Help with codes 63 and 31

[superhuaman]

I am having an intermittent check engine light on my 90 306. When the car has been in use for a while after warming up, the light will come on. The codes I pulled were 63, tps voltage below min, and 31, evp voltage below min. what i did tonight was, unplugged the tps, put some dielectric grease on the plug, replugged it, ran the koeo self test again, passed (except for 67). i started it up and the engine light promptly came on again. i really hope i dont have to replace my injector harness...ive already dielectric greased the black and white plugs on the back of the intake. do i have bad sensors? it only seems to do it when hot. also, i ran the test with the tps unplugged and it gave the same code. it seems like maybe i have intermittent reference 5 volts, but ONLY to those two sensors. it's friggin weird.

(was posted in tuning first, unfortunately)

 

[superhuaman]

bump

 

[jrichker]

bump

My original reply to your post in the tuner forum may be the only help you get. There aren't too many people that will diagnose codes and recommend repair proceedures here.

 

[superhuaman]

well today i went to adjust the idle speed and the tps voltage and i discovered several important things:

the tv cable was/is holding the throttle cracked
(so i set the idle speed properly with the cable unhooked, i will have to modify it tomorrow.)

the tps voltage is different when the engine is off and running because of charging voltage. (0.98 off, 1.03 running. 0.964 off, 0.98 running)

it runs a lot better now. the check engine light did come back on several times during a trip but went off a few seconds later i havent pulled codes yet.