1994 V-6 is idle surging. What causes this?

[caliskier]

Hi,

I have a 1994 V-6 3.0L that is idle surging. When I come to a stop the engine oscillates from normal idle to twice the rpm of idle. 2 seconds at a normal idle and 1 second at a high idle. Kinda like this…

_ _ _ _ _ _ _ *****_ _ _ _ _ _ _ *****_ _ _ _ _ _ _ ***** _ _ _ _ _ _ _

Anyone know what causes this and how to fix it?

Thanks

 

[Wicked_Sludge]

i'd start by cleaning the IAC solenoid.

another possibility is a bad TPS.

 

[du510]

How is your AC compressor? Low on fluid?

 

[caliskier]

Thanks guys, couple of questions, not down with the acronyms yet?

IAC = ?
TBS = ?
AC = Air Conditioning? Not using it, in Oklahoma very cold.

 

[Southern3.0]

IAC is Idle Air Control valve, it looks like this and will be on the intake plenum right by the throttle body.

To clean it, there's 2 bolts on the side of it that you take out and then undo the wire conector, then pull it straight off. Then look at the bottom of it theres gonna be 2 Dime sized hole that you spray out w/ carb cleaner. let it dry the reinstal it and see how she runs.

TPS is Throttle Position Sensor and it can look like any of these, on your truck it will probibly look like the one on the bottom right and will be on the throttle body opisite of the throttle linkage

And AC is Airconditioning

 

[du510]

Thanks guys, couple of questions, not down with the acronyms yet?

IAC = ?
TBS = ?
AC = Air Conditioning? Not using it, in Oklahoma very cold.

Yea - its air conditioning. But its on if you have the defrost on, etc. even if you arent having the AC blowing cold.

 

[caliskier]

Thanks guys I will check into these, starting by cleaning the IAC

 

[xr400xr50r]

Thanks guys I will check into these, starting by cleaning the IAC

i had the same problem...cleaned the IAC and couldn't get it to work any better...i replaced it (i wanna say it was about $55 at autozone) and it's been fine since. That was 120k miles ago
Good luck