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E34 (1989 - 1995)

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  #26  
Old 09-28-2013, 09:51 PM
sse34 sse34 is offline
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Mein Auto: E34 530it
not starting

Yea it's always the things you would never assume

Good find


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  #27  
Old 09-29-2013, 04:07 AM
Mamij Mamij is offline
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Mein Auto: BMW 320i M52 1996
This does not make sense. Busted MAFs do not lead to no-start issues. It must have exacerbated something else that is also at fault in your car. Sleepysal, I suggest you keep looking. The lack of error codes does not indicate that everything is working perfectly. The E34's error code reporting system is an early generation one, and is well known for keeping busted sensors online and screwing up the car.

If I were you, I would change the other two important sensors on the car besides the maf. The would be the ects and the IAT. Both of them can cause overfueling when damaged, and perhaps, together with a busted maf, they combined to generate a no start. They both only cost $25 each for oem units and are not hard for a skilled DIYer to change out. The IAT should also be relocated to the airbox, as Dr Bert highlighted to us in his recent thread that Turner MS recommended, for more efficient car running. This is not a difficult modification to make. Much easier than troubleshooting something without proper diagnostic and graphing tools, and its cheap and the car is a keeper, winter is coming when buggy ects units rear their fugly heads anyways, so why not ?

Sniff the engine generally, when cold. Key2 the ignition, and sniff. You should not smell anything that suggests fuel.Also, take a look at your fuel pressure regulator, specifically the vacuum hose that's attached to it. Pull the hose and sniff it. If it smells of gasoline, then your regulator is busted and leaking fuel into the intake through the vacuum hose. This could combine with something else to cause a flooding situation in the chamber.

And no SSE34, when the cps is busted, the starter is still functional. You will be able to crank fine, but the engine will not catch as spark and fuel would not be authorised by the ecu. The circuits are independent. The starter would function even if the ecu is disconnected, for the same reason.

SSE34, unlike some over here, I honour your drastically contradictory observations and report. I will not assume you are a troublemaker, liar or working for a lobbyist. Would you mind disconnecting your cps and trying to crank the car again? Its easy to undo and redo for an M50 engine. Please publish your report her after you're done. It should be interesting, and we might help you trace a different problem on your car.

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  #28  
Old 09-29-2013, 11:25 AM
sse34 sse34 is offline
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Mein Auto: E34 530it
not starting

I was thinking that myself that the MAF Just made things worse and not necessarily the main cause.

As for the CPS confusion thats what I have read and witness but again maybe there is still something else wrong In combination with the bad CPS which caused my car not to crank

Couldn't tell you

But that's what I was thinking fuel related originally was the FPR or vac plate or a simple filter

I do agree there is a hidden cause not showing itself



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  #29  
Old 10-07-2013, 10:33 AM
sleepysal sleepysal is offline
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Well a week later and she is running better then before. She fires right up, idles good and the throtle response is good.
Maybe the bad MAF flooded the engine? Dont know but whar ever it was seems to be gone. I will let you know if it surfaces again. Thanks
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  #30  
Old 10-07-2013, 11:09 PM
Mamij Mamij is offline
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Hi Sleepysal,

Yes, a bad MAF, like a bad ects, can flood the engine. However, merely disconnecting it should solve the problem. When you disconnected your bad maf, did your engine perform otherwise normally? It should perform normally - you will only notice something wrong when you look at the poor fuel economy numbers. If the engine still performed badly (i.e. rough idle, hunting, etc) then something else is also busted. Generally, two driveability sensors cannot be busted at the same time and the engine appear to function normally. One can be disconnected or voided by the ecu through an error code, and the car will still be ok.

You can try this now on your good maf. Disconnect it, then start the engine. Give it a minute to settle and then see if your engine appears normal. It should. Then shut it down, reconnect, and use the stomp test to check and clear error codes.*

I would still recommend that you change the iat and relocate it to the airbox, and change the ects. Its $25 each for oem units and since you are keeping your car, a mere $50 and 30 -45 minutes to do both (including relocation) is very worthwhile.

Thanks for keeping us updated and good luck.


Mario

* If you see an error code for a drivability sensor (iat, ects, maf, o2 sensor, icv), take note of it, clear them, drive for the next 2 days and check again. Take action on repeated codes.
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  #31  
Old 10-08-2013, 07:35 AM
sleepysal sleepysal is offline
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Thanks Mario. Any info on the iat relocate ?
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  #32  
Old 10-31-2013, 04:29 PM
sleepysal sleepysal is offline
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Just an update. as of today 10/31/13 she is still doing fine. Staringing up, idling ,and running so far so good.( Man I hope I just didn't jinx myself!)
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  #33  
Old 12-16-2013, 08:21 PM
sleepysal sleepysal is offline
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12/16/13 still going strong.
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  #34  
Old 12-22-2013, 06:56 AM
Mamij Mamij is offline
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Quote:
Originally Posted by sleepysal View Post
12/16/13 still going strong.
Thank you for updating your thread sleepy and merry christmas!
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