No. I didn't hit a tree. LOL This saga has been going on since early spring. I replaced the automatic transmission clutch solenoid and went for a test drive. One half of a mile later, under full throttle, I suddenly lost power and it subsequently died and barely started. The pitch of the exhaust was down an octave (half the frequency for none musicians). It had a low frequency boom to the note that was alarming to one accustomed to the correct sound of a stock gt. My first thought was that the timing chain had jumped, even though the car only has 70k miles on it. I was certainly not going to act on that hunch until I had done my best to eliminate all other possibilities. I knew what I’d be getting into and would go there only as a last resort.
A couple of years ago it was running very rough so I bought a used ECM, I think from Rodney to eliminate that possibility. It turned out to be a bad coil to distributor cable but I left the used ECM installed as it was working fine.
So following last spring’s power loss, I plugged in the ECM back in that was in car when I bought it 6 years ago as a test. I would start but immediately die. I was puzzled but blew it off and switched back to the used one.
During the months since then, I continued driving it, fiddling in vein with everything I could think of to find a problem other than the camshaft timing. Nothing I tried had any effect, so when I got laid off from my job a month ago, I thought that I’d run out of excuses. I suddenly had time and summer was past and the weather was beautiful. The old timing chain was loose as a goose (whatever that means. Perhaps geese are extraordinarily promiscuous.) This gave me confidence that my initial diagnosis was correct and that all of this work was not done in vein. WRONG! Job was done with no change other than the new chain being noisy. I switched the ECUs again with the same result: Started but wouldn’t run with the original ECU.
Throughout all of this I have played with the ignition timing to no avail. I just discovered that my timing light no longer lights. Nonetheless, I am pretty sure the ignition timing is not the problem because I can spin the distributor back and forth while its running and the symptoms never fade.
Stumped, George
[This message has been edited by gem1138 (edited 10-26-2013).]
If throughout your investigation you have not questioned the ICM, it's time that you did. They can fail in many odd ways, some having to do with too much resistance in the secondary wiring. The connectors to the ICM should be examined also.
How about the catalytic converter? A plugged or partially plugged cat will change the pitch/note of the exhaust and cause weird drivability problems too.
If I ever knew, I do not at this moment know what the ICM is. Intercontinental Missile (non-ballistic type) ?
ICM=Ignition Control Module. It's the black thing attached to the distributor with 2 plugs attached to it (one goes to the coil & the other to the main harness).
Last November I replaced the water pump and apparently did not fully reconnect a gizmo above the water pump. It has a four conductor electrical connector that, when this calamity befell me, I discovered had come loose, fallen and was chewed up by the pulley below. I soldered the wires back to no effect. This gizmo has a large vacuum connection and two small ones.
Last November I replaced the water pump and apparently did not fully reconnect a gizmo above the water pump. It has a four conductor electrical connector that, when this calamity befell me, I discovered had come loose, fallen and was chewed up by the pulley below. I soldered the wires back to no effect. This gizmo has a large vacuum connection and two small ones.
That's the EGR solenoid. It will cause a code 32, but shouldn't have anything to do with a loss of power.
When you checked/set the timing did you ground the "A" & "B" terminals on the ALDL (thing next to lighter under the black trim panel)? Just curious.....over or under advanced timing could still be the problem.
mrfiero, the converter is a good thought that I hadn't considered. I have a friend that had a BMW that she drove in deep water, causing the guts of the converter to fall apart and clog the exhaust with similar results. I pulled the guts out with a clothes hanger and all was well.
Oh. ICU is the ignition control module. I call it the ignition module. I've been through a bunch of them and have changed them in ten minutes, I am so practiced. I installed a fan in the trunk to blow air onto it and the coil. Pre-1988s had a Mickey Mouse system. I suspect that it was ineffective and thus eliminated on the 88s. My fan is like a hair dryer and is thermostatically controlled to come on at 150 degrees. At some point, some debris broke the fan unbeknownst to me and the module failed this past February, alerting me to replace the fan. Thus the module was almost new and the fan was fully functional at the time my issue arose. It has not worsened in the subsequent months so I consider it unlikely to be the source.
