# Z24i Idle/throttle problem



## KylePanda (Dec 16, 2012)

It's been doing this since we got the truck. 
After we did the horribly blown head gasket, replaced the plugs, wires and cap.
It's still having issues staying running/reving up. 

We pulled the codes off the OBD It was the TPS, Got that replaced and the coils. It idles now but very poorly, and giving it gas it cuts out. 
It also runs A LOT better when it's cold. We also reset the ECU 

We think it could bve another sensor or something, But we have yet to check the OBD again. :wtf:

Video:


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## SciFiGuy (Oct 30, 2012)

That motor sounds like it has a hellava vacuum leak going. I would do the intake manifold gasket tests. If it blew the head gasket, there's a chance the intake gasket is leaking as well. 

Spray Gumout around the intake manifold and see if the engine increases in RPM's or smooths out temporarily. Or...spray soapy water around it and see if it cuts out, or makes bubbles or temporarily stops any hissing noise. It's definitely got a power loss problem or a vacuum leak, especially if your air pollution controls are good and it was running fine before the head gasket blew.

Sometimes if the intake gasket is bad, you can hear a hissing sound from the air leak. Or there will be a water leak. Failing that, check all your big hoses for leaks. Brake vacuum line, etc.

And there is also another possibility, not very pleasant: Perhaps the head gasket repair did not hold because the surface of the head was slightly warped due to overheating. Depends a lot on how hot the motor got before the gasket went. *One lesson I learned with aluminum heads:* The minute it begins to overheat, STOP. Don't try to make it to the next exit. Just stop right there and get it towed.

*Edit:* I watched the video several times. Have you checked the timing? Sounds like it's off a few degrees. If so, it's retarded. If the timing is good, then see the suggestions above. Sounds like it's making timing chain noise, too. Might be bad chain and needs a new tensioner. Maybe. This should have been done as a matter of course when they had the head off the engine. That clattering noise in the background on the video sounds a lot like chain noise. Sounds stupid but you can often isolate noise problems by cutting yourself a piece of broomstick about two feet long, sticking it up against possible engine problems, and then carefully holding the broomstick against your ear. It can tell you the difference sometimes between top end and bottom end knocks.


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