My Fiero GT has been in and out of the mechanic shop and the problem still isnt fixed. The car runs excellent when cold, but horrible once it has been on for about 30mins or more. When it has warmed up, the oil pressure goes up and down a lot and my clutch pedal gets really lose. Just wondering if anyone that knows what else I can do???

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First thought, did they check the CTS and MAT sensors are working and reading right.
Would think the problem would show up sooner than 30 min. if they where the problem.

Next would be the ing. module in the Dist. getting flakey with heat.

quote Originally posted by Dodgerunner: First thought, did they check the CTS and MAT sensors are working and reading right. Would think the problem would show up sooner than 30 min. if they where the problem. Next would be the ing. module in the Dist. getting flakey with heat.

MAT sensors were all changed. I know if the fan isnt one then the car overheats fairly quickly.

I really need this issue fixed.

for the clutch. I would check the color of your fluid. bad fluid will often work ok until it gets hot. Or you could have air in the line, or a bad slave or master, I have had the exact same problem. for me it was a bad slave and fluid

[This message has been edited by FieroMonkey (edited 05-14-2007).]

Did the shop know which ones where the right ones to change.

You would be interested in the one in the air cleaner housing and the one the sticks out Horz from under the thermostat housing.

quote Originally posted by Dodgerunner: Did the shop know which ones where the right ones to change. You would be interested in the one in the air cleaner housing and the one the sticks out Horz from under the thermostat housing.

I have a custom air intake...do you think that sensor is what is screwing it up?

What did you do with the sensor? Is it laying over where it was at plugged in or is the plug just getting lonesone. I'm feeling kind of blue after looking at that picture...

You need to have a sensor plugged into the ecm otherwise it's going to think it's really cold air (high resistance from no sensor) or it should really set a SES light if it's not plugged in.

It is plugged in because when I unplug it, the Check Engine light comes on.

I've been having the same problem and I've tried a whole bunch of things and it hasn't fixed it.

I don't mean to hijack this thread or anything, but when I unplug this sensor and run my car I don't get a check engine light.... is this bad?

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Yes, having the MAT sensor unplugged or shorted should set a code under normal conditions. Have no idea what unmormal would be!

Have you checked your fuel pressure.

On you oil pressure changing does your idle hunt? That will easily cause the pressure change.

Also have you check fuel pressure.

Should get Winaldl to see what the sensors are doing. Its free software though best to have an old serial port laptop to run it.
http://winaldl.joby.se/

Build (or buy) an aldl cable. How are you for simple soldering?
http://couleefiero.tripod.com/ALDL.htm

Of course, it could be the Ignition Module as it tends to act up only when hot.

[This message has been edited by Hudini (edited 05-21-2007).]