88 IROC engine issue -- Help!
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Junior Member
Joined: Apr 2009
Posts: 9
Likes: 0
From: NJ
Car: 88 Iroc-Z
Engine: 5.7 TPI
88 IROC engine issue -- Help!
I am hoping some one here can help or offer some advice on my engine issue. I have and 88 Iroc with a 5.7 TPI. It is the original motor with just over 28 thousand miles. There have been no mods done to the car. I am the original owner and know all work that has been done to the car. Here is the problem:
The car will start with no trouble. Once running however it will backfire and chug. Most of the time in order to keep the engine running I have to play with the throttle to keep it going, sometimes that doesn’t even work. During this time the check engine light will be on. There are no codes stored. On occasion the car will start and run correctly. I might even be able to get it on the road and drive for a few miles before it begins again. Once under load on the road the car might be able to hit 30 MPH, all the while backfiring and chugging and shifting hard. Playing with the throttle some times will keep it going but most times it will just stall out. This can happen even while idling in the driveway. Once the car is warmed up a steady blast of hot air is coming out of the passenger side of the car, heating up the floor boards and rocker panels on the passenger side. It is also sucking up gas like crazy.
Some background on what I have done so far. The car was in storage for 10 years. Once taken out and put back on the road I had all fluids changed (oil, antifreeze, trans, differential, brake), along with a tune up. New plugs and wires, new battery cables, new alternator, and new mass air flow sensor. That was 2 years ago. The car was running fine but was down on power a little. Last year it had a coolant leak from the intake manifold gasket. Leaking out not into the engine. Had all gaskets replaced and threw a new thermostat in at the same time. The distributor was also rebuilt because it was rusted. Also replaced the ECM because the check light would come on, again no codes were stored. The car ran fine for 250 miles before the above started happening. Was told maybe the cat was clogged. I have since gutted the cat. No change. Also replaced the temp sensor. There are no leaks anywhere. The exhaust system is original and also not leaking or rusted. My next step is to try Sea foaming the engine to see if that will help at all then replace the fuel pressure regulator.
Sorry this post is so long but I wanted to pack as much info as I could. Has anyone ever had a similar issue or run across it? Any advice would be greatly appreciated.
The car will start with no trouble. Once running however it will backfire and chug. Most of the time in order to keep the engine running I have to play with the throttle to keep it going, sometimes that doesn’t even work. During this time the check engine light will be on. There are no codes stored. On occasion the car will start and run correctly. I might even be able to get it on the road and drive for a few miles before it begins again. Once under load on the road the car might be able to hit 30 MPH, all the while backfiring and chugging and shifting hard. Playing with the throttle some times will keep it going but most times it will just stall out. This can happen even while idling in the driveway. Once the car is warmed up a steady blast of hot air is coming out of the passenger side of the car, heating up the floor boards and rocker panels on the passenger side. It is also sucking up gas like crazy.
Some background on what I have done so far. The car was in storage for 10 years. Once taken out and put back on the road I had all fluids changed (oil, antifreeze, trans, differential, brake), along with a tune up. New plugs and wires, new battery cables, new alternator, and new mass air flow sensor. That was 2 years ago. The car was running fine but was down on power a little. Last year it had a coolant leak from the intake manifold gasket. Leaking out not into the engine. Had all gaskets replaced and threw a new thermostat in at the same time. The distributor was also rebuilt because it was rusted. Also replaced the ECM because the check light would come on, again no codes were stored. The car ran fine for 250 miles before the above started happening. Was told maybe the cat was clogged. I have since gutted the cat. No change. Also replaced the temp sensor. There are no leaks anywhere. The exhaust system is original and also not leaking or rusted. My next step is to try Sea foaming the engine to see if that will help at all then replace the fuel pressure regulator.
Sorry this post is so long but I wanted to pack as much info as I could. Has anyone ever had a similar issue or run across it? Any advice would be greatly appreciated.
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Joined: Jul 1999
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From: Everett, MA . USA
Car: 89 FORMULA FIREBIRD, 86 CHEVY CAMARO
Engine: L98, LB9 RESPECTIVLY
Transmission: 700 R4 (BOTH)
Re: 88 IROC engine issue -- Help!
unplug the maf sensor, see how it runs. the relays could be bad
Thread Starter
Junior Member
Joined: Apr 2009
Posts: 9
Likes: 0
From: NJ
Car: 88 Iroc-Z
Engine: 5.7 TPI
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