I rebuilt the distributor a few years ago and was enlightened by the experience. I replaced (don't remember the proper name) what is similar to a guitar pickup in the distributor. The spider like thing in the distributor acts like a guitar string. The pickup then sends the signal to the ignition module which I believe to be an amplifier to help the signal overcome the electromagnetic noise in the engine compartment. High end guitars and basses have pre-amplifiers to overcome radio noise in a similar fashion. Many have, and I am still considering, moving the module and the ignition coil into the trunk. That should work if a good shielded cable is used to carry the signal from the pickup in the distributor to the relocated module in the trunk. A heat sink, (from Radio Shack) should do a dandy job of keeping it cool. In the factory system, heat sink grease is applied between the back of the module and the distributor back plate so that heat is transferred to said plate. This plate is inches away from the EGR system, hardly a cool environment. Bad design. They mad a feeble attempt to cool it in the pre 88 Fieros as I mentioned.
I, and who wouldn't, would love to install the 420hp twin turbo, direct injection, 3.6 liter V6 instead of addressing this issue. I am guessing it might cost $30k to $40k to do it right. I'd still rather have that than a Cayman. That's be the real Porsche beater that GM engineers wanted to build years ago.
My timing light is out but the problem arose while I was driving at full throttle. It is unlikely that the timing suddenly changed, unless the timing chain jumped and I have addressed that painfully.
Many people have removed/disabled the EGR system. I am not familiar with what all is needed to do this (aside from physically removing the parts). I think you need a new chip burned for the ECM, but I am ignorant on the subject.
I would get the cat tested and see if that leads anywhere. I bought my first Fiero (an '88 GT) in 1990 with 24K miles and about a month later the cat plugged up. Mine was a slow decay over several days.....it ran progressively worse each day until Geo Metros would take me at stoplights! Luckily for me it was still under warranty and a new cat, EGR valve & tube were installed at the dealership. I have had 2 or 3 cats plug up on me since then......one thing you could do is remove or loosen up the EGR valve (or just take out the O2 sensor) and see what happens. It will be loud, but if the cat is plugged then it should run better (have more power) since the exhaust gas now has a better/more unrestricted place to go. Worth a shot.
But wouldn't the exhaust sound restricted. It is loud an boomy. Ironically, bystanders have told me it sounds good. I just thank them with a false smile. I would love it to be the cat converter. I'll loose it and the EGR system and never look back. It is true that the cat guts (nothing to do with tennis rackets of old) could suddenly fall loose like throwing a switch.
But wouldn't the exhaust sound restricted. It is loud an boomy. Ironically, bystanders have told me it sounds good. I just thank them with a false smile. I would love it to be the cat converter. I'll loose it and the EGR system and never look back. It is true that the cat guts (nothing to do with tennis rackets of old) could suddenly fall loose like throwing a switch.
It's possible that the cat plugged up and blew the gaskets out somewhere upstream (which is why it sounds "boomy"). Just throwing out ideas.....I hope you figure it out.
You can chuck the whole system, but you should get a re-programmed chip if you want to avoid throwing a few codes now and then, and perhaps a loss of efficiency. Many have commented that the engine runs no better without the EGR system...but perhaps they are tree-huggers like me who would prefer that you keep all that junk for the admittedly questionable good of the planet.
