1995 540i won't start

Originally Posted by rv6rick

Howdy,

I unplugged the battery for 48 hours then plugged it back in and no change in the car.

I rang out the wires for the MAF sensor from the pins #14 and #41 at the DME to the pins at the MAF connection and wires are good. Also the ground and 12V+ wires at the MAF sensor are good to ground and show 12V+ respectively.

Current situation is as follows:

-with clear codes and 2nd brand new MAF sensor plugged in.....

1-starts right up but idles rough
2-runs like a dog when put into drive and trying to accelerate
3-takes about 20 to 30 seconds to get up to 40mph and asking it to faster is a joke
4-On board computer says it's getting about 7 to 11 mpg
5-won't get out of it's own way....literally
6-check engine light comes on and when stomp test is done there must be 6 or 7 codes in there

-with clear codes and 2nd brand new MAF sensor UNPLUGGED

1-starts right up but will NOT run below about 1000 to 1200 rpm
2-once in drive and accelerating it goes pretty good but sometimes you have to run the revs up pretty high to get it to shift
3-whenever you slow for a stop sign or light you MUST keep one foot on the brake and one on the gas pedal or you will NEVER keep it running. It will die as soon as you stop
4-check engine light comes on but I only get the MAF sensor code
5-on board computer reads about 15 to 16 mpg

Can't drive the car anywhere like this as it's basically unsafe and unreliable .

Thanks for any additional info.

The guy that figures out what it the matter with this 'car' (I use that term loosely) will get a nice booby prize .

I've been trying to get this thing running since the 1st of January. I DID work through the 'crank but no start' issue and the 'no oil pressure' due to all the crud from the fuel wash but now it's got this problem that mysteriously appeared while all the other stuff was going on.

I've about had it.

Rick in Ohio

Hello Rick,

Ten days ago, you did the exact same thing as what you said you did in your post today. The engine was bad then, but is normal now. I don't think a dead air temp-sensor can cause this, it could not have Coincidentally died when you installed the new maf and removed the dme clamp. And if the sensor is dead, the dme will just ignore it and used stored aproximate values.

Can you unplug the fake air sensor alone together with the maf unplugged, and see if the engine behaves normally ? Faking the air sensor is a great karate move, only a hero can think that up. I'm going to remember that.
From what I know, a new china maf will work if it has the same part number. And you have used 2 new mafs. Did they look the same as the old maf ? I don't think that changing this to original will work. Maybe I am wrong. But the original maf is very expensive.

I am still interested in buying your car for my roadtrip. I will sell it back to you at cost on my way back, if you agree. But if you can't store it for me until august, and someone else wants to buy it now, then I will understand.

I don't 'think' that I did it the same way as I did it this time...or I possibly miscommunicated .

I DO know that I 'didn't know' that the air temp sensor was bad until the other day when I unplugged the MAF senser AND cleared the codes AND unplugged the air temp sensor and plugged the connector into a 'fake' one. I'll also add that the 'fake' sensor didn't work as well when it was touching the HOT intake manifold. It was when I laid it up against the COOL fuel rail that it made the biggest difference. I dunno....just sayin' .

Thanks for the info on the MAF sensor. I DO KNOW that BOTH of the MAF sensors that I got from eBay were DIFFERENT than the one I had in there (that also didn't work). Mine had TWO little 'open' resister type thingys sticking out into the breeze and the 2 replacements (that don't work) only had 1. I wrote it off as a 'new model' but now I'm thinking it may have a lot to do with the issue. Right now it's worth pursuing as I feel I can always refert to the way things are connected (not connected ). I'll look this up later today....headed out for Church right now.

Rick in Ohio

Originally Posted by Mamij

Hello Rick,

Ten days ago, you did the exact same thing as what you said you did in your post today. The engine was bad then, but is normal now. I don't think a dead air temp-sensor can cause this, it could not have Coincidentally died when you installed the new maf and removed the dme clamp. And if the sensor is dead, the dme will just ignore it and used stored aproximate values.

