Idle to redline

[nlzn]

So after a full head rebuild i started the car today.. first key turn it started and decided it wanted to rev to redline (i turned it off before it got there).

I checked to make sure the throttle plate wasnt open and it was fully shut, started it up and did it again.

I know I torqued down the intake manifold but thats the only thing I can think of, that there has to be a leak on the intake manifold side of the motor pulling in extra air. I guess I'm going to check the torque on the bolts tomorrow again.

Anyone else have any suggestions? (im going to check the voltages on the TPS as well tomorrow via the logger)

 

[gob4sho89]

After my 6bolt swap, the same thing happened. I started it up again, i let it go all the way up to 6.5k, then fell to idle and ran normally......

 

[Jeff99GS]

So after a full head rebuild i started the car today.. first key turn it started and decided it wanted to rev to redline (i turned it off before it got there).

I checked to make sure the throttle plate wasnt open and it was fully shut, started it up and did it again.

I know I torqued down the intake manifold but thats the only thing I can think of, that there has to be a leak on the intake manifold side of the motor pulling in extra air. I guess I'm going to check the torque on the bolts tomorrow again.

Anyone else have any suggestions? (im going to check the voltages on the TPS as well tomorrow via the logger)

Boost leak test from the throttle body with the throttle blade open. This will check for leaks in the intake manifold like gaskets, injector seals, Vaccum lines and that brake booster hose.

 

[Colt4G63 also]

Make sure your ISC is plugged in and your brake booster hose in plugged in.

 

[spawn87]

well it can also be your iddle speed sendor or the screw on the top side of your TB is dialed all the way in

 

[nlzn]

Make sure your ISC is plugged in and your brake booster hose in plugged in.

Should have mentioned I aready checked the ISC and the brake booster was such a bi*** to connect for me I dont even need to check it.

 

[toofast82]

I had that happen and it was the throttle cable, not where it mounts but where it ran by the rail

 

[DSM-sagacious]

+1 on the boost leak test.

 

[nlzn]

I had that happen and it was the throttle cable, not where it mounts but where it ran by the rail

Cable wasnt even hooked up the first time i started the car.

 

[->PrOjEcTGS<-]

Check the closed throttle sensor if that for some reason got screwed down it will keep the throttle plate from closing all the way. Also check the BISS, screw it in as far as you can and see if you still get the same problem. You're letting air in from somewhere!

 

[nlzn]

hmm the CTS is the little guy on the side of the throttle body that has a spade electrical connector right?
(if so it was never connected on my car even before all this work)

Here's a pic:

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[->PrOjEcTGS<-]

All it does is tell the ECU that the throttle plate is closed or open. But you can adjust the point at which the sensor actuates. If it's screwed in too far it will keep the throttle plate open. It's just something to check and verify that it's not holding your throttle open.

 

[nlzn]

All it does is tell the ECU that the throttle plate is closed or open. But you can adjust the point at which the sensor actuates. If it's screwed in too far it will keep the throttle plate open. It's just something to check and verify that it's not holding your throttle open.

No. Before I even posted this I made sure the throttle was shut (or damn close by eyeing it) with the elbow off.

 

[toofast82]

Sounds like it just wants to race! run and gun!

 

[nlzn]

Well I figured something would go wrong. After 1 month of being bare down to the block it started on the first key pull after the assembly.. I guess i just did it too good

 

[Jeff99GS]

Well I figured something would go wrong. After 1 month of being bare down to the block it started on the first key pull after the assembly.. I guess i just did it too good

YOU have to be leaking air into the mani after the Throttle body....thats the ONLY reason it would rev on its own. At least that's the only reason other than the things you have already checked.

Do a Boost leak test ASAP to be sure there is NOOO leaks on the injector seals.

 

[dsmfa9nutter]

Check every hose barb on the intake, check your injector seals (I had one of these get squished when I put the fuel rail/injectors back in, let in air), check tb gaskets, check intake manifold gasket.

 

[nlzn]

I can't get my boost leak tester on it until this weekend (left it in my parts graveyard ).

I reset the throttle body today, read the voltages on the TPS etc.. I'll re-seat the fuel rail when I get home to make sure a seal didn't get pinched.

Only thing I'm confident in is the intake manifold.. i torqued it down to spec outside of the car with a new gasket with clean mating surfaces.. it's not leaking unless its cracked.

 

[Jeff99GS]

Also check the PCV valve hose. It connects from the valve cover to the intake manifold.