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E34 (1989 - 1995)

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  #1  
Old 10-02-2010, 02:10 AM
Dennis' first B Dennis' first B is offline
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Mein Auto: 1994 525i BMW
only starts with starting fluid

I have a 1995 525i. I put a new head on it a few months ago and it ran like a top up intil a few weeks ago. One morning it wouldn't start. I bought starting fluid to see if it was fuel. I sprayed some in the thottle body and it started right up. The first few days if I drove it and shut it off I could start it again. After a week or so it got to where it would not start unless I sprayed fluid in the throttle body. One it starts it runs great. I can drive it anywhere. It have plenty of power I just can't turn it off or it will only crank unless I spray starting fluid in it. I took it to a shop today. I'm tired of looking. In case they don't find anything does anyone have any suggestions?

Thanks

Dennis
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  #2  
Old 10-02-2010, 03:51 AM
robertobaggio20 robertobaggio20 is offline
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No shop would be so useless that they wouldn't find anything. But anyway, dennis, you should pull the error codes from your car via the stomp test, and perhaps have your fuel injectors, fuel pressure regulator, fuel pressure, fuel pump and fuel filter checked out.

You may need to check out your air filter and air passages right from where the air first goes in all the way to the throttle body to see if there's any problems.

Have you tried starting your car with the throttle fully opened i.e. pedal down fully?

Let us know what your mechs discover, thanks.
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  #3  
Old 10-02-2010, 07:28 AM
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BMR_LVR BMR_LVR is offline
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Dennis, it sounds like it is likely your fuel pump. Remotely possible that it is your fuel pump relay. If it cranks with starter fluid (don't do this much as it is very hard on the engine) but then runs, then it sounds like your fuel pump isn't able to generate quite enough pressure to get enough fuel to the cylinders, but is able to get enough to keep it running.

I agree with Roberto that it may be the fuel pressure regulator. It may be on it's way out. Make sure your mechanic checks that as well.

Good luck and let us know what you find out.

Steve
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Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #4  
Old 10-02-2010, 12:58 PM
robertobaggio20 robertobaggio20 is offline
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bmlvr, if the fuel pressure regulator fails, what should happen? Will the fuel pressure in the system increase, or will it shut down entirely? Obviously the regulator keeps fuel pressure at the correct level, but i'm not sure how it accomplishes this.
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  #5  
Old 10-02-2010, 02:05 PM
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BMR_LVR BMR_LVR is offline
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I'm not totally familiar with how they work, but Iwould think that if the regulator failed, it would cause a low/no fuel pressure situation thus not allowing an engine to run.
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Most problems are usually something simple !

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It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #6  
Old 10-02-2010, 03:19 PM
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Radian Radian is offline
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In our case, the fuel pressure regulators are vacuum operated, pulling against a spring that's always pushing the plunger inside closed. The plunger controls how much fuel flow is allowed to by-pass the injectors. Against full vacuum, the plunger is pulled wide open, reducing rail pressure to a prescribed minimum.

Therefore they fail (the vacuum bellows leak or the hose is cracked) causing high pressure. It would make for a rich condition.

It's why sometimes you get a no-start if you don't let the engine crank long enough when the engine is hot. There's not enough vacuum present to open the regulator immediately. Then the re-start attempt is a minor biotch until the excess of fuel clears out of the cylinders.

Diagnosis is easy enough....rent a Brake Vacuum bleeder from Auto Zone make sure it's the kind with a gauge on it. Un-plug the vacuum line from the Fuel Pressure Regulator (FPR) and attach the vacuum side of the pump to the nipple on the FPR. It's located below and at the rear-end of the fuel supply rail. Apply a steady vacuum signal to it and see if it holds. If the reading falls, it's junk because it's leaking.

If you end up having to replace it, it looks easy enough to get at. I don't know what's underneath there because I've never worked on an M50. Looks like around an hour for a competent mechanic to fix, if it comes to that.
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Last edited by Radian; 10-02-2010 at 03:30 PM.
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  #7  
Old 10-02-2010, 04:51 PM
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BMR_LVR BMR_LVR is offline
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Thanks for the FPR lession Radian

Now ..... if I only understood it
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Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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  #8  
Old 10-02-2010, 11:13 PM
Dennis' first B Dennis' first B is offline
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Mein Auto: 1994 525i BMW
I got a call from the shop. The Mechanic said he checked all the connections and started the car. He said it started several times, but he hadn't really done anything. I told him that maybe one of the connections unter the intake had come loose and he had put it back. I was going to go pick it up, but he called back and said he tried to start it again and it didn't start. He's going to keep it for now and check it again on Monday. I'm perfectly capable of tinkering with the car. I had hoped for a computer readout. I'll give him Monday, but if he's just going to poke around and charge me for it, I can do that for free.

So if the fuel pressure regulator vaccum line is cracked am I right in assuming the fuel will not enter the rail. and if I use starting fluid to start the car, and then the running car vaccum is enough to overcome the leak, could that be a possibility. Testing the regulator would find no problem, because the problem is in the vaccum line.

What do you think

Dennis
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  #9  
Old 10-03-2010, 05:30 AM
robertobaggio20 robertobaggio20 is offline
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Why did you send your car to someone who can't diagnose it with a computer system?
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  #10  
Old 10-03-2010, 06:24 AM
Dennis' first B Dennis' first B is offline
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They have computers. I made sure of that. All I know at this time is that he started with checking the connections. After checking the connections it started for him. He said after he called me and I told him I was coming down to get my car he tried to start it again and it didn't start. He didn't tell me that he did or didn't hook it up to the computer yet. I really won't know anymore until I go in and talk to them on Monday. Unless of course they call me and tell me they found the problem.

Dennis
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  #11  
Old 10-03-2010, 09:44 AM
robertobaggio20 robertobaggio20 is offline
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He's a clown. Even if it started for him after he checked the connections, he should always run a diagnostic on the car to see what the stored error codes are and to clear them after double checking that the component concerned is ok. He should have done this at least after it stopped working again. Please get him to scan the car immediately. I suggest you go there and be in attendance while he conducts the pc scan.
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  #12  
Old 10-03-2010, 12:33 PM
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Quote:
Originally Posted by Dennis
So if the fuel pressure regulator vaccum line is cracked am I right in assuming the fuel will not enter the rail.
No. If the line is cracked it'll default to having too much pressure.

To put your mind at rest, I seriously doubt the FPR is the sole cause of your starting issue. Don't know anything more than that.
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  #13  
Old 10-06-2010, 06:36 PM
Dennis' first B Dennis' first B is offline
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Location: Sacrametno
 
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Mein Auto: 1994 525i BMW
I got my car back today. It turns out it was the Crankshaft positioning sensor. It cost me $350.00. The only problem is that I was going to check that last weekend, but ran out of time. The upside is my car is back on the road. She runs and drive beautiful. No I start working on her looks. She needs paint. Right now she's green, but I'm going to paint her silver/blue.
Thanks for all your help. I'll post pictures when she's done.

Dennis
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  #14  
Old 10-06-2010, 07:21 PM
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BMR_LVR BMR_LVR is offline
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Location: Asheboro, NC
 
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Mein Auto: 1992 525i
Glad you got it back Dennis. Sorry we couldn't put you on the right course.
__________________
Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

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