Can you unplug the fake air sensor alone together with the maf unplugged, and see if the engine behaves normally ? Faking the air sensor is a great karate move, only a hero can think that up. I'm going to remember that.
From what I know, a new china maf will work if it has the same part number. And you have used 2 new mafs. Did they look the same as the old maf ? I don't think that changing this to original will work. Maybe I am wrong. But the original maf is very expensive.

I am still interested in buying your car for my roadtrip. I will sell it back to you at cost on my way back, if you agree. But if you can't store it for me until august, and someone else wants to buy it now, then I will understand.

Originally Posted by rv6rick

I don't 'think' that I did it the same way as I did it this time...or I possibly miscommunicated .

I DO know that I 'didn't know' that the air temp sensor was bad until the other day when I unplugged the MAF senser AND cleared the codes AND unplugged the air temp sensor and plugged the connector into a 'fake' one. I'll also add that the 'fake' sensor didn't work as well when it was touching the HOT intake manifold. It was when I laid it up against the COOL fuel rail that it made the biggest difference. I dunno....just sayin' .

Thanks for the info on the MAF sensor. I DO KNOW that BOTH of the MAF sensors that I got from eBay were DIFFERENT than the one I had in there (that also didn't work). Mine had TWO little 'open' resister type thingys sticking out into the breeze and the 2 replacements (that don't work) only had 1. I wrote it off as a 'new model' but now I'm thinking it may have a lot to do with the issue. Right now it's worth pursuing as I feel I can always refert to the way things are connected (not connected ). I'll look this up later today....headed out for Church right now.

Rick in Ohio

Could I ask you to post internal pictures of both the original and new maf?
Are the part numbers stamped on the outside of both mafs?
Thanks

I don't have pics as one of them is on the car and you can't read the number due to the location. I DID talk to the folks where I purchased it and i read the number that was on the MAF sensor to them. They said that the number was ONLY the type of plastic used in the mold. Which means I have a super duper cheapo unit that either doesn't work on the car or that doesn't like the air intake temp sensor...or visa versa.

I hope to have this worked out by tonight and should come up with some kind of a plan (other than big bucks on a new Bosch unit) by early next week.

Rick in Ohio

Originally Posted by Mamij

Could I ask you to post internal pictures of both the original and new maf?
Are the part numbers stamped on the outside of both mafs?
Thanks

Originally Posted by BMR_LVR

Have neither of you ever reached the point of frustration at something that you just wanted to throw your hands up in despair and give up? If not, then count yourselves blessed.

That is what Rick went thorough. I have a million times more respect for Rick and what he went through and the efforts to get his car running (despite some horrible advice from some members here) than I do for you two to come here and make such judgmental remarks.

I got this from the other thread. I stand with you on respect for the Bimmer Hero. Whatever it is, he's the one in front of the car with the issue, soldiering on. We can cut him slack where we can.

I've moved this reply here due to this comment of yours :

Originally Posted by BMR_LVR

That is what Rick went thorough. I have a million times more respect for Rick and what he went through and the efforts to get his car running (despite some horrible advice from some members here) than I do for you two to come here and make such judgmental remarks.

Where was the 'horrible advice' from other members here ? I didn't see you pointing anything out as being unwise. Please let us know so that we can all learn. Thanks.

Hey guys,

I wanted to bring you all up to speed on the FINAL OUTCOME of my '05 540i and offer a little summary:

Remember that I had been driving for YEARS with the MAF sensor unplugged. The first 2 replacement MAF sensors were eBay cheapos for about $45 bucks. Both of them caused my car to simply GO WILD with all kinds of codes coming in and the car bucking and kicking and losing power and virtually undrivable. I wound up unplugging the sensor and the car ran pretty good. I've been driving it for a good week now and NO ISSUES other than the CEL with the MAF sensor code.

I installed my 3rd MAF sensor today. This one was a used salvage BOSCH unit from another '95 540i, it set me back $43 including shipping. I put it in and cleared the 1215 MAF sensor code and started the car. The CEL was out and the car idled SMOOTH AS A KITTEN.......whoa baby . Took it for a drive and the car was AMAZING.....smooth as silk and the OBC kicked up another 2-3 mpg. My last two tanks of gas averaged 18.5 mpg with mostly around town driving and some highway....I verified the OBC to be 100% accurate with my actual mileage and fuel consumption. All highway would yield about 23.8 mpg. I can't wait to see what my gas mileage is now.