Sorry Neil. I didn't mean anything by the newbie comment. Twas just a segway into the welcome comment. Not surprisingly, I was pretty depressed when the timing chain replacement had no effect and this may have affected my tone. I am planning to cut a hole in the catalytic converter and gut it to eliminate that possibility now or an occurrence in the future. I can then patch the hole with a plate, high temp epoxy and some sheet metal screws. I don’t think the EGR is my problem but its future in the trash bin. Its proximity to the Ignition module and the coil has to be raising the temperature of these components. I think Fieros may be the only mid-engine cars with no side scoops to cool the engine compartment. There had to be arguments on this issue around the GM coffee pot. As for the tree hugging, I can sleep at night knowing that this car is one in billions. At least I live in the barbarous state of Louisiana where emissions are not tested. They do test the gas cap strangely. An aside: Years ago I had an Austin Healey 3000. I removed the bumper and bolted them back on once a year to get my inspection sticker. If I had a Ford GT, I’d likely do the same thing with at ugly rear bumper. It is not a part of the body so it’s as if Ford wanted you to remove it. It’ll be this evening probably before I neuter the catalytic converter. I’ll let y’all know what happens.
Took a few days to get to it but here's what happened. I cut a hole about 1" x 4" in the bottom of the catalytic converter hoping that the guts had come loose and all I had to do was pull the trash out and close the patient. It was empty. So I figured that its contents may have migrated down stream and clogged the muffler. So I closed the of the exhaust tips with duck tape and connected my leaf blower to the forth. I cranked it up expecting debris to come flying out of the hole I'd cut int the catalytic converter. Nothing did. I climbed under the car and a hurricane was coming from the newly cut hole. No blockage there.
The only thing it the catalytic converter is a tube with some small holes in it. Maybe that's all that was needed to meet the regulations in 1988.
The last time I dealt with a clogged up cat was on a mid 90's BMW and I remember (rightly or not) that the guts were a mixture of foil and fibrous cardboard like material that had disintegrated when the exhaust system became flooded with water. I pulled the debris out with a coat hanger and that was that.
When I start the Fiero now, it seems to rev more freely but the exhaust is so loud with the catalytic converter open that it may be just an illusion. I could go for a test drive as it is and that is tempting but that'd mean getting it off the jack stand only to put it right back up. Unless y'all have another suggestion or I have an epiphany, that's what I'll do.
The only thing it the catalytic converter is a tube with some small holes in it. Maybe that's all that was needed to meet the regulations in 1988.
The factory cat was twice as long as the replacement ones available today. It was a 3-way cat, meaning it had 3 honeycomb sections inside it (the catalyst). On my first Fiero the middle one melted and partially plugged the flow. Anyway, it sounds like your cat has been hollowed out. The question is, was it hollowed out before or after it was installed? If the guts of the cat broke apart and migrated to the muffler you will never get the pieces out......you will need a new muffler. This happened top me once and I did a post mortem on the muffler and it was unbelievable how packed that stuff was inside the muffler......there would have been no way to clear it out.
I suppose you need to figure out what happened to the guts. If they never existed (i.e. it was gutted before being put on the car) then you have an issue somewhere else. If the guts are in the muffler then you need a new muffler. Since it happened while you were driving I suspect that your muffler is clogged. With that hole in the cat your car should drive marginally better since the gasses have a place to go. Even though it is loud, drive it around the block and see if it behaves better than before.
I think you are getting very close to resolving your problem.
I took it for a drive to the local WinnDixie with the cat open and it was 5% better at best. That's about what I'd expect from taking a healthy muffler out of the system. That, combine with my blowing massive amounts of air back through the muffler, exiting the hole in the cat freely tells me that the problem lies elsewhere. FYI, my cat is short and the welding is consistent which the notion that someone replaced the original with a gutted one. When the event of sudden power loss suddenly occurred, I immediately looked for anything anomalous and saw that the four conductor electrical connector on the EGR control gismo had come unplugged and fallen between the harmonic balancer and the timing chain cover. It was all chewed up so, hoping that was the problem, I soldered the wires to their corresponding receptors and it made no difference. My next act will be to close up the hole in the cat and work on removing the EGR system to eliminate the possibility that it is maliciously envolved. I guess I am now eliminating possibilities rather than looking for the problem. It is analogous to seeking something lost. Instead of looking for it, I seek to demonstrate that it is nowhere to be found. To do that, no stone may be left unturned.
