Idle Speed Error

[garrinchilders]

Hi Guys My name is Garrin, Long time troll, first time poster.


I am having a High Idle (1300-1500), cold start idle is around 1900.
When I stop at a stop light for any amount of time longer than about 30 seconds, I get a Service Engine Soon Light. and The truck will not have a lot of power when it comes time to take off. When I do take off and reach about 20mph the light goes out. I manages to create the situation in my driveway and grab the code while the light was on. It said "Idle Speed Error" (Code 35 i think, or 30something). I figure its either a faulty or filthy IAC solenoid. But before I go spend the 35.00 on an IAC solenoid I thought I would ask if you guys thought that would cause these issues.....


1995 Chevy Tahoe
5.7 TBI 350
4x4 Auto

 

[AtomicHoe094]

sounds good to me. id buy it and see what happens, its only 35bucks and hopefully youll put it in too.

 

[haks310]

Could be a lot of things. Easiest ones: check for vaccum leaks, especially at the base of the throttle bod; check the PCV valve, make sure it does not need to be replaced and is on there good; check the coolant temp sensor, wiggle the wiring around and see if the idle changes. If all those check out then move onto the IAC, EGR and TPS, all these affect the idle.

 

[bass1775]

I agree, I recently had an idle issue when sitting still and it threw code P1115 (ECT) intermittent high voltage. I would have never guessed that. Replaced it, all is well.

 

[garrinchilders]

I have replaced:

IACS
EGR Valve
Throttle Position Sensor
Plugs
Wires
Cap
Rotor
Fuel Filter

Still has the 1200 RPM idle and a CEL after sitting at a traffic light for 30 seconds, saying Idle Speed Error.

I have NO vacuum leaks
I installed the IACS correctly (per instructions)
I installed the TPS correctly also.
Hell everything is installed correctly (FOR SURE)

What is causing this?

I have dumped 600.00 in parts for this truck that I have had 10 days and only put 367 miles on..... I am really getting frustrated.

 

[haks310]

Did you check and test the temperature sensor?

 

[garrinchilders]

Waiting on my buddy to get home he has 3 of them for a TBI 350 on his table.....

 

[jdawg901]

my cel comes on when im on the eway but it will go off when i turn the truck off then back on wont come on til i get back on the eway after about a couple of miles at about 60 to 65 .can i check the code when comes on without turning the truck off or does it have to be off if so it doesnt have the cel light on ive replaced all types off sensors except for the egr valve and tps no vac leaks either.

 

[garrinchilders]

LEAKING Throttle Body Gasket was the culprit of the high idle.... however it still stumbles and runs extremely rough under moderate to light throttle, when I let off the pedal it nearly dies.... what else?

 

[haks310]

LMAO one of the first things I listed.

Have you checked your fuel pressure?