So, I picked up a 1987 Fiero GT 5 Speed at a steal off of Craigslist in hopes of having a 30MPG commuter. Car has NOT disappointed in the past year, up until last week. Its a blast to drive, if I drive it right it averages 29MPG (tough to do sometimes since the car is such blast to drive on my twisty Pocono Mountain roads), and has proven very reliable up until this point. I was leaving the base (I'm in the military) last week and as I casually shifted from 2nd to 3rd, it just shut off. Like it would if I turned the key, but since it was still in the on position, the idiot lights kicked on etc. I pulled over, tried to restart it, but all it did was crank. I could hear the fuel pump humming to pressurize the line, but it just wouldn't start. I started researching (thank god for smart phones) to see if I could trouble shoot it. After about 15 minutes I decided to give it another shot and low and behold, it fired up. I flipped a U turn and headed back to base instead of tempting fate on the 4 lane. Sure enough, just after I cleared the gate, it quit again. Same way. Since then, I changed the fuel filter, and just generally did some more troubleshooting. The car starts right up. Runs anywhere from 45 seconds to 1.5 minutes, then shuts off. No check engine lights. No weird noises. I'm a ford guy besides this little guy, and I know they are quirky. So I am here, looking for someone smarter then me to give me some ideas...... Thanks in advance.
Thanks for the information thus far, and the manual pages. Unfortunately there is no parts store within 1.5 minutes of where the car is, but I'll bring my Ohm meter in to work Monday and use that diagnostic page as a guide. Preliminary research shows that to possibly be a pretty expensive piece ($300?) As I've said I enjoy the car, but my purchase was for financial reasons. Honestly, there's enough of the car there where someone who truly loves these things could probably make a nice resto out of it. Unfortunately I have enough irons in the fire where I am not one of those people. So if the fix it cost starts to rival my purchase cost, I'll probably just move on and find someone who's looking for a project to sell it to. Any other ideas are encouraged and appreciated, and I will report back with and successes or failures as they happen.
Many people on here have ICMs that seem to run about 100K miles and then after it fails they have repeated failures. Many blame it on weak aftermarket ICMs and improper or no thermal paste compound. My thoughts however are different on the root causes of many (not all) ICM "failures"
1 - If your pick up coil is going bad the troubles may come and go. The engine doesn't start at times, you replace the ICM and do some other stuff and the engine starts running. It get's blamed on the ICM, but then the "ICM fails" again and you end up fighting the ignition system. If the pick up coil is failing, it can look identical to an ICM failing. 92K miles and 26 years usually takes it's toll on the pick up coil. If it even just looks bad, I would replace it. The procedure to pull and replace it means pulling the distributor and resetting the timing after you are finished so it's perhaps a little complicated for a beginner, but do-able for most. You need a timing light to set the timing after the distributor is re-installed.
If your pick up coil looks like crap like the one on the left, and you aren't a guy who likes getting stranded on the side of the road replace it.
Note - whenever replacing the ICM, make sure you use thermal paste under the ICM. Failure to use thermal paste will cause your ICM to fail prematurely. Thermal paste <> dielectric grease. Thermal paste (for automotive use) is similar to heat sink compound for computer use. The difference however is that the automotive use variety is designed for the underhood temps and conditions. You most likely will get by fine with either thermal paste or heat sink compound. Dielectric grease however is not made to transfer heat and can cause problems in the future.
1.5 - Replace the distributor cap and rotor if they are old or their age is unknown.
2- High resistance in your secondary WILL cause the insulation in your IGNITION COIL to break down and that will allow the high voltage spark to jump to the primary. That over time will kill your ICM. So if your spark plugs are old, replace them. If you know how to use a ohm meter, check to make sure your plug wires are less than 10K/ohm. If you don't know how to use an ohm meter and your spark plug wires are old, replace them.
3 - AFTER doing the spark plugs and checking/replacing the wires, replace the ignition coil. Make sure that after you replace the coil, you don't run the engine with a spark plug wire pulled. That also will kill the insulation in your ignition coil.
This video talks about high resistance in the secondary, it however is about DIS (distributorless) ignition. The same problems do occur with the Fiero ICM/Distributor ignition system.
While you are there, you can consider replacing the ICM - Coil wire. A little bit of a shotgun approach (replace everything) but the cost of the wire is much less than the cost of a tow. btw, it is me selling both of them, fyi.
