The Fiero quit suddenly this morning after running great ever since we bought it last spring. As my daughter drove it on to an off ramp it bucked a few times and then died as she tried to pull away at the light when it changed to green (I was driving another car in front of her so I wasn't in the car - we were headed to an autocross). I was able to get it started and sort of keep it running by feathering the throttle with my left foot on the brake as I shifted in to drive (if I didn't keep giving it extra throttle it would die), it was coughing and sputtering as I pulled it through the intersection and on to a safe spot on the shoulder. Also it was very reluctant to start, almost like it was initially firing against itself (like the old points type ignition cars would do if you had the timing way off. I drove home, got the truck and trailer and picked the car up. I was able to get it started enough to load it and to put it in the garage when I got home, but it was barely running. This is a car that has run great ever since we got it, even though my daughters have been autocrossing it all summer. The car is an '87 GT all stock with a 2.8 liter and 3-speed auto.

My first thought was fuel pressure regulator or pump, unfortunately I couldn't check that properly since my fuel pressure gauge decided to spring a leak, so I need to get another one. I did hook up my code reader / scanner and with the key turned on there weren't any codes set and everything seemed to be looking okay when I scanned everything (TPS etc.). I did see a lean flag was set. Also when I drove it in to the garage I checked the oil pressure and other gauges and everything looked normal. After scanning it, I tried a little to start it, but it wouldn't quite start (it had been sitting several hours at this point). I did see quite a bit of exhaust smoke in the garage after trying to start it. Any ideas? It was running great right up until it quit, there wasn't any earlier indication that something was wrong. I suppose the timing chain could have jumped a tooth, but it would have been odd for it to do it then when she was slowing up after driving 20 miles at 65 mph. Thanks

Check fuel pressure. Sounds like a failing fuel pump. 40-45 psi at 2 second key on prime, should hold for several minutes.

Maybe clogged fuel filter.

quote Originally posted by Frizlefrak: Check fuel pressure. Sounds like a failing fuel pump. 40-45 psi at 2 second key on prime, should hold for several minutes.

Thanks for the specs. A soon as I get a new test gauge I will try that. The gauge I had started leaking internally as soon as I tried it this afternoon. My guess, from as quickly as it happened and from the way that it is acting, is that the fuel pressure regulator diaphram sprung a leak. I guess that I could blame it on the 10% ethanol that Missouri mandates in the gasoline, though I guess that it could be becuase it is 25 years old. I did replace the fuel filter when I got the car, I don't think that is it since it went from running great to running like crap so quickly.

I have had 3 Fieros that suddenly quit running, like someone turned off the key. Everytime it was the same problem. The ignition module in the distributer.
Make sure to use the thermal paste that comes with it or you will evenually have the same problem again.

quote Originally posted by typhoon: I have had 3 Fieros that suddenly quit running, like someone turned off the key. Everytime it was the same problem. The ignition module in the distributer. Make sure to use the thermal paste that comes with it or you will evenually have the same problem again.

Ignition Module is most common, and I had an issue with mine and it had same problem you did.. Autozone can test modules.

quote Originally posted by typhoon: I have had 3 Fieros that suddenly quit running, like someone turned off the key. Everytime it was the same problem. The ignition module in the distributer. Make sure to use the thermal paste that comes with it or you will evenually have the same problem again.

while it is a common failure i don't think that is his problem. usually when they go out they will quit and then won't fire at all. let it sit for an hour and then they might work again but not for long. i think that either the fuel pressure reg is fubared or the fuel pump is getting ready to go. the fuel pressure will tell you if it is either one

also check all your vaccum lines... it sounds like your having the same problem i am, if you fix it let me know what it turned out to be so i can see if it is the same issue or not... my car suddenly stopped running as i was stopping at a stop sign in a residential doing 20mph... and last time i tried to run it... ( to move it from the driveway to the garage) there was smoke everywhere...

quote Originally posted by dudewithoutfiero: while it is a common failure i don't think that is his problem. usually when they go out they will quit and then won't fire at all. let it sit for an hour and then they might work again but not for long. i think that either the fuel pressure reg is fubared or the fuel pump is getting ready to go. the fuel pressure will tell you if it is either one

