what if I do not have my egr valve hooked up to the vaccum line, would this cause the car to shake at idle? I notice that my egr was not hooked up to any vaccum line. My car runs great when driving, but at idle it shakes like mad! Also there is a loud hissing sound coming from the front of TPI. I checked vaccum leaks, but none. Also could some one show a diagram of the vaccum lines for my car?

Thanks,
Rpettway
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1987 Pontiac Firebird Trans AM
305 Stock engine

If your engine is like my 86 TPI, a vacuum line runs from the EGR to a solenoid which is located at the thermostat housing on the driver's side. That solenoid has another vacuum line that runs to the underside of the throttle body.

That could be where your vacuum leak is coming from.

Hope this helps.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

Is the erg suppose to be closed at idle or open? How is the vaccum suppose to work with the egr valve?

Thanks,
Rpettway

EGR should be closed at idle, but yours could be stuck open. A solenoid is located between engine vacuum and the EGR valve, allowing the ECM to apply that vacuum to the valve when necessary.

I don't have one since the car was painted black over the summer!

Thanks,
Rpettway

RPett,

First, if you have a stock '87 TPI, you need to run the engine with the bellows attached to teh throttle body and air ducts, or you will set a DTC and operate in Backup Fuel mode ("Limp Home" mode). This alone could make the engine run poorly. If you are hearing the hissing sound at the throttle body with the bellows attached, you may have a hose off, loose or cracked throttle body, or leaks around the IAC stepper motor.

Second, Jethro is right on with the EGR operation. It should be fully closed at idle, and most of the time during operation, for that matter. If your's is open, you have a control or hose routing problem, or the valve has failed.

Third, I hope this helps:



And this is the EGR access method:


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Later,
Vader
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"I know how to solve your problem, but I can't tell
you since you might use the information illegally..."
Adobe Acrobat Reader 4.0

Thanks for the reply,but what do you mean by bellows? is it a tube or something?

Here are some pictures of my car!!

thanx vader... I needed one of those for my car... would you happen to have a wiring diagram for it to??? lol