Hi having issues with my fiero having unstable revs at idle goes between (2500-2000) and while driving it dies on high revs sometimes even low revs but always when the revs get high

had the same issue last year sometimes the revs could drop down to 0 then back up where it was.
chances the pick up coil and it was good for the rest of the summer.
now the issue is back any ideas of what to do?

know issues and what i done to my Fiero Formula Automatic

EGR-valve leaking (my idle is about 2000-2500 revs.. goes down to 1500 when it gets hot doesn't sounds like the revs are that high though) (code 32)
had electrical problems bad cables from the battery fixed those
previous owner made a home made manifold without cat (don't know how it effekts the revs) (currently might have some minor leaks)
installed fierostores accel super coil
heavy duty ignition wires from fierostore
new battery
new generator
180F thermostat
had the spark plugs replaced 3 years ago.

quick answer appreciated since this is my daily driver and currently only car i own.

You need to get that idle down to 1000. Have you changed the EGR tube? You can loosen the bolts under the intake and cover the hole with a thin strip of metal. If the idle goes down, the tube is leaking.

quote ..while driving it dies on high revs sometimes even low revs but always when the revs get high .

How old is the fuel filter? This is a symptom I had when my fuel filter was clogging up.
But your EGR leak could be your prob.

[This message has been edited by 2.5 (edited 03-20-2014).]

quote Originally posted by Gall757: You need to get that idle down to 1000. Have you changed the EGR tube? You can loosen the bolts under the intake and cover the hole with a thin strip of metal. If the idle goes down, the tube is leaking.

egr tube was chanced by previous owner in same time as the manifold had some leaks when i bough it but think all or at least most of them were fixed got the idle down a bit and more stable. gone over the vacuum lines with some start gas and saw the idle go down at the erg valve so thinking of replacing the valve. The revs doesn't sound like it's at 2500 and no one i asked to listen to it thinks it's at 2500. Not sure if the idle issue is related at all to it dying at all since i had issues with the idle since i got it and the other problem appeared in bringing of last summer and now again. and the high idle has been for more than 3 years and haven't really rushed fixing it since it sounded good and didn't seem like much of an issue

quote Originally posted by 2.5: How old is the fuel filter? This is a symptom I had when my fuel filter was clogging up. But your EGR leak could be your prob.

no idea guessing as old as the car

Fuel pressure could be an issue. The V6 should be about 40 lbs and the I4 is about 12 lbs. The pump may be weak or a bad filter....

A high idle is a separate problem, and will affect overall performance. You can disconnect vacuum lines one by one and cover the open hole to see if the idle goes down. The tachometer may not be accurate, but it should not be that far off.

quote Originally posted by Robin_l: no idea guessing as old as the car

As a regular maintinence item that could be the dying problem I'd put a new filter in.