000 mv @idle,

[trading t/a]

Strange thing encountered recently. My o2's at idle are 000mv. Cant understand it. When under load it's fine, o2's cycle, cross count cycles. 16 psi on 93= 2* or less of knock(sometimes spikes more depending on how hard the transmission shifts).

Notice that when the o2's go to 000 it runs really rough, the tps doesn't react when I step on the gas, cross counts don't move until I hit the pedal more than half way. IAC stays at 0.........


Readings: INT-128, BLM's-135to145(varies slight driver's side exhaust leak), FP at 43psi static, IAC 0, o2's 000mv(under partial load readings cycle from 200-800mv)

I've tried 3 o2's (Delco, Bosch and Standard), 2 known good tps sensors, 3 known good ecm's, 2 chips(a turbo tweak and extender chip), checked all grounds.....

Any ideas?

Tomorrow if I can I'll through in some toulene(octane) to see if the little bit of knock goes away. Other than that I'm stumped....

Started after It accidently drank some 87 octane when I wasn't looking. No tell tale signs of any hg problems, gotta do a compression and leak down.......

 

[pacecarta]

if you're moving the pedal and the tps does not change (no change showing on the sm ) then the engine doesnt have a clue you've moved the pedal either , try a new tps

 

[19TTA89]

The strange thing about it is...We tried a new TPS...when you set the TPS Initially,It seems fine....# rise with pedal movement...But when the car is running,It seems to be very lazy,A stab on the gas to about 3k RPM's may only register .70 on the scanmaster...

 

[pacecarta]

the sm doesnt update that quick so it may not show how high it went , any one have a DS check it ?

if with key on engine off the tps registers as you slowly depress pedal (very slowly) and shows no flat spots , then i would assume its ok ,

and i assume you have a good O2 sender , an older or contaminated O2 may not register at idle because its too cold it needs to be at 600 when its a good sender and thats not easy to do if youve got a rich mix at idle with the cold days weve had

 

[Eric Stage I]

You might try temporarily blocking the PCV and see what happens. Sometimes they pass too much air at idle (even A/C Delco ones).

Regards,
Eric