Engine Problems with my 80 RX7 :(
11-25-10, 09:55 AM
#1
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Engine Problems with my 80 RX7 :(
I noticed over the summer than my mazda was burning through oil like a flaming oil spill.... I would change the oil then less than 2k miles later i would need to put in 3 quarts. Now the damn thing wont even start. I was driving it on the highway, Oil light came on the dash and the engine shut off. Tried to start it after that but it wouldn't. I would turn the ignition and give it gas, it would try to start but i didnt want to burn the starter out so i would only let it try for a few seconds at a time. Also after I turn the key out of ignition, the car would backfire. Anyone have any ideas to what the problem might be?
Last edited by d_eagz13; 11-25-10 at 10:04 AM.
11-25-10, 10:47 AM
#2
Waffles - hmmm good
iTrader: (1)
Lots of ideas but not enough info to diagnose really. Can you describe the
oil loss better, like, was there any leaks? Where? What color was the exhaust?
Did it stink more than usual?
Oil light and then engine shutoff doesn't make a lot of sense because the car
doesn't have the smarts to shutoff on low oil. Something else happened. You
need to make sure it still has compression and then try getting it started with
clean or new plugs as if it was flooded. It sounds like the plugs are fouled to
me. It may have overheated also but you didn't mention the temp guage when
it died.
oil loss better, like, was there any leaks? Where? What color was the exhaust?
Did it stink more than usual?
Oil light and then engine shutoff doesn't make a lot of sense because the car
doesn't have the smarts to shutoff on low oil. Something else happened. You
need to make sure it still has compression and then try getting it started with
clean or new plugs as if it was flooded. It sounds like the plugs are fouled to
me. It may have overheated also but you didn't mention the temp guage when
it died.
11-25-10, 11:27 AM
#3
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Was the oil light the only one that came on? If you lost your electricals, then all of the dummy lights would've come on at once. No power to the ignition system would result in immediate shutdown, and refusal to restart. If this is the case, then check the fusible links on the driver's side strut tower.
The other possibility would be loss of the leading or trailing ignitor. Still got spark at the plugs? That will be the test that really narrows things down for us.
Good luck.
.
The other possibility would be loss of the leading or trailing ignitor. Still got spark at the plugs? That will be the test that really narrows things down for us.
Good luck.
.
11-25-10, 12:05 PM
#4
3 quarts per 2k miles is not abnormal at all. That's only 667miles/qt. which is within the factory specs for NEW engine, depending on driving conditions.
From the '80 Owners Manual, Page 1-1:
Page 3-14, "ENGINE OIL LEVEL WARNING LIGHT"
Once you pass the "less than 250 miles per quart" line, you're pretty much looking at a rebuild somewhere in the near future.
But if you're going 2,000 miles without checking your oil, the problem is you, not your car. You can ignore oil levels with a modern vehicle and get away with it (mostly), but not with a 30-year-old rotary.
Letting the oil get low enough that the light comes on is real bad, as the light doesn't come on til you're damn-near completely dry on oil - and that's a death sentence for a rotary. Engine life with the low oil light on is measured in minutes. Bearing failure and rotor overheat, and then destruction of the engine, follows rapidly.
It does sound like you've had an ignition/electrical problem rear it's head, unless you didn't notice the light coming on until the engine stopped running.
Check spark and compression. Hopefully, you just lost an ignitor or coil.
But check your oil every time you buy gas.
Most guys carry a quart, just in case.
From the '80 Owners Manual, Page 1-1:
Check the engine oil at EACH FUEL STOP.
NOTE - it is normal for your rotary engine to consume oil, since the rotary engine uses oil to lubricate the gas seals by metering oil into cmbustion chambers. The oil comsumption rate is normally 1,000 miles/qt. The rate, however, may vary depending on the driving conditions. Because of these variables, the oil consumption rate can be increased to 500 miles/qt.
NOTE - it is normal for your rotary engine to consume oil, since the rotary engine uses oil to lubricate the gas seals by metering oil into cmbustion chambers. The oil comsumption rate is normally 1,000 miles/qt. The rate, however, may vary depending on the driving conditions. Because of these variables, the oil consumption rate can be increased to 500 miles/qt.
If the light comes on while driving:
1. Pull safely off the road and stop your car.
2. Check the engine oil level. If the oil level is low, add oil as required or,
3. Tow your car to the nearest gas station or Mazda dealer to add oil.
1. Pull safely off the road and stop your car.
2. Check the engine oil level. If the oil level is low, add oil as required or,
3. Tow your car to the nearest gas station or Mazda dealer to add oil.
But if you're going 2,000 miles without checking your oil, the problem is you, not your car. You can ignore oil levels with a modern vehicle and get away with it (mostly), but not with a 30-year-old rotary.
