when sitting at a red light or just idleing my truck tries to die. it does die alot and sometime it doesnt. the previous owner said it might be the tps sensor. no check engine light or anything. when it doesnt die it idles at 1k and runs smooth. it has 274k mi if that helps. what do yall think it could be. and yes i did search. thnks!

 

anyone i need help

 

Hows your plugs, wires, rotor, cap? Checked for vacumn leaks? Broken vacumn hoses? Throttle body clean? Both boots leading to throttle body have any splits? Air filter clean? PCV valve clean, hose OK. Timing?

 

what does it do when the tps goes bad?

 

How about some details on the engine/vehicle?

The TPS doesn't really control anything at idle. Idle problems are usually caused by vacuum leaks, electrical problems, etc.

 

well its a 90 model 3.0 pickup. it has 274k mi. it runs pretty good. sometimes at idle it idles about 1k and runs smooth and then sometimes it starts to drop rpm's and wants to die. it does die alot but if the rpm's drop and it doesnt die. it sits there and idles horriably. like its got a big freaking cam in it. but i can tap the gas and it smooths out and. so i dont think it is a fuel problem. no check engine lights or nothing. idk. i wish i could get out and leave it running w/o worring if its going to stay running.

 

Check your butterfly valve in the TB. Sometimes gunk builds up around it and holds it open. That's where you may have set the idle. Then it will close up like it's supposed to once in a while & you'll let your low lumpy idle.

 

so u dont think its the tps. i was going to clean everything real good anyway. what about bumping up the idle up a lil

 

I think there are other things to look at before you guess TPS. Get some Valvoline Throttle Body Cleaner (or equivalent, but it works great) and clean the TB out good, REMOVE THE PLUGS & pump the excess out before you start the engine over to avoid hydro locking it and blowing a HG or bending a rod.