Tdc....
05-31-08, 05:06 PM
#1
Tdc....
I pretty damn sure this isnt normal. Ive stabbed my CAS 3 times now and when i check it with the timing light its always at advance. A LOT advance. then i pull it off and the mark on the CAS says its dead on
. so i went ahead and stabbed it so itll be a tooth off, and it it felt like ****.
so i stabbed it again. now the best way for the car to run is if i put the CAS as retarded as possible, only then is it able to get as close as it can to the TDC mark on the pulley. but its still way too advance.
any ideas??
. so i went ahead and stabbed it so itll be a tooth off, and it it felt like ****.so i stabbed it again. now the best way for the car to run is if i put the CAS as retarded as possible, only then is it able to get as close as it can to the TDC mark on the pulley. but its still way too advance.
any ideas??
05-31-08, 07:06 PM
#3
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1. The engine MUST be HOT when checking the timing with a timing light.
2. The rpms MUST be well below 1000 rpm when checking the timing with a timing light.
3. If the two items above are met, then it seems you either don't know to, or did not write about, how if you see the timing off the mark, that you rotate the CAS til the marks align with the timing light (while the timing light is on and the engine is idling).
4. The timing marks on the pulley are MINUS 5* and MINUS 20* or 5* ATDC and 20*ATDC. Whichever way you want to call it. Neither is TDC.
5. Items 1 and 2 are required because the ECU will alter the timing if the rpms are over 1100 rpm and/or if the ECU sees a cold temp from the water thermo sensor. See the FSM.
2. The rpms MUST be well below 1000 rpm when checking the timing with a timing light.
3. If the two items above are met, then it seems you either don't know to, or did not write about, how if you see the timing off the mark, that you rotate the CAS til the marks align with the timing light (while the timing light is on and the engine is idling).
4. The timing marks on the pulley are MINUS 5* and MINUS 20* or 5* ATDC and 20*ATDC. Whichever way you want to call it. Neither is TDC.
5. Items 1 and 2 are required because the ECU will alter the timing if the rpms are over 1100 rpm and/or if the ECU sees a cold temp from the water thermo sensor. See the FSM.
06-01-08, 06:40 PM
#4
no. all the pulleys are the ones that came with the motor.
Number 3 " how if you see the timing off the mark"<<<<you lost me here. Number 4, i used TDC becasue is known this way. i really didnt find the need to post it the way Mazda says. Number 5, i own the orange book. Or do i have to put down the name for you? You just gave me a bunch of useless information....
look this is simple man.
The car is off (and warm), i get a 19mm and a wrench, i turn the bolt clockwise (turning the engine D...D...DEh) till the yellow mark is align with the pin. i unplug the CAS, unscrew the cap, grab a 10 mm and unbolt the CAS. Once i pull it off, i take a look at the mark on the CAS. Now every time i pull it off its dead on. Check this part out because this is where it gets good: When i stab the CAS back in (making sure that its not jumping a tooth) and bolt it down some, pug it in and connect the timing light to the battery (you know...so the timing light works) and the other one to the number one leading. start the car and go back under my hood. Point the timing gun to the pulley and press the trigger...
ok so the engine is warm and my idle is a 900....and this is the weird part. The light tells me that im way off and i need to retard some to get to 5 degress ATDC.
Meaning that both the marks...leading and trailing are behind the pointer. So i retard the CAS and it gets close to 5*ATDC.
The car runs better the closer it gets to 5* ATDC but i cant reach the mark because I cant turn the CAS any more. After I turn off the engine, I align the mark again and go to pull off the CAS. I check it to see if the line is inline with the circle on the CAS. Amazingly it is so i get all confused. So i stabbed it again with the marks on the CAS off a tooth. The car ran like **** so i pull it off and did it the right way again.
The car runs fine but my question here is why isnt on time? The CAS itself looks lilke my engine is retarded, but its way at advance.
any ideas?
1. The engine MUST be HOT when checking the timing with a timing light.
2. The rpms MUST be well below 1000 rpm when checking the timing with a timing light.
3. If the two items above are met, then it seems you either don't know to, or did not write about, how if you see the timing off the mark, that you rotate the CAS til the marks align with the timing light (while the timing light is on and the engine is idling).