Letting the oil get low enough that the light comes on is real bad, as the light doesn't come on til you're damn-near completely dry on oil - and that's a death sentence for a rotary. Engine life with the low oil light on is measured in minutes. Bearing failure and rotor overheat, and then destruction of the engine, follows rapidly.
It does sound like you've had an ignition/electrical problem rear it's head, unless you didn't notice the light coming on until the engine stopped running.
Check spark and compression. Hopefully, you just lost an ignitor or coil.
But check your oil every time you buy gas.
Most guys carry a quart, just in case.
11-27-10, 10:17 AM
#6
Oil consumption depends a lot on how heavy a foot you have, too.
Lots of WOT time = higher oil consumption. The oil metering pump is linked to the throttle.
3 qts per 1000 miles is a little high, but still depends on how you drive. Time to start paying attention to your exhaust (looking for smoke) and your plug condition. You'll know it's time when your plugs come out looking like the bottom of a turkey-roasting pan.
Lots of WOT time = higher oil consumption. The oil metering pump is linked to the throttle.
3 qts per 1000 miles is a little high, but still depends on how you drive. Time to start paying attention to your exhaust (looking for smoke) and your plug condition. You'll know it's time when your plugs come out looking like the bottom of a turkey-roasting pan.
11-27-10, 01:21 PM
#7
Lives on the Forum
If the motor is getting up there in age (miles), consider doing what I do.
1. Change oil frequently (about every 3k miles). Lately I've been using Lucas 20/50 oil, just because everything else they make works as advertised (which is pretty rare these days).
2. Replace one quart of oil with one quart of Lucas Heavy Duty Oil Stabilizer (LHDOS, from now on).
3. Run a can of Seafoam through the tank every month or so. I do this because older motors have lower compression, and lower compression = higher rates of carbon deposits. Carbon deposits can lower the compression even further by preventing the apex seals from moving freely, so the problem can compound in a way that can get you into trouble fast if it gets out of hand (flooding issues, broken seals, etc.). The Seafoam, along with regular trips to the redline, seems to keep the motor happiest.
This seems to work well for me. I put a lot of miles on the car, plus crazy racing on weekends, the occasional 2k miles trips to the Dragon, etc. When the original motor coughed up an apex seal at 213,000 miles I replaced it with a junkyard motor of unknown mileage, just because the class I race in prevents me from running anything fancy in the way of motors.
Anyway, since I don't know how many miles are on it, I'm using this method on that motor too. Seems to work very well, especially if the motor is getting to the point where it is using a bit more oil than it should be.
Anyway, that's just my experience/views/theory/belief/etc. on the matter. As always, your mileage may vary.
.
1. Change oil frequently (about every 3k miles). Lately I've been using Lucas 20/50 oil, just because everything else they make works as advertised (which is pretty rare these days).
2. Replace one quart of oil with one quart of Lucas Heavy Duty Oil Stabilizer (LHDOS, from now on).
3. Run a can of Seafoam through the tank every month or so. I do this because older motors have lower compression, and lower compression = higher rates of carbon deposits. Carbon deposits can lower the compression even further by preventing the apex seals from moving freely, so the problem can compound in a way that can get you into trouble fast if it gets out of hand (flooding issues, broken seals, etc.). The Seafoam, along with regular trips to the redline, seems to keep the motor happiest.
This seems to work well for me. I put a lot of miles on the car, plus crazy racing on weekends, the occasional 2k miles trips to the Dragon, etc. When the original motor coughed up an apex seal at 213,000 miles I replaced it with a junkyard motor of unknown mileage, just because the class I race in prevents me from running anything fancy in the way of motors.
Anyway, since I don't know how many miles are on it, I'm using this method on that motor too. Seems to work very well, especially if the motor is getting to the point where it is using a bit more oil than it should be.
Anyway, that's just my experience/views/theory/belief/etc. on the matter. As always, your mileage may vary.
.
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11-27-10, 02:21 PM
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If the motor is getting up there in age (miles), consider doing what I do.
Run a can of Seafoam through the tank every month or so. I do this because older motors have lower compression, and lower compression = higher rates of carbon deposits. Carbon deposits can lower the compression even further by preventing the apex seals from moving freely, so the problem can compound in a way that can get you into trouble fast if it gets out of hand (flooding issues, broken seals, etc.). The Seafoam, along with regular trips to the redline, seems to keep the motor happiest.
.
Run a can of Seafoam through the tank every month or so. I do this because older motors have lower compression, and lower compression = higher rates of carbon deposits. Carbon deposits can lower the compression even further by preventing the apex seals from moving freely, so the problem can compound in a way that can get you into trouble fast if it gets out of hand (flooding issues, broken seals, etc.). The Seafoam, along with regular trips to the redline, seems to keep the motor happiest.
.
11-27-10, 05:30 PM
#10
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You know, everybody wants to make it more complicated than it needs to be.
Yes, whole can at once. It doesn't even matter how much gas you have in at the time. I've done it with 1/16th to full, and always get great results.
