H.O. Tps adjustment

I was wondering if someone could tell me how to adjust the Tps on an HO engine. I searched and found a ton of info on Renix engines but I don't have the same connectors as the Renix guys do so I wanted to make sure I was doing it right. I have been fighting a problem with it not running and today I discovered if I unplug the TPS it will start and run and rev the for first time in two months. So I thought maybe it was out of adjustment. So if someone could tell me how to do this it would be great.:explosion

The TPS on an HO engine is not adjustable.It can be checked with a DRB scan tool. With a digital volt meter--
Or with key on,center terminal wire,throttle closed->200 millivolts
At WOT-voltage must be less than 4.8 volts.
Output voltage should increase gradually as throttle plate is opened from idle to WOT.

Wayne

That would explain why I couldn't figure out how to adjust it. Does it probably mean it is bad since it runs fine with it unplugged, just a little hesitation when I give it gas but when I plug it in it dies.

2jeepdrivers said:

That would explain why I couldn't figure out how to adjust it. Does it probably mean it is bad since it runs fine with it unplugged, just a little hesitation when I give it gas but when I plug it in it dies.

Click to expand...

Sure sounds like a bad TPS.

Alright I replaced the Tps but even with the new one if I unplug it the Jeep will run but if I plug it in it dies. Does anybody have a wiring diagram for the TPS circuit I am starting to think it is a wiring problem, all of my grounds I recently cleaned and replaced the one on the passenger side of the block. If anyone has any input feel free to chime in I am out of ideas. I have all new ignition components getting 31psi at the fuel rail and 39psi with the regulator hooked and unhooked so I am right in spec, I have good compression ( don't remember for sure what it is I checked it about a month ago) new cps, new tps, new idle air control, and a throttle body I just cleaned every orifice in. Also I have tried a couple of different map sensors.:dunno:

I am looking at 91 and up on a Hayne's wiring diagram. It looks like the MAP and TPS get 5 volts from the same ECU wire. I would get your volt ohm meter out, and check the input voltage (power on, engine off) to the MAP and TPS, with the TPS disconnected, and with it connected. I suspect you are not getting enough voltage to the TPS, or maybe even the MAP & TPS. IF the input voltage is say 4.7 to 5 volts, then it may be the TPS return wire which I think is org/Dk Blu., Blk/Lt Blu should be the ground wire. Vio/Wht to the TPS and MAP should be a shared 5 volt input from the ECU/PCM.

If the ECU/PCM is only seeing say 0.2 volts or less at idle is too low for the engine to run. Such a low voltage could be caused by a bad TPS (you tried that already) a voltage loss going into the TPS from the ECU input wire, or a voltage loss in the wire going back to the ECU/PCM from the TPS. Either way you are looking for a bad connection, bad wire, or bad ECU/PCM output voltage, indicating a possibly bad computer. Bad wire or bad connector is most likely starting the TPS connector or the 5 volt feed wire splice in the harness between the TPS amd MAP sensor. Check the input to the MAP and the TPS. If you have 5 volts at the MAP and not at the TPS it is a bad splice in the harness.