Attn: Michael or Scott in the Apex area (or anyone else with a 93-95 525i)...

[billb]

Would either of you guys be "willing" to let me borrow your AFM for a few minutes? I'm trying to find out why my 525 goes through this wonky rich running thing, and I've tested/replaced everything but that. New FPR, new O2 sensor; checked and verified correct operation of ECT, IAT, TPS, CPS; all injectors firing (and clean!), all coils firing. I'm nearing wits' end...

I'm in the phone book, under Bass William, or shoot me an email. It's in my profile. I'm at work this morning (Saturday) until noon, then free from noon -4, and most of the day tomorrow (Sunday).

Thanks guys!

[Bill R.]

engine is warmed up?







Would either of you guys be "willing" to let me borrow your AFM for a few minutes? I'm trying to find out why my 525 goes through this wonky rich running thing, and I've tested/replaced everything but that. New FPR, new O2 sensor; checked and verified correct operation of ECT, IAT, TPS, CPS; all injectors firing (and clean!), all coils firing. I'm nearing wits' end...

I'm in the phone book, under Bass William, or shoot me an email. It's in my profile. I'm at work this morning (Saturday) until noon, then free from noon -4, and most of the day tomorrow (Sunday).

Thanks guys!

[bimmerd00d]

i have no idea where the apex area is, but i'd be more than willing to loan you mine if you were in dallas.

[billb]

engine is warmed up?

[billb]

engine is warmed up?

I pulled the cover off the connector and am backprobing the connections. Getting ~1V at idle, and it increases as engine speed goes up. Checking O2 sensor though at the DME, I am only seeing 0.45V...it's not changing, even when the idle is hunting up and down. Isn't 0.45V the midpoint for stoichiometric operation? I can't get it to run long enough for me to crawl under and backprobe the O2 sensor connection, but with the sensor out and using a propane torch, I was able to get it to go back and forth around the 0.45V point, all the way up to 1, down to almost 0. Hmmm, maybe that's where I need to look...if it's not fluctuating, it's not adjusting. Wonder if I've got some wonky wiring going to the DME from the O2 sensor?

[Bill R.]

sensor is up to temperature and working correctly the voltage fluctuations are pretty rapid.. about 3 to five times a second on cars that are adjusting correctly.... What happens if you disconnect the throttle position switch and then run the car? Not the maf just the throttle position switch









I pulled the cover off the connector and am backprobing the connections. Getting ~1V at idle, and it increases as engine speed goes up. Checking O2 sensor though at the DME, I am only seeing 0.45V...it's not changing, even when the idle is hunting up and down. Isn't 0.45V the midpoint for stoichiometric operation? I can't get it to run long enough for me to crawl under and backprobe the O2 sensor connection, but with the sensor out and using a propane torch, I was able to get it to go back and forth around the 0.45V point, all the way up to 1, down to almost 0. Hmmm, maybe that's where I need to look...if it's not fluctuating, it's not adjusting. Wonder if I've got some wonky wiring going to the DME from the O2 sensor?

[Steven G]

http://bimmer.roadfly.org/bmw/forums/e34/5802947-1.html
Bill
You might want to check this link, looks like a similar problem to yours except on a V8 engine (hope this might help you).
Steven G.

[billb]

sensor is up to temperature and working correctly the voltage fluctuations are pretty rapid.. about 3 to five times a second on cars that are adjusting correctly.... What happens if you disconnect the throttle position switch and then run the car? Not the maf just the throttle position switch

but let me try it again...

[billb]

but let me try it again...

Pulled a plug..here's what we look like after about 10 minutes total time of running at idle. I'm really suspecting the fuel at this point...it's just too dang coincidental that it's happening right after a fillup (when I was almost empty in the previous tank). Really considering buying several 5-gallon gas cans, siphoning this tank out, and starting fresh.

[632 Regal]

so this happened right after filling up??

[billb]

so this happened right after filling up??

