3.0 very high idle/revving

[Squarewheels287]

Got a 1997, 3.0 manual trans. Finally got it road worthy. Got a tank of fresh gas through it now. Recently gave it the old Italian tune up and ever since then it revs itself to around 3500rpm. Can't see any obvious vacuum leaks. Sprayed some carb cleaner around the intake and lines, no change. Throttle linkage works and throttle plate is closed. I unplugged the IAC and no change. Would the IAC allow it to rev that high?

 

[lil_Blue_Ford]

IAC, if stuck wide open, could possibly. Unplugging it won’t change if it’s stuck. Sometimes tapping on the IAC with a wrench or something will free it up enough to tell you if that’s the problem.

A bad throttle position sensor will do that to you too. You can check the electrical values with a multi-meter but I don’t know the correct values and wires to check offhand.

Start there and report back?

 

[SenorNoob]

Maybe if it were stuck open...

You can take it off and check that. The disc between the 2 holes will be off center if it's stuck open. I'd probably take quick look then hit with plenty of cleaner while it's off and try to work it some. IDK if that will be possible with the motor on it.

 

[Squarewheels287]

So naturally I went to test a few things this evening, and it fired right up and idled perfectly, revved it up and it went back to idling just fine. I guess I'll keep an eye on it and take note of the conditions if it acts up again.

 

[lil_Blue_Ford]

So naturally I went to test a few things this evening, and it fired right up and idled perfectly, revved it up and it went back to idling just fine. I guess I'll keep an eye on it and take note of the conditions if it acts up again.

Maybe go ahead and pull the IAC and clean it out with some carb cleaner before a little spritzer of spray lube. Maybe it’s just sticking

 

[Squarewheels287]

Figured I'd post a small update, it finally acted up again. Found the IAC to be hanging open. Attempted to clean it with no change, new one solved the issue.

 

[Terrys87]

Thanks for letting us know the fix. It could help someone else that could have same problem as well.