Have you checked all of your spark plugs? A bad plug will cause the engine to sound amiss and cause a lose of power. How about spark plug wires? Are they all good and connected ?
Wires are six months old. Power loss was sudden. Seems to be firing on all six. Changing the plugs is on my to do list but down the list of possible causes. Keep thinking.
I am no mechanic by no means but I would try the plugs, they are cheap. I know this is not the same but it could be related to your problem. I had a brand new outboard engine, 2 cyl, and the first trip I took it out it would lose power. Let the engine sit for a few minutes and it would be good again for a couple and then lose power. I changed the plugs and it worked fine every since, they were factory plugs that was the problem.
I will check the fuses. I assume there are in the same fuse box with the others. I have two sets of plugs. Bought a set. Lost them. Bought another set. Between the two maybe I can find a set. What is the plug gap for an 88 gt? I am dreading those front 3 plugs. I will try the method of pulling the top of the engine back with the dog bone disconnected. Most of my remaining day will be spent wasting time applying for jobs to comply with the demands of the unemployment claims. I have all day tomorrow and the weather is to be beautiful. I love the fall and spring.
OMG! I feel like the happiest idiot in the universe. At the suggestion of a blown fuse I stared thinking. When this happened I found the connector to the EGR module had fallen loose and was trashed. Fixing it solved nothing but I started thinking maybe that event BLEW A FUSE and fixing it with out replacing the fuse would be for naught. I pulled every fuse, finding one blown 5 amp fuse. I replaced it and checked the rest. All were fine so I stuck my key in the ignition and fired it up. Holy Cow! It's alive and I am so stupid. But I am smiling. I just have to screw the cover I have already fabricated to close the hole in the catalytic converter and I am good to go. What a long strange trip it's been.
I'm pretty proud that i diagnosed this within reading this in the first 5 seconds... I had the EXACT same thing happen to me... EXACT. TBI Fuse blown, firing on 3 cyl.
So Mitch, (or anyelse for that matter) what in the Fierck is the TBI? Throttle Body Injector maybe?
FYI: I couldn't resist going for an extended test drive with the catalytic converter open. It may be an illusion but it seems faster than it was before all of this happened. I would expect a little more power with less exhaust back pressure but it felt like more than I expected. I could make lovely power drifts with ease. My perception may have been altered by the sound track from The Dukes of Hazard vibrating the base of the drivers seat and thus the bottom of the driver who was all grins.
Hey gem all of the 4cyl Fieros are TBI ( throttle body injection) and have one big injector. Since Fieros use a lot of the same parts gm didn't bother changing the wording on the fuse box. The reason I knew about that pesky extra fuse is because I did a 4cyl to 2.8 swap. Oh and I also had one of those fuses blow and the car wouldn't go faster than 50 mph on the interstate! Glad its fixed now plug that hole in the cat and drive that thing!
OMG! I feel like the happiest idiot in the universe. At the suggestion of a blown fuse I stared thinking. When this happened I found the connector to the EGR module had fallen loose and was trashed. Fixing it solved nothing but I started thinking maybe that event BLEW A FUSE and fixing it with out replacing the fuse would be for naught. I pulled every fuse, finding one blown 5 amp fuse. I replaced it and checked the rest. All were fine so I stuck my key in the ignition and fired it up. Holy Cow! It's alive and I am so stupid. But I am smiling. I just have to screw the cover I have already fabricated to close the hole in the catalytic converter and I am good to go. What a long strange trip it's been.
Awesome!!! Congrats on finding the problem!! Good to hear it'll be back on the road soon. Are you leaving the exhaust as is, or replacing the cat and the muffler?
You are kind of a newbie. Welcome to the adventure.
...that's ok...still loved your promiscuous geese comment 
