hello i have a 1990 ford bronco

my problem is when i start the truck every runs fine or seems to but when put my foot on the gas i get no rpm's

it just stay's at idle not really sure but do you think its the tps at all and advice wouild be great thanks

 

Sounds like the TPS to me.

It is pretty easy to test, you should get .8-1 volt at idle and a linear rise to 5 volts at WOT.
Test it with the key on engine off.

 

ok i will try and take it off and test it that way also thanks for the quick reply

 

pull the intake tube off the throttle body and have some one watch the intake to make sure its openning when you press the throttle. i have a feeling your cable is either snapped or something not hooked up. the tps wouldnt keep the truck from reving, it doesnt have that kind of control.

 

+1 Im thinking somethings wrong/broke on the cable if you get no response.

 

Yep, broken accelerator cable is the most probable cause. Follow it from the pedal into the firewall and then into the throttle body. If it's clamped somewhere, or any of the plastic fittings seems broken, then you might have the cause. Do what Chem said, if the intake doesn't move when you step on the pedal the cable is definitely broke.

 

thanks for the reply's i have checked the cable it is fine i have taking up the slack so its doing good

i tested the tps and the max i seem to be getting is 0.30 when its at wot i will replace it and try that i'll keep you guys updated

thanks again

 

Jsut out of curiosity what would it do if the TPS was not working?
On my system if the TPS does not work it won't rev, it will just sit at idle.

 

It should still rev however, I believe the truck goes into closed loop mode and uses predetermined ratios for fuel.

 

ya the truck just sits at idle nothing happens when you step on the gas if the tps is bad and so would seem to be the case at the moment the computer cant get anything right it becomes in easy words dumb as a door nail.

 

Oh no, it will accelerate since you're opening the intake, but it won't run well because the engine will act like it's just iddling.

 

Ya that's the problem I seem to be getting I am going over the timing and. Vac lines also

 

Hmm, interesting, mine is a Holley after market and it would not rev, it ran like crap and obviously lean but no revs. The stock system may operate different however.

It was the TPS, replaced it and all was better.

 

The terms "Holley" and TPS in the same post defy logic to me... Or am I missing something and Holley has decided to wreak havoc on EFI systems by making EFI system components as well as they make carburetors?

 

I was wondering this as well, I know they make a EFI conversion for carbs but a TPS?....

Figured I was just out of "times" and Holley makes simple sensors now