stuck throttle

[somedaysoon]

 OK  first of all info, bb mopar, ls1 coil on plug, fuel inj, tps, iac, oxy sensor, and bs3. Took it out today jumped on it banged 2nd and throttle stuck wide open,  Disconnected tps restarted to wot. reconnected tps disconnected batt to try and reset ecu restarted to wot again.  Any suggestions as to why throttle is stuck. Oh and wilson manifolds throttle body and it is not stuck. Pete

[wally426ci]

Broken throttle return spring? is it hanging up on one of the linkages, the kickdown maybe? have a looksy..... 

[MEK-Dangerfield]

Broken throttle return spring? is it hanging up on one of the linkages, the kickdown maybe? have a looksy..... 

Wally,

  I think we are talking fuel injection here. It's outta my league, how about you?   


  Mike

[422STROKER]

That must have been a scary few seconds of Full throttle with twin turbochargers coming on in 2nd gear.

Maybe a quick check of resistance values will tell a tale on the tps, how long did you leave the battery disconnected?


Tom

[quagmire]

Unless you have electronic throttle control, which I highly doubt, you have a linkage or throttle body sticking.  The TPS is just an input sensor, and would not be able to keep you at WOT.  Even if the IAC was stuck completely open it would just idle higher than normal.  The throttle has to be stuck open somehow.

[somedaysoon]

 Throttle plate or butterfly is moving fine, and no stuck linkage or spring. Yes a little scary but i've got a toggle kill switch right on the dash,and with a manual trans the only real scary part was saving the motor, I've got a bobweight of about 2100 grams so it revs quick. I also posted on moparts and it has been suggested to unplug the iac and try it , then if that doesn't work pull iac out and plug the hole. Also check for vac leaks which I didn't have before. I'm going to try these as soon as I replace the toggle switch I broke, does that tell you how badly I panicked, It was a lighted plastic one didn't take much. But any suggestions I'll take cause I'm going to read them all and keep trying till it's fixed.  Thanks Pete

[wally426ci]

Wally,

  I think we are talking fuel injection here. It's outta my league, how about you?   


  Mike

Eh, woops. there were too many abreviations so I skipped to the end....  Yeah, Im clueless.... 

[GoodysGotaCuda]

Throttle plate or butterfly is moving fine, and no stuck linkage or spring. Yes a little scary but i've got a toggle kill switch right on the dash,and with a manual trans the only real scary part was saving the motor, I've got a bobweight of about 2100 grams so it revs quick. I also posted on moparts and it has been suggested to unplug the iac and try it , then if that doesn't work pull iac out and plug the hole. Also check for vac leaks which I didn't have before. I'm going to try these as soon as I replace the toggle switch I broke, does that tell you how badly I panicked, It was a lighted plastic one didn't take much. But any suggestions I'll take cause I'm going to read them all and keep trying till it's fixed.  Thanks Pete

As far as I'm concerned the IAC stuck at WIDE OPEN wouldn't cause the car to pull like that. Is this a throttle by wire, or throttle cable driven throttle body?

If it's cable driven carefully watch all the pivot points and the workings of the cable. Both at the pedal and anywhere else it may travel (at the firewall?). TPS probably wouldn't be strong enough to hold the throttle open if it seized up.

[somedaysoon]

 It's throttle by cable and all is functioning fine. I thought about boost, but I restarted It and it fired up at wot, by then any boost would have bled off. Pete

[GoodysGotaCuda]

It's throttle by cable and all is functioning fine. I thought about boost, but I restarted It and it fired up at wot, by then any boost would have bled off. Pete

It is sounding more like a IAC as far as the startup condition is going. But shouldn't be related to your stuck at wot after 2nd gear issue, unless your IAC is a huge one.

[Grancoupe]

If its not an open throttle and its not an Idle Air Control the next thing I would do is find the leak. there has to be one. I mean the motor can't fire up on nothing. I would try shutting off the ignition, blocking off the throttle and the IAC and cracnk the thing over. You have to be able the hear the air getting sucked into the motor from somewhere else. Could be a wide open crack in the bottom of the manifold? Or a seal split open somewhere along the intake tubes? I would ry to cancel out the intake sources to find where the motor is getting its air source.

[somedaysoon]

If its not an open throttle and its not an Idle Air Control the next thing I would do is find the leak. there has to be one. I mean the motor can't fire up on nothing. I would try shutting off the ignition, blocking off the throttle and the IAC and cracnk the thing over. You have to be able the hear the air getting sucked into the motor from somewhere else. Could be a wide open crack in the bottom of the manifold? Or a seal split open somewhere along the intake tubes? I would ry to cancel out the intake sources to find where the motor is getting its air source.

Dead on! I started looking after you posted and the back of my plenum at the top of the tunnel ram has split. Thanks Pete

[422STROKER]

Too much boost?


Blow off valves working?

Tom

Glad you found it.   

[somedaysoon]

Too much boost?


Blow off valves working?

Tom

Glad you found it.   

  Too much for sure, but yes makes me wonder. Don't know if it did it during shift or when I stepped back in after shift. So either blowoff or wastegate. But I will say this,  woohoo! This is going to be one fun ride, it is nasty. Pete

[black71]

wow nice suggestion and discovery!