4. The timing marks on the pulley are MINUS 5* and MINUS 20* or 5* ATDC and 20*ATDC. Whichever way you want to call it. Neither is TDC.
5. Items 1 and 2 are required because the ECU will alter the timing if the rpms are over 1100 rpm and/or if the ECU sees a cold temp from the water thermo sensor. See the FSM.
2. The rpms MUST be well below 1000 rpm when checking the timing with a timing light.
3. If the two items above are met, then it seems you either don't know to, or did not write about, how if you see the timing off the mark, that you rotate the CAS til the marks align with the timing light (while the timing light is on and the engine is idling).
4. The timing marks on the pulley are MINUS 5* and MINUS 20* or 5* ATDC and 20*ATDC. Whichever way you want to call it. Neither is TDC.
5. Items 1 and 2 are required because the ECU will alter the timing if the rpms are over 1100 rpm and/or if the ECU sees a cold temp from the water thermo sensor. See the FSM.
look this is simple man.
The car is off (and warm), i get a 19mm and a wrench, i turn the bolt clockwise (turning the engine D...D...DEh) till the yellow mark is align with the pin. i unplug the CAS, unscrew the cap, grab a 10 mm and unbolt the CAS. Once i pull it off, i take a look at the mark on the CAS. Now every time i pull it off its dead on. Check this part out because this is where it gets good: When i stab the CAS back in (making sure that its not jumping a tooth) and bolt it down some, pug it in and connect the timing light to the battery (you know...so the timing light works) and the other one to the number one leading. start the car and go back under my hood. Point the timing gun to the pulley and press the trigger...
ok so the engine is warm and my idle is a 900....and this is the weird part. The light tells me that im way off and i need to retard some to get to 5 degress ATDC.
Meaning that both the marks...leading and trailing are behind the pointer. So i retard the CAS and it gets close to 5*ATDC.
The car runs better the closer it gets to 5* ATDC but i cant reach the mark because I cant turn the CAS any more. After I turn off the engine, I align the mark again and go to pull off the CAS. I check it to see if the line is inline with the circle on the CAS. Amazingly it is so i get all confused. So i stabbed it again with the marks on the CAS off a tooth. The car ran like **** so i pull it off and did it the right way again.
The car runs fine but my question here is why isnt on time? The CAS itself looks lilke my engine is retarded, but its way at advance.
any ideas?
Last edited by Aaron Cake; 06-02-08 at 10:17 AM.
06-01-08, 10:11 PM
#5
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Has this engine been rebuilt?
I put the part about the engine having to be hot and below 1100 rpm because the ECU alters the timing if above 1100 rpm and also if the engine is cold.
Since you tried to restab the cas several times and it does not work out for you, and assuming you did it right, there could be a mechanical reason for your problem.
IF the CAS DRIVE gear is not installed right, your problem can happen. The DRIVE gear is supposed to be installed with its champer towards the front side housing. IF it is installed just the opposite, you end up with the problem you have right now.
I've made that mistake in the past with the drive gear. Rather than pull the front cover off and go thru that bull, I just elongated the slot in the CAS. The slot where the stud/nut holds the CAS in place. That gave me enough room to turn the CAS enough to align the marks on the pulley with the fixed pin. Beat the heck out of pulling the front cover.
A couple of other threads this year came to the same conclusion about the CAS Drive GEAR on the eccentric shaft.
Usually if you take the flat black cover off the top of the CAS, then align the marks on the bottom of the CAS, then look again in the top of the CAS at the two *pointers* on top of the shaft, you'll see that they cut across the corner of the two black coils on the fixed part of the cas. THEN when you stab the CAS, the shaft will turn a bit, but you can turn the CAS body til the two fixed pointers match where they were in prior to stabing the CAS.
That works well on a engine that has been put together right with the CAS drive gear installed right. A person can get within 5* of where it should be doing that without a timing light. Not saying a timing light shouldn't be used, just saying it the method just mentioned is used you can get darn close.
If that engine has never been rebuilt, then the above should not apply. The part about the CAS drive gear that is.
