1990 244DL.

I changed the FPR and main pump about 1 year ago. I get the check engine light now with a 232 and 113 code after a short period of idleing. After checking the o2 sensor (also changed within the past year) I get around .585 volts with the key in position II. Then, after starting the car the reading stay pretty constant around .25 - .35. What parts could cause this low reading? If I artificully creat a vacuum loss by creating an air leak on the intake side, the reading shoots up to .8 to .9. Thanks, I'm stumped.

A 1990 is one of those years that has what I refer to as "oh-yee-evil-fuel-computer", and this is one of the ways that it dies...either it loses ground, or it makes your car run full-ass rich.

Other sensors that are possible culprits are:

the coolant temp sensor
the air mass meter

Yes, a leaking injector could cause a problem, as noted in the previous post, but I have NEVER had that be the case on a 240 LH car. That's not to say that there won't be a first time....

Chris

Thanks - I read something like that in the FAQ - I'm going to get another ECU and swap it out - I'll let you know what happens.

try this:

pull your fuel rail off carefully with the injectors attached. place a rag over the port holes between the port holes and the injectors. hold them up, have a helper turn the car on, but not start it. your injectors should hold fuel without leaking.

what you are doing is energizing the fuel system so the injectors are ready to 'fire' so to speak. JUST DONT START THE CAR!! if you notice one of them dripping at all, it is a leaking injector and could very well be causing your rich running problem.

istallation is reverse of removal.

good luck
Chuck in mpls.
--
'87 BMW 325e 190K (used to feed a '84 245, '88 244, '84 244, '85 744)

Nice tip - as soon as it's not cold enough to freeze fire out there in my garage - I'll do it!