So i got my head gasket fixed engines all put back together Car turns on! oh s*%^ full throttle without touching the gas, the throttle body is not being pulled, the gas peddle is not being pressed. When i turn it on the TB is closed not open yet somehow it still manages to go full throttle, i do not have the air filter or the hose that connects to it on though think that could be it? help please , P.S. i got a welder, and i can;t wait to use it :P, Let me tell you rebuilding this engine was a GREAT learning experience and A LOT cheaper than the dealership and another shop wanted to charge me the do all the work. All in all i'm happy, very glad that she lives again, just trying to figure out why she's fully throttling. Any help/advice would be greatly appreciated.

 

Sounds like you've got a huge vacuum leak or your iac valve is faulty

 

Yep.

I'd bet a leak somewhere between the TB and head. Tb to intake or intake to head.

 

how would i find out where this leak is? i don't believe it's from the TB to the head because that's on there tight i do not have the air filter box or the two hoses that connect to the TB or the front of the valve cover. hmmm any idea how to diagnose? not in the mood to blow my engine i fixed XD

 

Have you tried to pull any code? I say its its a sensor, iac or tps most likely

 

actually i haven't tried that yet, i think i'll work on that tomorrow though, since it's dark out and mosquitos are biting like fish on a great day

 

Our computers are pretty good at giving the right codes, im working on finding a short right now, and it told me which two circuits have the short

 

If it's running full-tilt with the throttle butterfly closed, you have an air leak. You have to have enough air flow for the engine to operate at that RPM, a sensor failure won't do it, not to that extent.

I'm also suspicious the IAC is stuck wide open, bypassing air around the throttle butterfly, or the manifold isn't seated properly.
Block off the throttle body air intake so no air gets in and crank again. If it still runs wide open, the leak is elsewhere. If it won't start when you block it, the IAC is leaking.
If the leak is elsewhere, check the intake manifold. Again. Sometimes it hangs up on the dowel locator pins and leaves a gap despite feeling nice and tight. Stick a mirror and light under there and take a look.

 

So i've checked everything and i can find no leaks, this is what happens though, finally found a video that pretty much describes it

 

massive vacuum leak ....is intake manifold tight againts head ?

 

two hoses that connect to throttle body cover the holes on throttle body then start .

 

So i am back. I checked the manifold and yes, there was a gap that gap is now fixed, a new gasket is on and no gaps visible, nor heard. The engine still revs high as hell when it is turned on. I now have the error codes P0505 and P0108 would these have anything to do with my engine deciding to want to rev like this?

 

P0505 is an idle air control malfunction, P0108 is Map sensor voltage too high. The first is a likely cause of your problem.
The second is probably a symptom of the IAC problem.. .MAP voltage is not what is expected for the actual throttle position.

 

so you'd recommend me switching the IAC out and hope that fixes the problem?

 

So i replaced it, and now the jeep goes to start for a second, then dies.