First Start 3K rpm.

[991gts6s]

Hey Guys.
I had my 77 930 engine out and tuned up and clean it up very nice

I installed the engine this weekend and started right up ...
The ilde is very high ...3000 rpm,. I cannnot bring it down,, 4adjusting the idle screw does nothing..

I checked and re checked all hoses and clamps

tested the Aux Air it closed fully with 12V and opened fully in freezer.

I was thinking it Must be the Idle decel valve? the round gold thingy ?
Will that shoot the RPM to 3K ?

thanks for any advise

[RarlyL8]

Check the throttle rod at the transmission, could have been bent during engine drop or install.

[Jim2]

You certain that the line to the brake booster is connected onto your intake manifold?

[16Volt]

Originally Posted by RarlyL8

Check the throttle rod at the transmission, could have been bent during engine drop or install.

I had a similar issue - the throttle rod was binding thus keeping the throttle open.

[infraredcalvin]

Check pedal bushings, just had that issue on mine.
Also if you have a hand throttle, check the lever and the bushing

[991gts6s]

Yes I checked the throttle rods..
I even disconnected it on the trans so it would be free. no diffence.. 3K rpm

Would a stuck recirculation valve make a high RPM? i did install the two new gaskets in there

[RarlyL8]

If it's not the throttle then you have an open air leak somewhere. Identify which throttle bypass devices you have and render them inoperable one at a time by pinching or plugging the vacuum line.

[991gts6s]

Ended Up being a crack in the U tube caused by the hose clamp couldnt see is under the cloth but once i removed it , it was totally noticeable..

What a pain in the ass to replace that hose it with the engine in .


ALL fixed ,, nice idle now..good revs and back down to 900rpm now.

thx