Yep, within about 10-15 miles. Was going to try to drain the tank, but see no drain plug. Going to procure some 5-gallon tanks tomorrow and drain it all out, then put in some known good gas from my 318, and see what we get.

This is so frustrating. All sensors check out good, except I can't test the O2 sensor-it quits before I can get under the car and check the signal at the connector and checking it at the DME, I only get constant 0.45 V, even when it should be closed loop.

[632 Regal]

double check that. I wonder if someone messed up and put some deisel in the tank when filling it up. (not you but at the station)

[Bill R.]

already running and see if it still stalls then...







Yep, within about 10-15 miles. Was going to try to drain the tank, but see no drain plug. Going to procure some 5-gallon tanks tomorrow and drain it all out, then put in some known good gas from my 318, and see what we get.

This is so frustrating. All sensors check out good, except I can't test the O2 sensor-it quits before I can get under the car and check the signal at the connector and checking it at the DME, I only get constant 0.45 V, even when it should be closed loop.

[billb]

already running and see if it still stalls then...

...then starts the up/down idle, eventually choking itself out. Tried the same thing with MAF (unplug before starting up), and it did the same thing.

Should I feel vacuum at the oil filler hole with the cap off? None noticeable. Also no change in engine running with dipstick out. Strong vacuum at brake booster fitting. Vacuum at FPR and at "PCV" induction hose (small one). Can't feel vacuum at idle circuit feed hose from valve cover...will check idle circuit feed from MAF boot in a few minutes (had to get out of the garage for the fumes...)

Hello, AAA? Roadside emergency? Not exactly...

[ryan roopnarine]

...then starts the up/down idle, eventually choking itself out. Tried the same thing with MAF (unplug before starting up), and it did the same thing.

Should I feel vacuum at the oil filler hole with the cap off? None noticeable. Also no change in engine running with dipstick out. Strong vacuum at brake booster fitting. Vacuum at FPR and at "PCV" induction hose (small one). Can't feel vacuum at idle circuit feed hose from valve cover...will check idle circuit feed from MAF boot in a few minutes (had to get out of the garage for the fumes...)

Hello, AAA? Roadside emergency? Not exactly...


i aint bill, buuutttt....maybe its your idle control motor is dying? if you are gonna start borrowing parts, maybe consider borrowing that as well.

[632 Regal]

should be noticable but with the car running that shitty I dont know. It has to be something stupid and all these symptoms are adding up...to what I dont know.

Its NOT the O2 sensor cause that isnt even working when the cars cold.

No vacuum at oil cap OR idle valve is definetly trying to tell you something.

[billb]

The esteemed Mr. Bill R. has offered many valuable insights on this problem. Thanks also Jeff and Ryan for your continued suggestions. JR gave me a call (on his nickel!) Saturday-sorry I missed the call JR...was at work finishing up inventory. ScottyWM has offered up his AFM for me to test out my car (hopefully this evening!). If all this fails, the car is being driven to First Class Automotive here in Raleigh and hooked to MODIC. I am almost at wits' end, and have nothing but a nasty garage and sick car to show for it (plus several hundred (?) dollars about to go flying out of my account)...

Thanks guys.

[ryan roopnarine]

you may or may not have confirmed this with someone that called you earlier and that has an m50...but....i don't have vacuum from either the oil cover or dipstick within 4 mins of startup, and pulling the dipstick out doesn't cause any change. if you'd like, i know its late to be offering, i can mail you an icv for testing purposes if you want. i carry it in my toolbox as a spare. if not, no problem.

[billb]

you may or may not have confirmed this with someone that called you earlier and that has an m50...but....i don't have vacuum from either the oil cover or dipstick within 4 mins of startup, and pulling the dipstick out doesn't cause any change. if you'd like, i know its late to be offering, i can mail you an icv for testing purposes if you want. i carry it in my toolbox as a spare. if not, no problem.

mine "seems" to be functioning properly. 12 kOhms on terminals 1-2, 2-3. 24 kOhms on terminals 1-3. Swings well open to shut, applying a 9V battery appropriately. I'm leaning heavily towards DME errors...I hate this "electronic death" stuff. Give me a sticking valve, a leaky float bowl, something I can SEE!

