My 88 2.8 will start and run pretty decently. It will drive and be fine for about the first 15-20 minutes of driving. After about 20 min, the car will start dropping on its face then bucking at steady throttle. If you WOT it will stutter then take off. Sitting in park idle is good at about 800-900 RPM. in park once this starts a steady increase on the pedal will result in erratic raise in rpm. Also the tach will start to go nuts as well if held at any RPM over idle.
------------------ "HICCUPP" 1988 2.8 GT Ocelot SS exhaust
Originally posted by ChuckR: Also the tach will start to go nuts as well if held at any RPM over idle.
Ogre always wants you to remove the tach filter to rule it out. Something is changing when the component gets hot....so I am thinking it would be the pick-up coil or the ICM. The pick-up coil can be tested on the car.
There isnt a tach filter on it, so it will be more likely to have an erratic gauge, but it only happens after it has been running for a while and after the erratic throttle. I tested the coil it tests good but that was also at cold and not hot. The coil only has about 200 miles on it. They are cheap enough i will try replacing it again. I was thinking it was in the ignition myself but I wanted to see if anyone else knew what it could be from experience. That or somehow TPS once it is hot it is going bad, kind of has that feel to it when you have a bad TPS. Lurches about. Happened on a 90 degree day and on a 65 degree day so it is not climate related. But I agree that there is a thermal dynamic to this issue once the car is at 220 or higher. But since I do not have a tach filter on the coil and since it does go nuts with this issue I am leaning to coil or ICM. I only drive the car about a tank of gas a month or less. Mainly because I do not feel like it is dependable yet, only had it since July.
Good call, this is what I get for checking thread right before I go to bed. I was thinking ignition coil when I said I checked it with the ohmmeter... Even with the pick up it is cheap enough that just changing it out makes sense.
More on the behavior, when it starts to act up at a steady cruise it will start backfiring and stuttering. Again though car idles perfectly. just only on throttle is there issue, and only after about 20 min so once the car is up to full temp. I will try changing the pick up coil. Any other suggestions on causes?
Ok new season same problem.... I started it up for the first time this year, it ran good then when hot it sputters along. I know we have discussed a pick up coil possibility, but this feels just like it did right before I changed out the ignition coil. So i went to take off the one I have in it and it was burning hot. Could I possibly be experiencing heat soak on the ignition coil? it is mounted in the stock location,. However the previous owner had done an EGR delete so the EGR is no longer there nor the heat shield. the Coil seems to be only about an inch or 2 from the exhaust manifold. I did heat wrap the manifold but i dont think that is doing much. Should I attempt to relocate? Thank you in advance for any feedback. Also I have a used known good distributor I can put in I just havent yet.
Thank you, the whole system is removed and I believe it has been in the ECU as well. If my main goal was to keep this engine then I would put the money back into that aspect, however I am planning a swap. I just want to be able to enjoy the car until I have all the swap details ironed out and I have to pull the current engine.
I am down to ignition coil, pickup coil, ICM, or fuel pump for causing this issue. The Ignition coil is new but it could have gone bad again so I will replace that under warranty. If it continues to happen I will change the distributor out with a used known good, if it still continues I will drop the gas tank and replace the fuel pump. I tried relocating the ignition coil last night and it did not fix the problem. The only other thing I can think of is alternator since my voltage is fluctuating by turning on the turn signal. the AC fan, headlights. I am also replacing grounds and adding new ones for this same reason.
Replace the ICM with an AC Delco brand part. You can buy a tach filter from TFS or Rodney for piece of mind.
If you wanna go hog wild, replace the ignition coil at the same time. No harm there.
BTW, does this fiero have an old cat. convertor on it?
I personally found that running the fiero without a cat. convertor was the best mod you can do without having problems.
Also PO removed the cat so it is emission system free. The coil is mostly new. I will swap the distributor out with the known good. The one on it is the new star style the know good used is a stock style with the "ears". I guess I should just do it. I am a bit nervous swapping the dizzy since I dont want to wreck my timing. I have never messed with a dizzy like that before. I will also warranty the coil I just bought in case it is also bad again. The tach filter i am not that concerned with.