Is this EGR related?

[Donster]

When the Phoenix gets to operation temperature, Anne says the CES light will come on when she stops, for an example, at a traffic light. As soon as she hits the gas, the light goes off again??
I'll drive it later to confirm, but does this symptom sound like an EGR problen? We suspect an issue somewhere with the EGR/EGR solenoid or vacuum lines anyways, as it idles rather high once it gets warm.
 
Any ideas?
 
\D

[Fierofool]

EGR codes are usually set at highway speeds.  This sounds like an idle speed issue if it's happening when the car's stopped then goes away when the throttle is opened.  Either TPS or IAC maybe?  Sometimes, I think if the timing is too far advanced, it can also cause an idle speed code to be set because the engine idles at a higher rpm than ECM set point. 

[Donster]

OK, just replaced the TPS and the IAC
RPMs/idle is now between 950-1000 when warm
Is that an acceptable value or still to high?
 
\D

[Duchess]

It's 1000 because I haven't seen it at 950 

[Donster]

 

[85GT]

when mine warms up idle drops to 750-850 rpm.....

[Fierofool]

I think recommended idle is 950 in Neutral with AC turned off and at operating temp.  I looked up the codes and the warning set should be 35 if the idle speed is +/- 50 rpm of the recommended rpm for 30 seconds, so in the range of 950-1000 should be good. 

The emissions tag on the deck lid doesn't give an rpm setting, but just says it's automatically controlled when the timing is set.  I think the generally accepted range is 950-1000 rpm for a V6. 

[Donster]

As of right now, she's running at about 950 - 1050 and that's where it's gonna stay unless something else breaks
 
thnx all
 
\D

[Donster]

Harry & Karin (HarryT) were at our house yesterday, and Harry listened to the Phoenix. He said he doesn't care what the tach says, to him it sounds like the engine is running around 850 RPMs. With the years of experience he has, I tend to believe him more than the tach.

But now my question is: If a tach is off by that much, how do you correct it or even confirm it's off?

\D

[Spartanzz]

there are tach filter fixes that help with the tach problems. Many GM cars in the 80's 70's and some early 90's cars (from what iv seen) have had this problem. I think radney sells the kit iv herd you can do it yourself pretty easily as long as you know how to solder correctly. I know there is a link somewhere that has the full instruction on how to do it yourself and ill see if i can find it for ya. I was looking into this as well cuz we always suspected my tach to be off as well.

[Fierofool]

A question.  Since the car's basically a hybrid of many years, is there any possibility that it has an instrument cluster from a 4 cylinder?  If so, the tach will read 50% higher than actual rpm due to 50% more cylinders.

[Donster]

Entire 120 MPH cluster with speedo and tach plus aux gauges was one of the first things I put in her car
 
\D

[jwrape]

I have the similar issues with my GT. Replaced the EGR tube with a newer one. Nothings leaking but my CEL comes on at Highway speeds.
My car sounds like it's idling around 900-1000 rpms but my Tach reads 1500. I know for sure, there is no way it's idling that high.
Also my tach reads about 5300rpms at 70 mph. Yea, my Tach is trashed. lOL!