The drive gear is shown in this thread: https://www.rx7club.com/attachment.p...3&d=1204768153
I put the part about the engine having to be hot and below 1100 rpm because the ECU alters the timing if above 1100 rpm and also if the engine is cold.
Since you tried to restab the cas several times and it does not work out for you, and assuming you did it right, there could be a mechanical reason for your problem.
IF the CAS DRIVE gear is not installed right, your problem can happen. The DRIVE gear is supposed to be installed with its champer towards the front side housing. IF it is installed just the opposite, you end up with the problem you have right now.
I've made that mistake in the past with the drive gear. Rather than pull the front cover off and go thru that bull, I just elongated the slot in the CAS. The slot where the stud/nut holds the CAS in place. That gave me enough room to turn the CAS enough to align the marks on the pulley with the fixed pin. Beat the heck out of pulling the front cover.
A couple of other threads this year came to the same conclusion about the CAS Drive GEAR on the eccentric shaft.
Usually if you take the flat black cover off the top of the CAS, then align the marks on the bottom of the CAS, then look again in the top of the CAS at the two *pointers* on top of the shaft, you'll see that they cut across the corner of the two black coils on the fixed part of the cas. THEN when you stab the CAS, the shaft will turn a bit, but you can turn the CAS body til the two fixed pointers match where they were in prior to stabing the CAS.
That works well on a engine that has been put together right with the CAS drive gear installed right. A person can get within 5* of where it should be doing that without a timing light. Not saying a timing light shouldn't be used, just saying it the method just mentioned is used you can get darn close.
If that engine has never been rebuilt, then the above should not apply. The part about the CAS drive gear that is.
The drive gear is shown in this thread: https://www.rx7club.com/attachment.p...3&d=1204768153
Last edited by Aaron Cake; 06-02-08 at 10:20 AM.
06-01-08, 10:51 PM
#6
mechanical reason sounds about right. i got this motor from osaka ( jesus christ ). and when i got it it came with a type s bov and an os giken clutch. now the bolts on the engine where numbered. so im assuming this engine was rebuilt.
so you elongated the slot where the stud/ nut holds the CAS in place. and your car is still running at this point with it like this right. Pretty good idea, does your CAS look as if were to be all the way retarded?
so you elongated the slot where the stud/ nut holds the CAS in place. and your car is still running at this point with it like this right. Pretty good idea, does your CAS look as if were to be all the way retarded?
06-01-08, 11:26 PM
#7
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That happened on a 1986 non turbo car about five years ago or more. Runs fine. I've been looking for the thread where someone else has/had this problem and can't find it. When I read his thread It struck a cord, especially when he went and turned the cas drive gear the right way and after that he had no problems at all.
It's also possible that the front pulley came off another engine and that MIGHT be the problem. I've read several places where they CLAIM that the front pulley and hub are not the same for every engine. Therefore if you put a pulley and hub off one engine on the other engine, the timing marks won't be the same and the timing will be off. I've a real problem with that. It's a production engine and every engine has the same timing.
There is a way to *FIX* that problem if true (pulley off another engine). You get/buy a Racing Beat front pulley/hub. THAT Pulley/hub is a one part outfit. No bolts to hold the pulley to the hub. Plus it has four timing marks. I forget what they are. One is TDC. HIGGEY claims this is the way to go if you suspect the wrong pulley/hub is on the engine. He says what he does is use the RB pulley/hub to remark the old used pulleys he's collected.
It sounds like your problem might be the drive gear put on backwards because you say the engine sounds better the closer you get to the marks.
Yes. I took a christmas tree rotary file to the slot so I could turn the CAS more towards the retard position i.e. CCW. Car runs like a top and passes emissions testing each year.
This problem came up just after I rebuilt the engine. It drove me up a tree because I'd never had this problem before on a rebuild and I KNEW I had used the same pulley on the rebuild that it came with. Common sense told me I somehow got the drive gear on the shaft backwards.
The champer on the drive gear isn't that pronounced is the excuse I have. Damned it I'll pull a front cover off to fix it. Never gonna happen.
