a wideband O2 bung in the exhaust and take some afr readings. Chances are are only one rotor is running lean and it's hard to figure which rotor is running lean with the stock exhaust.
From your description, I take it you have very little mechanical experience working on your 7. Unfortunately that puts you at the mercy of the dealer. At this point in time I see absoluely no need for a rebuild. If you do decide to go that route, find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion. mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion.
From your description, I take it you have very little mechanical experience working on your 7. Unfortunately that puts you at the mercy of the dealer. At this point in time I see absoluely no need for a rebuild. If you do decide to go that route, find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion. mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion.
09-11-09, 01:59 AM
#14
Vacuum leaks in the hoses can be diagnosed. First, unplug and cap all hoses. Hook vac gauge up and see what you have at an idle. No one at a time, connect the remaining hoses. If you have a bad hose your idle vac will drop and you will have your culprit. I am guessing you have a timing issue as well, learn to set it yourself, the money saved will pay for the timing light needed to do the job. There is a huge reward in finding the problem and solving it yourself. I had a reliable 12a 83fb with over 260,000 km on it (160,000 miles) and it ran like a champ.
09-11-09, 11:00 AM
#15
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With that low of mileage on the engine, I'd say take it home and drive it. Run a can of Seafoam through the tank and drive it hard for a good carbon cleaning. If you/they suspect it's running lean, then install a wideband O2 bung in the exhaust and take some afr readings. Chances are are only one rotor is running lean and it's hard to figure which rotor is running lean with the stock exhaust.
From your description, I take it you have very little mechanical experience working on your 7. Unfortunately that puts you at the mercy of the dealer. At this point in time I see absoluely no need for a rebuild. If you do decide to go that route, find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion. mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion.
From your description, I take it you have very little mechanical experience working on your 7. Unfortunately that puts you at the mercy of the dealer. At this point in time I see absoluely no need for a rebuild. If you do decide to go that route, find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low find somone local that specializes in rotarys. A second opinion is definitely needed before commiting to the expense of a dealer rebuild. You might ask the dealer's rotary mechanic when was the last time they rebuilt a 1st gen rotary, or do the just simply order rebuilt cores. With the low mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion. mileage on your's, internals should be in excellant condition.
Another thing to consider before a rebuild is replacing all of the vacuum hoses. It may be the case that several lines have very small leaks which can add up to a large one. Tracing down pinhole vacuum leaks can be near impossible at times. I knew I had a vacuum leak on my FC but couldn't find it. Once I tore it apart I finally found that I had 3 very small ones that added up to a large enough leak to cause problems.
I suggest you post in your regiopnal forum and find a local builder who can take a look at your's and give you a second opinion.
09-11-09, 01:37 PM
#16
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Perhaps he's been drinking. My posts can come off a little silly after a good number of beers.
Have you replaced your fuel filter yet? A seriously clogged filter could cause fuel supply issues, possibly causing the car to run lean, which then causes the pinging.
You'll know when it's time for a rebuild, because the car will have absolutely no power and will sound like a lawn mower. This can happen at any time and seemingly for no reason. Ask me how I know.
Have you replaced your fuel filter yet? A seriously clogged filter could cause fuel supply issues, possibly causing the car to run lean, which then causes the pinging.
You'll know when it's time for a rebuild, because the car will have absolutely no power and will sound like a lawn mower. This can happen at any time and seemingly for no reason. Ask me how I know.
09-11-09, 01:57 PM
#17
Sorry, don't drink. Not trying to step on anyones toes, just covering all the bases. As we all know, sometimes posters need to hear the same thing from more than one experienced member, but this guy has owned his since it was new so who really has more experiece? 
I also added more info in case you skimmed my post.
I also added more info in case you skimmed my post.
09-11-09, 02:32 PM
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Well I picked it up from the dealer today and it runs worse then when I took it in. When I took it in it just wouldn't idle when warm. Otherwise it seemed okay. The dealer replaced the distributor cap, rotor, wire set, plugs, fuel filter and coasting valve (it was not activating durring decel). He rebuilt the carb., said it was flooding. He also ran a compresion test and found that it was within spec. Said that he couldn't find a vacum leak but that the vacum from the manifold was only 10 (not sure if its inches of vacum or psi) vac when it should be at least 18. Sounds to me like a vacum leak but he insists that it is internal to the engine. And needs to be torn down.
What I can tell you is that when driving it idles fast now at 1000rpm and will die when coming down to an idle for a stop with the air conditioning on. Also it was no power at all when you get it up to about 3000 rpm and starts the pinging.
Isn't this great, take it in, pay em $1,258 and it runs worse then when I took it in!
What I can tell you is that when driving it idles fast now at 1000rpm and will die when coming down to an idle for a stop with the air conditioning on. Also it was no power at all when you get it up to about 3000 rpm and starts the pinging.
Isn't this great, take it in, pay em $1,258 and it runs worse then when I took it in!
09-11-09, 03:01 PM
#20
Sorry to hear about that. This is why we tend to do things ourselves around here
1. way cheaper
2. learn something
3. DIYers on here tend to do better than the mechanics (even the Master ones) when it comes to these cars
There are very few shops out there that really know what they are doing when it comes to these cars. Really only a handful in the whole country.
We'll try to figure this out with you. It is a good learning experience for you too. Each thing you fix is another thing to put into your bag of tricks. Before you know it, you'll be able to rebuild that engine yourself (when the time does come).
