jffsmuffn3

13B rebuild @ 1500 miles ago, street port, no cats, header and 2 mufflers running fine then the other day it seems to have lost power and dies after it warms up and it is almost impossible to start until it cools off. then starts and runs fine till it re-warms. No vacuum leaks aws,bac ,wts,iat,all check out. TPS is showing high resistance reading on closed test of narrow and full range at about 3.3 ohms, spec is .08-1.5 ohms TPS reads corret to spec on open throttle, can a TPS cause this loss of idle,sluggish performance and hard or no start at warm motor condition? Somebody in the KNOW help me out please. THX, JB

RotaryRocket88

iTrader: (7)

First off, you should be posting what year / model you're talking about. S4 or S5? NA or turbo?

I'm going to assume S5 since you mentioned a dual plunger TPS. You should retest the TPS. There will be FOUR different resistance values, yet you only listed one. Go here to get some better testing info: http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1

The TPS can cause both idle and low throttle problems, so if has gaps in the stroke or generally wrong values, I'd replace it. Make sure you test it when the motor is warm and the key is in the 'ON' position. It doesn't have to be running.

More to the point, I would be testing the compression on the motor. Classic symptoms of low compression are hard starting, loss of power and poor idle.

Does it run ok when cold? Can you smooth out the warm idle by pressing the gas pedal?

wink1100

I agree, TPS has it's flaws. Specially after a lil bit of intake work. Seeing how most OEM used products used after modding use OEM spec mechanical parts to work properely.