The EGR valve on my 88 V6 has been removed by the previous owner and the exhaust blank off, no problem here but not sure about the vacuum lines as the engine seems to run irratically at idle.

From the vacuum diagrams, I see that a line went from the switch mounted above the water pump to the EGR, on checking the switch the line is missing but nothing is blocking the connection to the switch. Could this be the cause?

Viewing the vacuum diagram I see the vaccum is actually created from the intake manifold. Should I remove the switch and blank off at the intake manifold or should I just blank off at the switch connection with some suitable?

Thanks

I think you are talking about the MAP sensor....which you should keep. If you cover the hole with your finger does the idle improve? It may run better if you re-install the EGR components, assuming the computer thinks you still have one.

edit....it seems like that would throw a code.....does your SES light work?

[This message has been edited by Gall757 (edited 04-10-2012).]

The EGR solenoid is the round assembly above the water pump. Kinda seems simple to me, plug the line and if the idle is better, you’ve found the problem. With that said, usually a small vacuum leak won’t cause a hunting idle but rather a rough one. Sometimes the ECM doesn’t get the IAC seated correctly so the idle will “hunt around” but this doesn’t usually happen every time the car is started.

Need:
A better description of what “erratic idle” is.
Year and engine

I have done a little research the switch is the EGR solenoid Fiero store Part # 68324

The SES is working no codes showing, so I assume the ECM was reprogrammed at the time.

The revs seem to drop and then rise almost like the engine is pulsing, it will stall occasionally when cold, not so much an issue when hot.

All vacuum lines are connected to the soleniod other than the one to EGR.

Not had a chance check yet as not been able to get back to the car to do any work.

Thanks

ALL ECMs are programmed to have the EGR off at idle.

plug the one that was going to the egr. any open vacuum line will afect the idle, usually making the idle high.