It's also possible that the front pulley came off another engine and that MIGHT be the problem. I've read several places where they CLAIM that the front pulley and hub are not the same for every engine. Therefore if you put a pulley and hub off one engine on the other engine, the timing marks won't be the same and the timing will be off. I've a real problem with that. It's a production engine and every engine has the same timing.
There is a way to *FIX* that problem if true (pulley off another engine). You get/buy a Racing Beat front pulley/hub. THAT Pulley/hub is a one part outfit. No bolts to hold the pulley to the hub. Plus it has four timing marks. I forget what they are. One is TDC. HIGGEY claims this is the way to go if you suspect the wrong pulley/hub is on the engine. He says what he does is use the RB pulley/hub to remark the old used pulleys he's collected.
It sounds like your problem might be the drive gear put on backwards because you say the engine sounds better the closer you get to the marks.
Yes. I took a christmas tree rotary file to the slot so I could turn the CAS more towards the retard position i.e. CCW. Car runs like a top and passes emissions testing each year.
This problem came up just after I rebuilt the engine. It drove me up a tree because I'd never had this problem before on a rebuild and I KNEW I had used the same pulley on the rebuild that it came with. Common sense told me I somehow got the drive gear on the shaft backwards.
The champer on the drive gear isn't that pronounced is the excuse I have. Damned it I'll pull a front cover off to fix it. Never gonna happen.
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06-01-08, 11:43 PM
#8
LMAO...
yeah i doesnt look like ill be pulling the front cover of anythime soon. ill give this a try and post my results.
thaks alot HAILERS...looks like you post alot about timing and such...ive searched for this problem and your name shows up alot.
yeah i doesnt look like ill be pulling the front cover of anythime soon. ill give this a try and post my results.
thaks alot HAILERS...looks like you post alot about timing and such...ive searched for this problem and your name shows up alot.
06-01-08, 11:58 PM
#9
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Read the following thread. Well, read the fifth reply by AGreen. When I read what he wrote there, I KNEW that I had made the right decission years ago to gring out the slot in the CAS.
This: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/need-help-setting-ignition-timing-703971/
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This is what he said:
Warm the engine to operating temp, jumper the initial set coupler, then set timing. If it gets 'maxed out', then remove the cas and turn it one tooth, replace, retry.
I had a similar problem after rebuilding. I installed the CAS drive gear backwards. Maxed out, I was getting about 3mm away from the points lining up, so I moved the cas one tooth. Now, maxed out the opposite direction, I was still 3 mm away. Removed the front cover to find the drive gear flipped. Reassembled and checked timing. Bingo- dead on
This: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/need-help-setting-ignition-timing-703971/
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This is what he said:
Warm the engine to operating temp, jumper the initial set coupler, then set timing. If it gets 'maxed out', then remove the cas and turn it one tooth, replace, retry.
I had a similar problem after rebuilding. I installed the CAS drive gear backwards. Maxed out, I was getting about 3mm away from the points lining up, so I moved the cas one tooth. Now, maxed out the opposite direction, I was still 3 mm away. Removed the front cover to find the drive gear flipped. Reassembled and checked timing. Bingo- dead on
06-02-08, 12:18 AM
#10
there is a picture in this post on how your CAS should look like when you stabb it. tomorrow im gonna go ahead and try this at the shop. then ill let you know how everything went.
if i get in the "f*ck this lets fix the problem right now" mood, i might pull off the front cover of.
im thinking about what you said in another post...checking TDC on your rotor housing with a mirror and a flex light. not so sure right now ill see tomorrow.
if i get in the "f*ck this lets fix the problem right now" mood, i might pull off the front cover of.
im thinking about what you said in another post...checking TDC on your rotor housing with a mirror and a flex light. not so sure right now ill see tomorrow.
06-02-08, 07:07 AM
#11
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****im thinking about what you said in another post...checking TDC on your rotor housing with a mirror and a flex light. not so sure right now ill see tomorrow.
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Please ignore that method. SINCE then I've come to the conclusion that won't work, at least not on a series four engine and will NOT be accurate. That method depends on the sparkplug holes being equal distance b/t the *high* area b/t them. I took a couple of spare series four housings in hand and did some measurements and found that is NOT the case.