[632 Regal]

mine "seems" to be functioning properly. 12 kOhms on terminals 1-2, 2-3. 24 kOhms on terminals 1-3. Swings well open to shut, applying a 9V battery appropriately. I'm leaning heavily towards DME errors...I hate this "electronic death" stuff. Give me a sticking valve, a leaky float bowl, something I can SEE!

[ryan roopnarine]

i sincerely hope it is your MAF.

[billb]

Same behavior with stock chip...

[billb]

...and I finished tightening up the last hose clamp, which of course involved removing the throttle body...(sorry Scott!). We carefully removed the MAF from his car and installed on mine, then fired it up. From cold start, it had been taking about 2 minutes before symptoms showed up. We must have let the car run for 5 minutes at least before shutting down. No issues. Shut it off, restarted, purred like a kitten. Okay, we thought. Shut it down, unplug his MAF, reinstall my MAF. Fired up, and it immediately shut off. Repeated this a couple of times, then it would do the bouncy idle then shut off. Hmmm, I think we have a winner.

Gonna cancel my appt. with the indy...

THANKS ALL!! Will advise when my new "used" MAF arrives on how she runs. Ought to be real good, with new FPR, O2 sensor, and every vacuum hose known to man snug and secure!

Whew...

[Jr ///M5]

Yeah!!! Good going guys! Way to team up on that thing. Just consider the things you did to it before the MAF, preventive maintenance....=)

Scott, it's people like you that make the board work. Congratulations goes to Bill, and we tip our hats to you. Scott, a true gentleman.

Now it's time for that cold one, huh boys?

Jr

[Jr ///M5]

Oh yeah, Bill.....I was going to tell you it was the MAF on Saturday when I called.....=) he,he,he....

Jr

[billb]

Now it's time for that cold one, huh boys?

Jr

Done deal. Scott and Lainey enjoyed a cold CPA while I was buttoning everything back up. BTW, Scott's got a VERY nice iT. His description of his interior job (done by him) doesn't do it justice. It looks FANTASTIC. Thanks again for your trust, Scott!

Jr, Ryan, Jeff, Winfred, Bill R., bimmerdood, Steven, Bret and others whom I owe one (can't recall everyone who advised)...you know who to call when you're in my neck of the woods.

Attached a picture of my sentiments to Mr. Bosch.

[632 Regal]

Freakin awesome!!!!!


MAF

wonder what the problem with it is?

[Bill R.]

and see whats faulty with it?






Done deal. Scott and Lainey enjoyed a cold CPA while I was buttoning everything back up. BTW, Scott's got a VERY nice iT. His description of his interior job (done by him) doesn't do it justice. It looks FANTASTIC. Thanks again for your trust, Scott!

Jr, Ryan, Jeff, Winfred, Bill R., bimmerdood, Steven, Bret and others whom I owe one (can't recall everyone who advised)...you know who to call when you're in my neck of the woods.

Attached a picture of my sentiments to Mr. Bosch.

[1995 525i]

Would either of you guys be "willing" to let me borrow your AFM for a few minutes? I'm trying to find out why my 525 goes through this wonky rich running thing, and I've tested/replaced everything but that. New FPR, new O2 sensor; checked and verified correct operation of ECT, IAT, TPS, CPS; all injectors firing (and clean!), all coils firing. I'm nearing wits' end...

I'm in the phone book, under Bass William, or shoot me an email. It's in my profile. I'm at work this morning (Saturday) until noon, then free from noon -4, and most of the day tomorrow (Sunday).

Thanks guys!

Haven't logged in for a while. Been really busy, sorry. Do you still need help?

[billb]

Haven't logged in for a while. Been really busy, sorry. Do you still need help?