1995 E34 525i Still will not start

[pcross]

Here goes...Several days ago after running like a dream, my 525i would turn over, but not start. Here's what I have done: 1) I replaced the fuel pump. 2) I pulled all the spark plugs and cleaned them. 3) I checked the coils for spark -good hot spark all around. 4) I jumpered the fuel relay terminals 87 to 30. I checked the fuse. In fact since there is only voltage to the fuse in start/run, I jumpered directly to the fuse so I could hear the pump run - At the fuel rail it sounded like air was being pumped in. 5) I pulled the feed hose from the pump and got a good, strong flow of fuel from it. I have checked everything I can possibly think of, but cannot get the car to start. The last check I can think of is to siphon some fuel from the bottom of the tank to check for water. It sure as hell isn't out of fuel! ANY HELP - SUGGESTIONS - would be greatly appreciated.

[shogun]

CPS? Measure the crankshaft position sensor.

Fuel with water might also be a possibilty. Experienced that once many moons ago with my old VW beetle. Also started changing everything first before I started thinking and diagnozing. So when did it start=shortly after leaving gasoline station. So I just removed a fuel hose, started the fuel pump some seconds and filled a plastic bottle, let it sink for some time, voila, water separated by gravity to the bottom of the bottle and I could clearly see the separation zone between fuel and water. Water has a different specific gravity, so it will be always at the tank bottum unless stirred. So if there is water in tank, it is at the bottom and your fuel pump will send it to the engine room. No need to drain a sample from bottom of tank.

You also mentioned that it sounded like air is beeing pumped. So remove the fuel hose in the engine room, get a plastic bottle and then start the fuel pump so that you can see it.

[Rick L]

I know if you have OBDII, you can check for fault sensors like crankshaft position sensor and camshaft pulse sensor. Code on E34 show this if faulty? If either of these sensors are bad, your car will not start.



CPS? Measure the crankshaft position sensor.

[Ross]

Three things are needed for the engine to run; fuel, spark and all the mechanical bits(and spark) to be in time.
You have eliminated spark(?) and suspect no fuel. Introduce fuel to the engine by spraying some carb cleaner or other flammable to the intake. If she runs it's a fuel delivery problem. If not and you are convinced spark is present and "on time" you have a mechanical issue.

[pcross]

Shogun, Rick and Ross....I'm going to cover all of the bases you recommended this Saturday....I'll be back.

[whiskychaser]

Introduce fuel to the engine by spraying some carb cleaner or other flammable to the intake. If she runs it's a fuel delivery problem.
x1. Egg-cup full of petrol if my preferred method. Maybe not if you are of a nervous disposition or have a hang up about health and safety:)

[alex 1993 525i auto]

You said that
At the fuel rail it sounded like air was being pumped in. 5) I pulled the feed hose from the pump and got a good, strong flow of fuel from it.

Would you have inverted fuel lines (feeding/return line), if you hear air like sound in fuel rail while jumping fuel relay? Maybe also clogged fuel filter/fuel line between pump and manifold?

Concerning the suggestion of CPS, if you have spark while cranking it seem your CPS works fine.

It is possible the fuel pressure regulator is faulty, like if its internal valve is stuck closed, no fuel goes in manifold.

Might be worth to see if you have fuel coming out after the FPR or pressure test it.

[pcross]

1995 525i - the one that won't start........I just ran a carsoft diagnostics program on my 525i and the only error message I get is 01 - Key not recognized. Then it gives me the sequence that the EWS goes through recognizing and accepting the transponder signal before OK'ing a start command to the DDE. I didn't know my key had a transponder module. Does it? I can't tell by looking and my owner's manual does not address it.

[Rick L]

I don't think '95 E34 has transponder in key but not 100%. Eitherway, it won't be your key if you have transponder and transponder failing or not since you mentioned your car turns over but doesn't start. Bad transponder for BMW will disable starter but not in your case.



1995 525i - the one that won't start........I just ran a carsoft diagnostics program on my 525i and the only error message I get is 01 - Key not recognized. Then it gives me the sequence that the EWS goes through recognizing and accepting the transponder signal before OK'ing a start command to the DDE. I didn't know my key had a transponder module. Does it? I can't tell by looking and my owner's manual does not address it.

[pcross]

I know the EWS disables the starter if someone tries to start the car without a key - a break-in, but I understand the starter can operate if there is an EWS / DME "misalignment." What do you think?

[wh377428]

it might be due to crankshaft sensor!!!

[Rick L]

EWS "misalignment" will cause ignition to fail. Not sure where you read that your starter will still turn over because it won't if EWS "misaligned". Any issue with EWS, you can't even crank.



I know the EWS disables the starter if someone tries to start the car without a key - a break-in, but I understand the starter can operate if there is an EWS / DME "misalignment." What do you think?

[pcross]

Thanks for all the input guys. The Beemer is going to the dealer Monday. The Carsoft diagnostic reads EWS error, "Key Not Recognized." I'll let the dealer guys figure it out.

[nicenup]

You may want to check the CPS (crank shaft position sensor) if you haven't done so already. Good luck!!!