So, the moral of the story here is DO NOT BUY THE CHEAPO units from eBay...I'm sure I was warned about this but I'm a cheapskate and didn't want to take a chance on the $200+ unit. This used BOSCH unit was the ticket to fix my car once and for all! The car hasn't run this good in MANY MANY years !!!

What a shame as the car won't be here much longer. Bad for me and good for the new owner. My replacement little Focus is expected to be ready by the middle of March. I'll keep driving the Bimmer till then...hopefully she'll run well!

Oh yea, I still have the air temp sensor 'dummy' in place and it's still taped to the cool fuel rail. It must be fooling the system because I'm getting no sense of it 'not' being OK. I just checked the tracking on the new one and it will be here tomorrow. 12 days to get it here....rediculous! I'll put it on tomorrow just to close that chapter.

Just so you know, the car will be going to an 19 year old motor head kid that hangs around the airport all the time and visits me at my shop. He's a nice Christian boy that just needs a break. He's broke and his mom lets him use her car to get around sometimes. He has been dreaming about this car for a long time and wanted it 'as is' but, he is even happier that it's all dressed up and is ready for the big game .

You guys are simply AMAZING!! Thankya'....Thankya'.....Thankya' !!!

Rick in Ohio

Great job! That kid sounds like good candidate for the car. Glad someone will love it. He's welcome here anytime!

Sent from my SPH-L710 using Bimmer App

Originally Posted by rv6rick

Hey guys,

I wanted to bring you all up to speed on the FINAL OUTCOME of my '05 540i and offer a little summary:

Remember that I had been driving for YEARS with the MAF sensor unplugged. The first 2 replacement MAF sensors were eBay cheapos for about $45 bucks. Both of them caused my car to simply GO WILD with all kinds of codes coming in and the car bucking and kicking and losing power and virtually undrivable. I wound up unplugging the sensor and the car ran pretty good. I've been driving it for a good week now and NO ISSUES other than the CEL with the MAF sensor code.

I installed my 3rd MAF sensor today. This one was a used salvage BOSCH unit from another '95 540i, it set me back $43 including shipping. I put it in and cleared the 1215 MAF sensor code and started the car. The CEL was out and the car idled SMOOTH AS A KITTEN.......whoa baby . Took it for a drive and the car was AMAZING.....smooth as silk and the OBC kicked up another 2-3 mpg. My last two tanks of gas averaged 18.5 mpg with mostly around town driving and some highway....I verified the OBC to be 100% accurate with my actual mileage and fuel consumption. All highway would yield about 23.8 mpg. I can't wait to see what my gas mileage is now.

So, the moral of the story here is DO NOT BUY THE CHEAPO units from eBay...I'm sure I was warned about this but I'm a cheapskate and didn't want to take a chance on the $200+ unit. This used BOSCH unit was the ticket to fix my car once and for all! The car hasn't run this good in MANY MANY years !!!

What a shame as the car won't be here much longer. Bad for me and good for the new owner. My replacement little Focus is expected to be ready by the middle of March. I'll keep driving the Bimmer till then...hopefully she'll run well!

Oh yea, I still have the air temp sensor 'dummy' in place and it's still taped to the cool fuel rail. It must be fooling the system because I'm getting no sense of it 'not' being OK. I just checked the tracking on the new one and it will be here tomorrow. 12 days to get it here....rediculous! I'll put it on tomorrow just to close that chapter.

Just so you know, the car will be going to an 19 year old motor head kid that hangs around the airport all the time and visits me at my shop. He's a nice Christian boy that just needs a break. He's broke and his mom lets him use her car to get around sometimes. He has been dreaming about this car for a long time and wanted it 'as is' but, he is even happier that it's all dressed up and is ready for the big game .

You guys are simply AMAZING!! Thankya'....Thankya'.....Thankya' !!!

Rick in Ohio

Its really super that you've given a young dude a chance like this, and a great car. I'll give up my Great American driving vacation for that. Kudos to you Rick.