Hunting Idle

[steveb]

I am running out of ideas so I thought I would see if anyone could point me in the right direction.

1985 Corvette
Problem: Idle swings from 400 to 900 rpm rapidly. Sometimes it gets to the point where the engine dies. This seems to be an intermittant problem as I can go for weeks with a nice even 700 rpm idle before the problem arises again. Lately, this problem has occured more often.

What I have tried: Cleaned the throttle body, new IAC valve, reset min air adjustment and tps voltage, checked for vacuum leaks.

Is there anything else that I can try? The car runs great when I am on the gas. If nothing else, cleaning the throttle body seems to have given it more zip.

Thanks in advance.

Steve

 

[gmjunkie]

Steve,have you checked the EGR valve for carbon,or a leaking pintail seat?? It will sure make one act that way!!!

PS How is the Burg anyway??I used to live there in the Mid 70's!! Had a Shop out on N Henderson St in the High Rent district!! Still have allot of friends there,do they still play Plunger Tag and Follow the Leader on main street on Saturday night??

The most Crazy and Fun years of my Life!!!

 

[steveb]

Great idea. I have not looked into that yet. Thanks for the advise.

The Burg has changed a little. Most of the manufacturing has gone away. Henderson St has seen some growth. The one thing that hasn't changed is the trains. Hard to make it from one side of town to the other without getting stopped by a train.

Thanks again and I will check out that EGR valve.

Steve

Steve,have you checked the EGR valve for carbon,or a leaking pintail seat?? It will sure make one act that way!!!

PS How is the Burg anyway??I used to live there in the Mid 70's!! Had a Shop out on N Henderson St in the High Rent district!! Still have allot of friends there,do they still play Plunger Tag and Follow the Leader on main street on Saturday night??

The most Crazy and Fun years of my Life!!!

 

[gmjunkie]

Great idea. I have not looked into that yet. Thanks for the advise.

The Burg has changed a little. Most of the manufacturing has gone away. Henderson St has seen some growth. The one thing that hasn't changed is the trains. Hard to make it from one side of town to the other without getting stopped by a train.

Thanks again and I will check out that EGR valve.

Steve

Yeah,The Trains!!Santa Fe and Burlington Northern "The trail of the Snail"!!

 

[WhalePirot]

Steve,have you checked the EGR valve f?? It will sure make one act that way!!!

Glad I read this, as the 'pros' who redid my engine left the EGR control solenoid lying on the valve cover, and connected one vacuum port to the other.ad
So, now I know why the idle is so erratic.

Junk UR gold , pal.

 

[gmjunkie]

Junk UR gold , pal.

Thanks Dude,I've never been associated with Gold before, most people around here refer to me as Heavily Chromed!!!

 

[WhalePirot]

Wow, pal. You crammed so much knowledge up there that your hair could not keep up!

 

[John '85]

I had the same problem with my '85. The PCV valve was half of the problem, I just increased the idle on my throttle body to 700 (during a time when it was acting up) and that seems to have fixed the problem.

 

[steveb]

Finally have had some decent weather to get at the egr valve. It did look carboned up pretty bad so I just went ahead and replaced it. That seems to have done the trick. It ran great today. Thanks for the tip Junk!

--sb--