I'm just wondering. I have a 1988 4 cyl. automatic. I'm not sure if the ECM is the problem or if it is something else. It could possibly be a vaccuum problem. I've been having problems with the engine idling and have already replaced the IAC and the TPS.
What about plug wires. When mine idles funny its usually a bad/burnt plug wire. Even when I thought they were not that old one on the backside was burnt and leaking
sinoloa, Ed Parks at The Fiero Factory (256-420-5391)has Fiero ECM's for $50.That includes everything(ecm,calpak,and prom)ready to go. These are used but they work fine.I have purchased one from him and was very satisfied.Besides, if it didn't work, Ed would send you another one free(once you sent the other one back)
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05:17 PM
88formula Member
Posts: 2361 From: Worcester, MA Registered: Oct 1999
87-88 4cyl Auto Fiero is great for whacking the air cleaner against the trunk wall. This is a combination of it's single tranny mount and the soft OEM dog bone.
Whacking the air cleaner tends to scrag the gasket under the TBI. Too bad and it can ruin the TBI or crack the manifold.
Also check the elbo for the PCV vavle line, it's likely to leak. put a second small clamp on it where it attaches to the manifold. don't over tighten the clamp. the elbo is a soft part. not like fuel lines.
You also need to drive the car to warmup, then reset the ECM after you've hit at least 35 mph a few times. The ECM will be off after an IAC change.
If you haven't done so already, replace the plugs and wires. The DIS motors can be very crabby about this. DO NOT use Bosch or similar platinum tip plugs in the DIS motor.
[This message has been edited by theogre (edited 10-31-1999).]
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08:03 PM
sinoloa Member
Posts: 37 From: texas, U.S.A. Registered: Oct 1999
theogre: You must be a genius with the fiero. We just bought a set of Bosch platinum plugs and put it in. The ones we pulled out were Bosch platinums with a gap of 80,000. It doesn't act like its missing or misfiring in any of the cylindars. But, we did locate and spray some brake dust cleaner around the intake manifold in which we did get a change in the RPM and black smoke in the exhaust from around the center part of the intake manifold where it goes to the head (as if it were flooding). So we feel like your first suggestion will be our problem. Thank you for your help.
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10:26 PM
sinoloa Member
Posts: 37 From: texas, U.S.A. Registered: Oct 1999
To late..... some poor fool spent hours cleanning that mess up......
freaked when sprayed near the center of the manifold.... also check the EGR really good. In fact check that first.
look at the air cleaner and trunk wall for signs the've gotten intimate. If they have you have two options. Find a "type one" or "old style" dog bone and put in urethane bushings in at least one end or get the "ultimate dogbone" from Fiero store or someone else that makes such a thing.
If you put in the "ultimate" unit, or replace both ends of the old style unit with urethane you are going to dramatically increase the transmission of engine vibration to the body. You will however eliminate the air cleaner hitting the trunk.
[This message has been edited by theogre (edited 11-01-1999).]
will that EGR valve make the engine idle higher until it warms up? How can you tell if the EGR valve is shot? This sucker is nickle and diming me to death. I've done everything but set fire to it. I've sprayed break cleaner all around the intake manifold and TBI and all hoses and fittings and can't get any change of idle, so I know it can't be a vaccuum leak.
The engine is suposed to idle higher untill it warms up. the cold idle range is usually 1000-1500, but could be a bit higher depending on the weather.
check over the ECM temp sensor and the thermostat neck. If the sensor is covered in crud the thing will read slow. It might be slow from age and need replacing.