I would check the timing yourself. Go over the plug wires and make sure everything is going to the right spot. Check over the carb and vacuum lines and look for leaks or anything disconnected. I really doubt it is internal (sounds like he is trying to make some $$$ off you). It is probably a vacuum leak. Also check spark on all plugs with the car warmed up..maybe leading is cutting out with the warm engine causing the poor idle and poor vac.
Also, post in the regional section on the forum too. You might find some experienced rotorheads in your area that will give you a hand. If you were near me, I would come over to help. 1st gen guys are generally really good about helping each other out.
1. way cheaper
2. learn something
3. DIYers on here tend to do better than the mechanics (even the Master ones) when it comes to these cars
There are very few shops out there that really know what they are doing when it comes to these cars. Really only a handful in the whole country.
We'll try to figure this out with you. It is a good learning experience for you too. Each thing you fix is another thing to put into your bag of tricks. Before you know it, you'll be able to rebuild that engine yourself (when the time does come).
I would check the timing yourself. Go over the plug wires and make sure everything is going to the right spot. Check over the carb and vacuum lines and look for leaks or anything disconnected. I really doubt it is internal (sounds like he is trying to make some $$$ off you). It is probably a vacuum leak. Also check spark on all plugs with the car warmed up..maybe leading is cutting out with the warm engine causing the poor idle and poor vac.
Also, post in the regional section on the forum too. You might find some experienced rotorheads in your area that will give you a hand. If you were near me, I would come over to help. 1st gen guys are generally really good about helping each other out.
09-11-09, 03:21 PM
#21
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Sorry to hear about that. This is why we tend to do things ourselves around here
1. way cheaper
2. learn something
3. DIYers on here tend to do better than the mechanics (even the Master ones) when it comes to these cars
Also, post in the regional section on the forum too. You might find some experienced rotorheads in your area that will give you a hand. If you were near me, I would come over to help. 1st gen guys are generally really good about helping each other out.
1. way cheaper
2. learn something
3. DIYers on here tend to do better than the mechanics (even the Master ones) when it comes to these cars
Also, post in the regional section on the forum too. You might find some experienced rotorheads in your area that will give you a hand. If you were near me, I would come over to help. 1st gen guys are generally really good about helping each other out.
2. fer shur!
3. that would not be true if the techs who worked on these cars new weren't retired... a real good tech is smart enough to get a job that pays more too
09-11-09, 03:28 PM
#22
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An internal vacuum leak. Now why didn't I think of that? Freaking idiots.....
I'll bet you either have a bad vacuum leak, or they did a **** job of rebuilding the carb. I would check the fuel jets and make sure they aren't clogged. Search for "jets toothpick" and you should find a writeup on a simple method to remove and replace the jets, without tearing the carb down again.
Orion, a fuel filter causing a lean condition was a good thought, but he's getting pinging while revving in nuetral. The problem is either in the ignition, or an internal carb blockage...
I'll bet you either have a bad vacuum leak, or they did a **** job of rebuilding the carb. I would check the fuel jets and make sure they aren't clogged. Search for "jets toothpick" and you should find a writeup on a simple method to remove and replace the jets, without tearing the carb down again.
Orion, a fuel filter causing a lean condition was a good thought, but he's getting pinging while revving in nuetral. The problem is either in the ignition, or an internal carb blockage...
09-11-09, 04:28 PM
#23
Poor vac can also be caused by something else (besides vac leaks) causing the engine to run poor. Like if your ignition was hosed or the carb jets were clogged or something. For instance, it is common to use vacuum as a measure to dial in your idle mixture. Once the vacuum is the stongest, you have the optimum mixture.
There is also a big hose on the passenger side which tends to crack on the bottom (where it can't be seen). This can cause a big vac leak and is hard to track down unless you know to look for it. I'll dig up the thread about it for you.
The sypmtoms you have (pinging, poor vacuum, low power down low, not a strong idle) points to one of the following:
- timing is way off
- vacuum leak somewhere (if not at hoses, it can be at the intake gasket)
- carb messed up (can't trust the rebuild either)
I would start with timing as it is easy to do. A timing light is a handy tool if you don't already have one. This will confirm that you are getting spark as well as the spark is occuring at the right time. Check the plug wires while you are at it. Check that the wires are fully seated and probably pull the spark plugs and note condition. Also, let us know what kind of plugs are in it (take a pic would be good).
Then hunt for vac leaks or check over the carb if the timing is good. Just check things off the list until you find the problem. Good luck.
There is also a big hose on the passenger side which tends to crack on the bottom (where it can't be seen). This can cause a big vac leak and is hard to track down unless you know to look for it. I'll dig up the thread about it for you.
The sypmtoms you have (pinging, poor vacuum, low power down low, not a strong idle) points to one of the following:
- timing is way off
- vacuum leak somewhere (if not at hoses, it can be at the intake gasket)
- carb messed up (can't trust the rebuild either)
I would start with timing as it is easy to do. A timing light is a handy tool if you don't already have one. This will confirm that you are getting spark as well as the spark is occuring at the right time. Check the plug wires while you are at it. Check that the wires are fully seated and probably pull the spark plugs and note condition. Also, let us know what kind of plugs are in it (take a pic would be good).
Then hunt for vac leaks or check over the carb if the timing is good. Just check things off the list until you find the problem. Good luck.
09-11-09, 08:11 PM
#25
Didin't even notice that. I was having trouble opening the advanced page to check spelling and composition. Apparently made a mistake with the cut and paste. It's not the fumes from the widebody, that needs to run more once I finish puitting it back together again, then put it up for sale.