O2 sensor heater...what can affect it?

[Beej '86 325es]

I was screwing around with the car some more yesterday, testing sensor resistance levels all the way back at the DME, and all checked out.

However I noticed a leaky injector. I haven't determined if it's an O-ring (which just got replaced) or the rail itself though. I found fuel up on the metal neck that connects the main rail to the injector. I don't think it could spray up there, so I'm wondering if the rail itself has a problem there.

So, new theory...in open loop it may not be putting enough fuel in that cylinder, causing a lean condition, and MAYBE when it goes into closed loop the other cylinders' injectors are compensating and able to get the whole system to stochiometric 14.7:1?

...it may be a long shot, what do you think?

[Beej '86 325es]

I did some more testing tonight: start/re-start/sit and re-start.
I got some variable results tonight. Once I'd had the engine running for a total of about 12-15 minutes...

-If I turned it off and restarted immediately, I had O2 power right away.
-If I let the car sit for 5 minutes it would only take a few minutes.
-I then let it sit for 30 minutes it would take the full 9 minutes.

I have a theory...stay with me here... :)

I read today that the computer stays in open loop until it is 120-140 degrees. I'm wondering if mine is just taking a long time to warm up since my cooling system consists of:
-Stewart Racing water pump
-PWR 40mm aluminum radiator
-80 degree thermostat
-SPAL 16" fan (doesn't click on until it needs to though)

And possibly it may run a little lean in open loop because of the 1mm oversize valves and 3.5" MAF. But the custom tuning should account for any of that.

Thoughts?

[Beej '86 325es]

http://forums.bimmerforums.com/forum...postcount=2487
related maybe????

Interesting, but I did a quick search and the Euro 320i uses a different sensor than we do. We've got a Bosch.

BTW, I've been researching a lot on Bimmerforums also. :)

[lolcantturn]

http://forums.bimmerforums.com/forum/showpost.php?p=23773027&postcount=2487

related maybe????

[Beej '86 325es]

Whats the next step? seems like you've covered everything.

See my post #15 on trackjunkie's thread:

http://www.r3vlimited.com/board/showthread.php?t=238093

verify the O2 issue on your car, then report the facts! That's the only way to resolve it.

[lolcantturn]

Whats the next step? seems like you've covered everything.

[Beej '86 325es]

define excellent? lol

Touche...to spec per the Bentley ;) If I remember correctly I think 48 psi.

[328ijunkie]

define excellent? lol

[Beej '86 325es]

You checked fuel pressure? It takes 20 seconds

I checked it coming out of the fuel pump under the car and it showed excellent pressures.

[trackjunkie21]

Disconnect front fuel rail line. Attach a T to it. Run one end back to fuel rail and the other to a fuel pressure gauge. No cutting required.

ahh didn't even think of that, thanks!

[328ijunkie]

Disconnect front fuel rail line. Attach a T to it. Run one end back to fuel rail and the other to a fuel pressure gauge. No cutting required.

[trackjunkie21]

You checked fuel pressure? It takes 20 seconds

I may want to test this again and I don't want to cut any hoses, where should I tap into?

[328ijunkie]

You checked fuel pressure? It takes 20 seconds

[lolcantturn]

Reset my DME for 30 seconds and let it idle......no difference. still seems like its running lean. Blah I give up.

[Beej '86 325es]

I didn't have my VSS connected at all (pin 14) so I connected it today, let the car run for about 5 minutes and nothing, no improvement in anything. I have continuity too. Perhaps I should have reset the DME?

I've unhooked power to the car numerous times. In fact that used to be an S.O.P. whenever I was done with the car since I've got a crappy Optima battery that likes to die if I don't keep it charged. I've since installed a battery tender.