This is symptomatic of fuel system failure, not ignition, so that's where I'd start my troubleshooting.

but would that cause all the smoke? u must consider all symptoms when diagnosing

I will work on getting a new fuel pressure test gauge on the way home tonight, if I don't get one I should be able to pull the vacuum line that is connected to the fuel pressure regulator and see if fuel is running out of it, which it would be if the diaphram in the regulator has sprung a leak. Don't think it is the ignition module if it shuts the car off when it fails, the car was still running, just very poorly. One other thing I read in another thread (seems about three threads with similar problems have cropped up all of the sudden) is that there a seperate fuses for each bank of injectors, so I might check those if the fuel pressure is okay. The way that it is running seems like it could be trying to run on three cylinders, especially since that could be making it fire at the wrong time when I am cranking it. Could even be the distributor cap if it is cracked or has carbon tracks inside - I had something similar happen about 30 years ago in a '72 Oldsmobile while I was driving at 130+ mph and it quit and would fire but wouldn't run.

Honestly untill he starts testing each system were not gonna know. You need to check if its getting fuel, if its getting a spark ect.

quote Originally posted by Phirewire: Honestly untill he starts testing each system were not gonna know. You need to check if its getting fuel, if its getting a spark ect.

Troubleshoot, don't guess.

Mine did the same thing a while back, and it turned out to be worn out wiring. That was diagnosed after a number of other "fixes" that ran into quite a bit of expense. At least I don't need fuel injectors, distributor, timing chain and gears, fuel pump, etc. for some time (I hope).
Good luck!

My Mothers Fiero did the same thing, she was zipping down the highway for nearly and hour and just as she started to get home it coughed and lacked power. Hard to start, I grabbed my spare parts bin and went to work, changed coil, then module, then entire distributor, still didn't want to run, I was praying what I thought it was, was not the issue. However the simplest way to check for a bad timing chain is advance the hell out of the timing, Stock is between 10 and 12 degrees. I cranked it up to about 30 degree's and hit the key it fired up and ran, poorly but it ran enough for me to drive it around to the house. It had jumped time due to a sloppy chain. I tore it down, and replaced the chain and cam gear. (left the crank gear on, yes I know that is supposed to be bad, but its been 2 years of daily driving and no issues)

If I were you, I would check everything else first as the timing chain swap can be a real Pain in the A$$. When you are in there, you might as well replace the water pump while you are at it.

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its a V6, Its most likely the ignition module. The symtoms are exactly what you said. In most cases, if you let it set for 1/2 hour, it starts right back up and runs fine. A lot of times, it will even restart a few seconds later.

[This message has been edited by rogergarrison (edited 10-08-2012).]

Here is more info. I just checked the fuel pressure. Runs up to 38 psi with the first key bump then 40 psi with the second one. After 10 minutes it was still at 38 psi, so I don't think that it is the fuel pressure regulator. I pulled out the air cleaner, took of the air intake hose and looked inside the intake, with a flashlight and a mirror. Nothing was blocking the intake (had a mouse eat up the air cleaner in my '89 MR2 years ago and a big wad of the stuffing got sucked in and jammed the throttle body so it would go below 5,000 rpm, that was fun driving through town!), so it wasn't that either. Did a good visual inspection of the engine for loose vacuum lines, worn wires etc. and couldn't see anything.

I know several people mentioned the ignition module, but they also seem to mention that if that was bad, that when it would cool down it would run. That isn't the case here. I managed to barely get it started tonight and it didn't run any different. When I was cranking the engine it was firing against itself part of the time (which would really slow down cranking rpms), when it didn't do that it cranked very quickly. When it finally started it would only run by giving it extra gas and even then it coughed and sputtered and smoked. When I tried to get the rpms higher it wouldn't make any difference. When I let up on the gas it quickly died. I checked the fuel pressure gauge and it was at 40 psi. Also, if the ignition module was bad, wouldn't it set a code? When I scanned it and checked for codes (using my old AutoXray scanner that is set up for both OBD I and OBD II.

I also checked the oil for water in case I had blown a head gasket, but didn't see any. I guess that it is time to pull out the manual and start going through the diagnostics. I was hoping for something, easy to find since it went from running great to running like crap so quickly.