It's when you start trying to make it difficult that you start hearing the horror stories: "I put half the can in the tank, and sucked the other half in through a vacuum line. Now my car won't start.", or "I read the directions, and they said to put it in the oil. Now my motor is smoking like a crack ***** and I think I hear a knocking noise."
Seriously, just dump it in the tank and enjoy the newfound power and responsiveness.
Yes, whole can at once. It doesn't even matter how much gas you have in at the time. I've done it with 1/16th to full, and always get great results.
It's when you start trying to make it difficult that you start hearing the horror stories: "I put half the can in the tank, and sucked the other half in through a vacuum line. Now my car won't start.", or "I read the directions, and they said to put it in the oil. Now my motor is smoking like a crack ***** and I think I hear a knocking noise."
Seriously, just dump it in the tank and enjoy the newfound power and responsiveness.
11-27-10, 06:02 PM
#11
Full Member
make sure you are running the right oil weight too - in Buffalo you can get away with as heavy as 20-50 from mid June- end of Aug;if you were running 5-30 that could cause it to burn more than you expected.
11-28-10, 02:39 PM
#12
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Thread Starter
wow thanks for the help everyone.... Car only has 100k miles. Bought it from a friend who moved to CA, sat in a garage for its whole life. I was only worried because it was driving perfect (for a 30 yr old car) no problems other than a small exhaust leak which doesn't even sound bad. Plus i completely changed the interior from the seats to the rear window and was looking forward to showing it off. I didn't have time to try n fix it initially so I just put my subaru on the road for the winter.
11-29-10, 02:53 PM
#13
Are you running the stock exhaust? If yes, and if local laws allow, fixing your exhaust leak (most probably in the downpipe or "Air Duct") by switching to a header/pre-silencer will make you a surprising amount of additional power (5-10% or so over stock), with no mechanical downside.
I've become a reluctant expert on the stock '80 exhaust and emissions systems over the years. The time I swapped in a header/pre-silencer from Racing Beat made me nearly cry when I had to switch back for smog purposes.
I've become a reluctant expert on the stock '80 exhaust and emissions systems over the years. The time I swapped in a header/pre-silencer from Racing Beat made me nearly cry when I had to switch back for smog purposes.
12-09-10, 09:32 AM
#14
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I had thought about it, I have the muffler and a catalytic converter to put on but i never bought the rest of it. Right now its buried under 4 feet of snow tho so I cant do much until the snow melts. Do you have any pictures of your interior on your 80? I did some drastic changes from the seats to the back also. The 2nd pic was taken before hiding the wires and finishing the misc trim but I think it turned out alright.
12-09-10, 10:34 AM
#15
If you've got a stock '80, you don't have a catalytic converter at all; last year of pre-cat construction for the RX-7's. You have a thermal reactor based, coaxially-ducted, heat exchanger exhaust system.
Here's the main working parts:
(If your car's a non-California build, you probably won't have the EGR, which sits on top the engine between the carb and the ratsnest.)
Some, from various points in time (that's why the shift **** keeps changing, heh). I did a complete reupholstery job based around FB seats a few years back, and installed FB bins for added storage. I also converted the car for electric mirrors and windows.
One that Larry Chen shot for SpeedHunters at SevenStock this year: Much better photographer than me!
Here's the main working parts:
(If your car's a non-California build, you probably won't have the EGR, which sits on top the engine between the carb and the ratsnest.)
Do you have any pictures of your interior on your 80?
One that Larry Chen shot for SpeedHunters at SevenStock this year: Much better photographer than me!
12-09-10, 12:52 PM
#16
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Thread Starter
The piece of exhaust was referred to on the website as a converter, actually is the heat exchanger lol. And my problem with the exhaust is actually the air pipe, mainly because it is not there. It doesn't sound bad tho, gives it a little more grumble. I spent most of my time over this summer painting all the interior/exterior trim a glossy black and finishing the center compartment . Wish I had more time to work on it, the system sounds amazing tho for the little money I spent on it. Dynomat all around the back. I couldn't believe how much room it had once i removed those aluminum mid section pieces. Your upholstery looks awesome, I like the little rotary emblem. How much did power windows cost you?
12-09-10, 02:22 PM
#17
Electric regulators were junkyard takeouts from an FB, cost something like $30 each back when I bought them. Direct bolt-in.
Wire, switches (you can see them in the coin tray slots in the shift surround - would have done it differently had I known then how rare those parts would get!), fuses, etc, probably another $30-40 all-told.
Quite a bit of tinkering and cussing to work out my wiring & dress it neatly.
Wire, switches (you can see them in the coin tray slots in the shift surround - would have done it differently had I known then how rare those parts would get!), fuses, etc, probably another $30-40 all-told.
Quite a bit of tinkering and cussing to work out my wiring & dress it neatly.
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