Why replace all of this? Because these things can work and then fail. It's a huge headache to get stranded. Any competent shop would replace these because they know if anything fails after the first repair, they will be making the additional repairs at their cost.
Your original ignition system lasted for 92K miles. The replaced ignition system can also last for 92K miles. Or it can last for 92 miles.
Man. You guys are nothing if not thorough. How much of that can be swapped without dropping the engine. I'm curious what the alternate method if changing out the forward plugs is. I can run a timing light and an ohm meter.
Some swap the front plugs from the top and can snake their skinny arms down there without removing the rear deck lid.
Pretty much anyone can get the plugs out of you take the four bolts out that hold on the rear deck lid. It gives you quite a bit of room to get to the plugs. When pulling the rear deck lid, ONLY the 4 - 13mm headed bolts need to be removed. You also have to unplug the wires that run to the deck lid. Do not remove the specialty bolts that hold on torsion bars.
ignore the bottom right circle.
You can also get them from underneath if you are fairly inflexible.
You do not have to drop the engine to replace spark plugs.
[This message has been edited by phonedawgz (edited 10-19-2014).]
Honestly I didn't watch the tach when I was cranking and it wouldn't start. If it repeats that behavior I'll take a look. But everytime since the first time its started and then just quit a minute or so later, so Ive been watching for the check engine light, listening for the fuel pump, and watching the voltage needle. I am admittedly a Fiero rookie, and have always heard those plugs required an engine lift to get to. I hadn't even entertained the idea enough to do any science of my own on the subject. But if its that easy to do I'll put it on the list. Provided I can get it to run long enough to get it off base and get it home. I'm trying to AVOID a car trailer scenario... Seriously, thanks for the info guys. Keep it coming.
So I grabbed a new ICM and swapped it out at lunch. So far it appears to have fixed the problem. The pick up coil did look like garbage though, so I may end up swapping that to, but the main concern is getting it back onto my own personal piece if dirt versus do parking lot maintenance on base. Thanks to all for the help. Made narrowing down the problem much faster.
Good job on the module. I'd have to agree with the others that the pickup coil should also be replaced. It might be easiest to just replace the whole distributor. You might also want to replace the pigtails that connect to the distributor and coil. Not all that cheap, but so often these wires have become brittle with age and heat. Chances of these things being in good shape are minimal. BTW, try having the old module tested. If it tests good you could keep it as a spare, but more importantly you'll know to keep looking for the problem so it doesn't leave you stranded again.
I actually just replaced my pick up coil this afternoon in my 87GT. Over all a pretty easy job. The other day when I started mine up, it happen to take a little longer to turn over than usual...the next day was a cool and humid day.. the car started the same way and I drove it to the store..when I tried to start it to go home, nothing... Conveniently, I was with in 5 min walking distance of an Advance Auto.. got a new Ignition Coil (mine just looked old sad) and the ICM. Replace them both in the parking lot but still nothing, no spark and no tachometer movement when turning over. Sadly, I had it towed and then picked up a new Pick Up Coil.. pulled the distributor, replaced the pick up coil, and put it back in, in a little over an hour or so.. and that's because I cleaned everything nicely It fired up instantly. I gotta say by keeping the Pick Up Coil as a 30-40K routine maintenance item, it will surely help you to avoid the dreaded tow truck situation. I'm keeping the old ICM & Coil in the car just in case.
I had a similar problem, just driving along and all of a sudden just died. Started it right back up and drove it about a quarter mile and it died again. I replaced all of the electrical stuff and it still wouldn't run. Finally I replaced the fuel pump and that worked. You said you could hear the fuel pump, I could too before it went bad, now that it has been replaced its very quiet. The fuel pump is pretty easy to replace.
I just jacked it up and crawled under it. I had never done it before so I watched the video below on how to do it. If you think that's what it is buy a good fuel pump, because I replaced it and then got it all back together and the new pump was bad so I had to do it all over again. By that time I was really good at it, and it only took about an hour. Runs great now, better than it did before and no more annoying pump whining sound.
The only time I hear the pump is when I initially turn the car on. But I will definitely keep it in mind. Does anyone where I can score a set if the posts for the spoiler? Both of mine were broken on the car, so I took it off. I'm also looking for one of the little aluminum discs with the Fiero symbol on them for one of my wheels. Again, thanks to all.