That method is ok if you have no marks on the pulley at all , and are just trying to get in the BallPark with TDC.
The only accurate method I've found is to find TDC by liquid displacment. I mean, find close to TDC using the mirror method. Then pull the sparkplugs on the fwd housing. Insert two pieces of 1/2" vynl tubing in the front sparkplug holes (a foot in length or so). Then using a squirt can, fill the lower vinyl hose until oil comes out the top vinyl hose. Keep filling til the top hose gets almost full.
Then with a socket on the front pulley nut, move the eccentric shaft back and forth in Small Increments. When you do that the oil in the tubes will rise in one direction and fall in the other. As it rises, you keep turning the eccentric shaft. When the oil starts FALLING in the hose, THAT is the TDC position, where the oil just starts falling. So you make a mark on the pulley across from the fixed pin when you get to that falling point.
I do/did this several times one time after the other to make sure I got the same results each time. One time I didn't. That was because of air in the lines confusing me. IT's a messy process. I wrote a thread called TDC or Finding TDC or something like that. It helps to have ALL the sparkplugs pulled so when the front pulley bolt is turned, there will be less resistance turning the front pulley bolt.
I more or less KNEW why that 86 was not acting right. That is one reason I did the elongated slot. I KNEW it wasn't the pulley because I used the same pulley. IN your case that isn't a known, so it'd be interesting if you pulled the front cover and reinstalled the front CAS drive gear and then see what happens.
I suppose pulling the front cover isn't that big a deal. It's those six or seven bolts that attach the pan to the front covers bottom that are a bit of a hassle.
And one very LAST thing. I think you have the AGreen/HAILERS front drive gear problem rather than the wrong pulley problem. With the Wrong Pulley Problem, the CAS can still be turned to hit the marks on the pulley, whereas the wrong drive gear problem results in Not being able to hit the marks turning the CAS.
AGreen is my CAS drive gear hero.
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__________________
Please ignore that method. SINCE then I've come to the conclusion that won't work, at least not on a series four engine and will NOT be accurate. That method depends on the sparkplug holes being equal distance b/t the *high* area b/t them. I took a couple of spare series four housings in hand and did some measurements and found that is NOT the case.
That method is ok if you have no marks on the pulley at all , and are just trying to get in the BallPark with TDC.
The only accurate method I've found is to find TDC by liquid displacment. I mean, find close to TDC using the mirror method. Then pull the sparkplugs on the fwd housing. Insert two pieces of 1/2" vynl tubing in the front sparkplug holes (a foot in length or so). Then using a squirt can, fill the lower vinyl hose until oil comes out the top vinyl hose. Keep filling til the top hose gets almost full.
Then with a socket on the front pulley nut, move the eccentric shaft back and forth in Small Increments. When you do that the oil in the tubes will rise in one direction and fall in the other. As it rises, you keep turning the eccentric shaft. When the oil starts FALLING in the hose, THAT is the TDC position, where the oil just starts falling. So you make a mark on the pulley across from the fixed pin when you get to that falling point.
I do/did this several times one time after the other to make sure I got the same results each time. One time I didn't. That was because of air in the lines confusing me. IT's a messy process. I wrote a thread called TDC or Finding TDC or something like that. It helps to have ALL the sparkplugs pulled so when the front pulley bolt is turned, there will be less resistance turning the front pulley bolt.
I more or less KNEW why that 86 was not acting right. That is one reason I did the elongated slot. I KNEW it wasn't the pulley because I used the same pulley. IN your case that isn't a known, so it'd be interesting if you pulled the front cover and reinstalled the front CAS drive gear and then see what happens.
I suppose pulling the front cover isn't that big a deal. It's those six or seven bolts that attach the pan to the front covers bottom that are a bit of a hassle.
And one very LAST thing. I think you have the AGreen/HAILERS front drive gear problem rather than the wrong pulley problem. With the Wrong Pulley Problem, the CAS can still be turned to hit the marks on the pulley, whereas the wrong drive gear problem results in Not being able to hit the marks turning the CAS.
AGreen is my CAS drive gear hero.
Last edited by HAILERS; 06-02-08 at 07:18 AM.