Does the tach sit at zero when you crank? This is a sure sign of ignition trouble, likely the module. If the tach doesn't move when cranking, try plugging and unplugging the connectors, then take it out and have an autoparts store test it. Module was my first thought. On an older car I would say coil, but modules are easy to check and seem much more likely on Fiero's. Coils seem to be replaced unneccesarily most of the time in these cars.

We only said it may restart MOST times. If it gave up completely it wont. I never had a bad module throw a code. Ive had prob 1/2 dozen failures on 3 diff cars. Not one time did the chk eng lite come on to indicate a code.

Checked it and the tach worked fine while cranking and while running (still ran like crap). I have the applicable service manual downloaded at work, unfortunately I can't get it to open on my home computer. I had scanned everything with it running and wanted to check all of the scanned settings to see what was high or low. Guess that I will have to wait to do that. After running it for a few minutes I shut it down and looked at the engine - the exhuast pipe was cherry red, which I assume means it was running rich and dumping unburned fuel in the pipe. I do see that the "rich" flag is set (when I scanned with the engine off after parking in the garage the "lean" flag had been set). Also, the injection pulse is 5.1 mS, but since I can't look at the manual right now I don't know if that it low or high.

the cherry red exhaust manifold could be a really lean condition or the timing is wrong.

Pulled the ignition module and had it tested. It was fine, they tested it four times and made sure it got good and hot. I also checked the fuel injection fuses, both were fine. When I scanned the engine with it running (barely running), the only things that were really out of whack were the Injection pulse, it was 5.1 mS where the spec, from the FSM, is .7-2 mS, and the map sensor, which was 3.35 v, with a spec of 1-2 v. I don't know if these are out of whack because the engine was running so poorly, and the system was trying to compensate, or because of what ever is wrong. Also, the spark advance was 31.5% at 2000 rpm, that seems a little high but I'm not sure what it should be.

I guess now I will try and check for the cat being plugged by pulling the O2 sensor (to give the exhaust a place to escape). If it isn't that I'm not sure where to go next.

I post file often for problems like yours:


Your’s could be a common problem and don’t cost anything to check.
Try this:
Watch the tach when cranking if it don’t move you're not getting pulses from the distributor. If so, it could be a faulty module in it or more likely simply corroded connectors at the base of the distributor. Reseating those connectors a few times could clean the pins some and also do the same to the connectors on the coil etc. These cars are old, and old connectors corrode. Such can also manifest itself as intermittent misfires, and engine cutouts.

BTW: lots of folks keep replacing modules and coils thinking they are bad because the new ones FIX the problem, when in actuality the fact that they simply unpluged the connectors and repluged them into the new unit cleaned the contacts enough to make it work again, at least for a while. It's smart, to replace those old connectors with new ones.
BTW: Cliphouse has those connectors

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Actually I've always had a tach signal when cranking and running

USE HEAT SHRINK COMPOUND WHENEVER YOU INSTALL THE ICM, unless you like replacing them.

The fact that it doesn't appear to be the module and the timing is off twenty degrees or more (it's supposed to be about 10 degrees before top dead center), it might be a mechanical timing issue. In other words if it's not the harmonic balancer slipping, it's probably the timing belt. People have discovered that the harmonic balancer can come apart so that the outside ring, the part that happens to have the timing mark on it, slips relative to the crankshaft, making it approximately impossible to set the timing. You should probably search for those threads and check to see if your harmonic balancer is lined up correctly. If it is, you might want to consider one of the many swap threads. If you think about it, this couldn't have happened at a better time, assuming you have someplace warm to work over the winter.

Sorry. After reading again I see that the timing was apparently without jumping the pins to take the ECU out of the picture. If the computer is setting the timing thirty degrees at two thousand rpm might be just fine. I also forgot about the clogged cat. That does sound like you might be on the right track. Relative to changing the timing belt, the cat is probably nice. However, I think the thing that would be most likely to fail suddenly under the circumstances you describe - well, think about it. I was looking for the harmonic balancer thread and found one that started out like yours and investigated the harmonic balancer angle. It ends with a post about the timing belt. Good luck!

[This message has been edited by 85 SE VIN 9 (edited 10-16-2012).]

