krystar

i put the FQS to #3 to try to lean it out. as far as I know, early DME's can't be chipped...right?

i ran a compression check long time ago after headgasket and valve repair. it was fine back then and i have no reason to believe anything is wrong there.

krystar

yea it could be FPR stuck in high. is that fixable? or just get a new one?

at WOT, AF reads about 13.4-13.6 area so pretty decent

944Ross

I thought position 0 on the FQS was baseline, maybe not for your car?
http://members.rennlist.com/951_racerx/FQS-adjust.html

In practice there doesn't seem to be a way to rebuild a FPR. I "tested" mine by sticking an air gun nozzle into the inlet with air regulated down to 35 psi, at which it was closed. I gradually raised it and at about 45 (~ 3 bar) it was opening. A fuel pressure gauge and vacuum pump would be the best way to test.

krystar

yea position 0 is baseline. i moved to 3 cause it was in the 11's while cruising.

krystar

well FPR looks good. hooked up a fuel gauge. 30psi at warm idle. unplugged the vacuum line going to the FPR and FPD. 38psi. i don't think it's leaky injector. after I turn off the car, the fuel pressure starts rising to 40psi.

how to check that the universal o2 sensor is doing its job? which wire is the o2 sensor on the DME plug? I can try to tap it and check that it has a signal at the plug.

944Ross

Tap it in the engine compartment, it's easier. Keep in mind that the sensor draws air down the wires to the ceramic element. You didn't solder in the univ. O2 wires, did you?

krystar

naw it's just crimped.

krystar

bump....any more ideas?

944Ross

Did you try returning the FQS to 0?

Any chance the cat conv is plugged?

krystar

what cat.....

yea i'll put it back to 0 to try it out....but i expect it to go back into 11's

krystar

interesting discovery....I watched my wideband AF during startup. upon initial startup, I actually idle lean in the 15's (i made adjustment to the idle AF mixture screw to lean it out). then as the engine warms up, it slowly runs richer and richer until it settles at mid 13's.

if it is the o2 sensor circuit, is there a way to bypass it and trick it to run in open loop and just adjust fuel trim manually?

944Ross

Auxiliary air valve failure? I don't understand their function totally, but it could be stuck in one position.

krystar

whoah....finally got around to testing the o2 sensor. something's def wrong. off my digital multimeter, i'm only registering a 1.8mv off the sensor lead. maybe these universal o2 sensors don't work that good after all.

V2Rocket

try an O2 sensor specified for the car and see if it works, undo the battery, set the DME back to original FQS position, hook up the battery and then see what happens.

Calmchaos

How did you test the O2 sensor.
Did you heat it up? It should be pretty freakin hot when you test it. Then check the sensor by connecting the multimeter to a ground (I used the negative end of the battery) and the sensor lead.

It should read more than 2mV. I get 2mV when I connect my multimeter to my tongue.