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throttle sticking

Smittty9785

NAXJA Forum User
just replaced my TPS and had a shop fix cylinder 5 and 6 that were barley firing. Now seems like everytime i step on the gas from any stop or already in motion, the throttle gets stuck and revs up until i hit the gas pedal a couple times and it frees itself. any suggestions or anyone else ever have this problem. BTW its a 1990 automatic with the 4.0 I6. Thanks for the help.- Matt
 
did you adjust the tps to specs with a voltmeter?

check the throttle linkage for binding.

what did the shop fix to get 5 and 6 cylinder to fire?
 
Make sure the TPS was adjusted properly.

When it revs up, try pulling the gas pedal back with your toe. If it responds, then you know that it's a mechanical rather than electronic problem. Also, try revving it with the throttle body alone. If it always returns normally when you do that, it's another sign of linkage or cable issues.

Check the bell crank on the side of the engine for wear. That can cause intermittent binding when the bushing in it develops too much slop. Also make sure the pivot of the gas pedal is lubed and free. Spring return on the throttle body is weak on these, and one solution if you have binding is simply to put another spring in. On my old 87, the worn-out bell crank was permanently seized on, so I just took a long coil spring and ran it from the linkage on the throttle body back to some bracket on the valve cover (forget exact location now).
 
when it does get stuck, i try to lift pedal with my toe and it still sticks. had bad intake manifold gasket and that was why # 5 and 6 were not firing all the time. Im not sure if they adjusted TPS but i made sure to let them know that it was a brand new one and i had not done that yet. i asked for them to do it but it is not on the bill they gave me. Maybe they didnt charge me for it because it was just an adjustment. Should i take it back and make sure they adjust it?
 
PM Sent, but also check for anything that it might be binding with. It may be as simple as the cable was not reconnected properly or got bent hard and then they tried to bend it back straight but it didn't.
 
Hey Smitty how's the TB doing now? just checkin up to see if it was workin for ya.
 
Stihl029 said:
Hey Smitty how's the TB doing now? just checkin up to see if it was workin for ya.
havent got to it yet, last week when i took it for a 5 minute drive it started smoking everywhere. found out both my trans cooler lines had small pinholes in them squirting oil on my exhaust. im not replacing the lines and it is a pain in the butt to remove the old lines from the trans when the exhaust is 1" away. so working on that then im gonna work on the TPS. thanks for the concern though.
 
Does anyone have more details about the cable linkage from the gas pedal and the potential for that to get hung up on its way to the more solid linkage attached to the TB? When I rev my engine from under the hood, it snaps back to idle quickly and no problem, but the gas pedal is tough to push, and it releases semi-sporadically. After lubing the cable from the driver footwell and cleaning the TB, and lubing the linkage at the TB, it is better, but I still think it is binding somewhere between the pedal and the other side of the firewall. Any thoughts? Lube around the firewall in the engine bay? How do I loosen it up??
 
Also check the pivot on the accelerator pedal itself. You can pretty easily unhook the cable at both ends, and test for free movement within the sheath. It it's not binding, check the pedal, and then check that bell crank if it's a Renix setup. When the pivot on the bell crank started binding on my 87, the symptom was the same. An extra spring from the TB to a convenient point on the engine solved it.
 
thought I had High idle problems one time, turned out my factory spring was worn. From pedal to metal action. helper spring solved it. Make sure you cable isn't pinched
 
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