Thats just another reason I set timing by ear/ trial and error and throw away the timing light.

Actually the timing measurement was from my scanner so that is what the ECM was seeing.

It sounds like the timing is ok, but you might want to check it after jumping the pins. If you have a timing light it would be worth your time to check. Also, before you believe me about the timing belt you might try checking or even replacing the coil. I had a coil go in another car under similar circumstances and was told it was the timing belt, but I was stubborn. I spent the whole summer in that little Indiana town (which will remain nameless to protect the guilty) until I managed to order and install a coil - problem solved.

Just some updates on what I tried last Saturday (I had been out of town for a week so I didn't get a chance to work n it until Saturday). I got some heat sink compound and remounted the ignition module, got some anti-seize and reinstalled the O2 sensor, then jacked up the car and cut off what turned out to be a perfectly good catalytic converter. I figure I was in trouble when I looked through it and it looked brand new. I started the car up and it ran pretty much the same, maybe slightly better. Since my daughters wanted to autocross the car the next day I went and bought a new ignition module (just in case, plus it wasn't all that much and I wanted to eliminate it from the equation). That didn't change anything. I then found in the manual how to check the ignition coil, it failed one of the tests so I went and bought a new one and installed it, again no real change in how it was running. It seems to run smoother for a bit when I hold the throttle steady then it starts sputtering, backfiring and missing again. It does rev better than before and the exhaust pipe isn't glowing any more (I have a temporary pipe installed in place of the converter). This weekend I plan to go through it more and I will do a search to see what pins to jumper to disable the computer timing (as somebody mentioned). I'm thinking now either the pickup inside the distributor is bad or the timing chain jumped a tooth. One thing I would like to be able to check is to see what the static timing is. I know how to check it with a points type ignition and a trouble light but I am not sure how to check it with this type of ignition. The car won't idle at all so I can't use a timing light to check it.

I know this may sound stupid, but when is the last time you've done a full tune up? Also, I've had a similar problem before after getting gas at Thorntons and once at Caseys, it was a pain to start and when it started it ran like crap until all that crap was gone. Just saying, if you haven't replaced them, fuel filter, spark plugs, cap/coil, and wires aren't bad to change. Also, I've had a similar issue with a car from a really nasty fuel filter. Judging by how much of a PITA most of the fuel filters have been to change on the cars I have owned, I'm sure none of them were ever changed.

Crank the engine over (by hand if need be), line up the timing mark to TDC and pop off the distributor cap to see where the rotor is pointing. That'll tell you if the timing has jumped.

You can also loosen the distributor hold down and rotate the distributor while someone cranks it over and see if it starts/runs any better. If the timing has jumped and it still sort of runs then it can't be too far off......rotating the distributor may line things up enough to drive it, but if the timing chain is stretched then the timing will just migrate again.

If it wont idle, you can still use a timing light. over 2500-3000 rpm, timing should be around 35* advanced.

quote Originally posted by rogergarrison: If it wont idle, you can still use a timing light. over 2500-3000 rpm, timing should be around 35* advanced.

Maybe I can get one of the kids to help me since I can't get out of the car without it quiting. Now when I scanned it, the car's computer said the timing was 31.5 deg at 2,000 rpm so maybe timing isn't the issue since that seems to be in the ballpark of what you listed.

The car is finally back running again! It turned out to be the distributor, once it was replaced then it ran fine. Note that I had already installed a new ignition module in the old distributor. In my quest to fix this I had previously replaced the ignition module, ignition coil, spark plugs, spark plug wires, MAP sensor, removed the catalytic converter, repaired a vacuum leak on the MAP sensor / fuel pressure regulator line (which involved removing and replacing the top half of the intake manifold) and repaired a partially broken wire coming from the coil. Also had checked fuel pressure, reset the ignition timing, checked many vacuum lines, etc. Until I replaced the distributor, the only thing from that whole list of things that I did that made any difference was replacing the spark plugs and wires. It would at least start and idle after that, but it would would still backfire and miss at any constant speed above idle.

Thanks for completing the thread!

Yes, I thought that I should in case it comes up on somebody's search a year or two from now. My daughters were glad that it was running again, they had to go out cruising in it last Saturday.