My 88 duke has become increasingly hard to start. Tonight after work, it developed a new phase. When it finally does start, it only runs for a minute or two, and then shuts off abruptly, like someone just turned off the key. It has fuel pressure -- fuel does not seem to be the problem. I'm thinking it's the ignition module. What do you guys think?

The question is does it have enough fuel pressure? Have you ever changed the fuel filter? Maybe your fuel pump itself is failing too. The ignition module is a fairly common part that fails too. Most seasoned Fiero owners carry a spare.

[This message has been edited by avengador1 (edited 01-11-2008).]

The '87 and '88 with DIS have a pretty tough IM. When I started having start and idle problems I did 4 things. Replaced TPS, CTS, thermostat, and rebuilt the throttle body with an Autozone kit ( 96-626B). The car idles very well now, cold or warm. On very cold days I have to crack the throttle just a tad until the car lights off. Warm starts are no problem. I think the throttle plate needs adjusting but haven't removed the factory seal on the adjusting screw until I can get a look at my IAC counts.

Hows the "Check engine light"? Are there any codes?

I guess the word that stands out to me is "abruptly". If it was fuel related I tend to think it would sputter to a stall. If it just shuts down then I am more inclined to suspect an electrical problem. It could be either a fuel DELIVERY fault like a bad relay or injector or it is an ignition issue like weak coil packs.

My first suggestion is to test the relays, if they are OK, then I would test the injector (I have my own injector tester but if you don't you can send them off for testing. New ones are PRICEY so don't buy if you don't have to). Then I would check the coil packs for proper voltage.

First switch the a/c relay to the pump position (not sure if coolant relay is same) if problem remains,have tools ready to crack fuel filter.turn key on listen to see if pump primes,if it does let sit for 3 to 5 minutes then open fuel filter connection if fuel shoot out,this is indicator that pump has good pressure.if a duke holds pressure for longer than 5 minutes you probably have a good pump,this is a good time to remove fuel filter and tap inlet on wood block to check contents this gives you also a partial guide as to the amount of trash in tank..or if problem is filter.. if fuel filter is filled with trash reinstall THIS filter to check amount of trash comming from tank later..Do not ever remove connection at T B I unless absolutely neccessary.. This connection will develope a leak if removed to many times(and you know how I know this) When engine stops and will not run have a known good spark plug ready to connect to #1 wire to check for spark.. eyeball ,diagnose, isolate. so as to repair only the problem and not replace parts,,you can also check each coil by checking a spark plug from each coil for spark intensity.. The 87 88 duke will run on one coil(2 cylinders) but is hard to start..Normally a duke will not die after start up and not start again, if one coil is good and the other is weak but working poorly.. when an engine dies if you squirt some quick start in the T B I , immediately, if there is spark & correct time it will fire.

[This message has been edited by uhlanstan (edited 01-12-2008).]

Update on my car. This morning, I went to my work, changed the ignition module, and after some trouble, got it started. I drove around the building -- no problems. I drove home (about 15 miles). It ran perfectly. I went in the house for 45 minutes. Then it was time to go the Fiero club meeting. It wouldn't start.
I know there is fuel pressure because I pulled the injector without doing anything to relieve the pressure. Got squirted with gas. I know the injector is working because it runs and drives perfectly when it does run.
Someone at the club meeting (I took my other Fiero) said to remove the ECM and re-do all the solder connections. Since my background is electronics, I think I'll try that.
And it hasn't turned on the check engine light at all. Maybe I'll check the codes anyway.
BTW, someone at the club meeting wanted to look at my duke because he has an earlier duke and wanted to see if it was possible to upgrade the belts to the single serpentine belt of the 87-88's. He couldn't check it because I took my V6. So does anyone know if it's possible?

Pat,

Check The Ogre's cave. The link is at the top of every Forum page.
He's got about as much 87-88 Duke experience as anyone here. That's where I got the "intermittant ECM" thing from.
Also be sure that all of the engine and ECM electrical connectors are securely plugged in.

quote Originally posted by Raydar: Pat, Check The Ogre's cave. The link is at the top of every Forum page. He's got about as much 87-88 Duke experience as anyone here. That's where I got the "intermittant ECM" thing from. Also be sure that all of the engine and ECM electrical connectors are securely plugged in.

All good advice. And speaking of ECM connectors, remember (IIRC) Capt Fiero's 4.9 problems? Very similar to what you are experiencing. The C203 connector under the ECM had come loose. Sometimes it ran great, sometimes nothing. Also, 3800Superfast had issues with a loose ECM ground giving him fits. That is also below the ECM on the center metal part. Here is a pic of the C203 and the solution to it not coming apart - a zip tie:

Update: The car seems to be working now. I bought a used ECM from Ebay, which originally came from an 87 Olds Cutlass Ciera 2.5. I put my ROM in it and put it in the car. It started right up. Let it warm up, tried several re-starts. Everything seemed fine, except the check engine light came on. I checked for codes and got 12 (OK). So I drove around a bit. It seemed fine. then I stopped and restarted it, and this time, no check engine light. Maybe it just had to learn that it was OK.
I'm going to drive it to work tomorrow. Wish me luck!

I had a similar problem. The ECM had a broken trace somewhere. I opened the ECM case, turned on the car, then pressed on the circuit board. It would cough and sputter as I bent the board, and would often stall out. That transparent rubbery coating they put on the board seems to shrink over time and start tearing the board apart. The only solution is to replace it with a refurbished unit. The old ones will all eventually have this problem..