1995 525i cranks but won't start

[mccustech]

Hello Everyone. Thanks to a random phone call from JFJ707 I decided to join this forum. He said that someone here may be able to assist me. I have a 1995 525i that won't start. I came out of the store one evening, cranked the car, it ran for about 2 - 3 secs, and it just died. It hasn't started since. I've replaced the battery, checked all of the relays (I think) and performed the relay jumper test, checked all of the fuses, replaced the camshaft position sensors, replaced the fuel pump, and replaced the starter. Still nothing. I took it to my mechanic to have the crankshaft position sensor replaced. He informed me that based on everything I have done, and with him changing the crank position sensor, the problem with the car is the ECU. Does anyone else have any ideas on what it could be? I've already sunk a great deal of money into getting to this point. Thanks.

[GTLee]

Probably the ECU. Not being flippant, but that's likely the problem.

[jfj707]

Hey guys, as Mike said I gave him a call to see if I could help. His mech wanted to charge about $800 for a reman ECU and "programming".

I'm not really sure how to test the ECU so I figured someone here could help him - although I realize that may not be the problem after all.

BTW, if I remember correctly, even if your car has EWS, you can swap in a red label 413 ECU, or if the EWS is acting up and causing a no start (if you have it...) you can modify something to get rid of it.

Someone correct me if I am off, please.

[makaveli2k]

I'm going to second the thought of ECU, I just had this problem a week ago and this cured it.

[David325e]

Have an alarm or had any alarm problems in the past?

And just a trick, but try it please. Disconnect the leftmost (driver's side) line from the fuel pump and crank the car. See if it starts then.

Don't know too much else to check, but generating ideas I hope.

[jfj707]

Originally Posted by David325e

Have an alarm or had any alarm problems in the past?

And just a trick, but try it please. Disconnect the leftmost (driver's side) line from the fuel pump and crank the car. See if it starts then.

Don't know too much else to check, but generating ideas I hope.

Never heard that one... what's it do?

[David325e]

Originally Posted by jfj707

Never heard that one... what's it do?

No idea

But I when I had the M20, it had this problem where when it was cold (it was about 6degrees for a week here last year) or even when it was warm if there was a big temp change it would crank then die. I'd start it, get normal idle for about 25 seconds then die. Or, if I got on the accelerator it'd move for about the same time then die. It happened once a few months after I got the car. I disconnected that feed line to see if the pump was working and when my buddy turned the car it started.

So whenever I had that issue I'd do the hose trick. Car would start right up, reconnect hose and be on my way. Never happened when the car was running or idling, or ever after sitting if it'd been less than over night. Only annoying parts were that it was usually 6am when I was in a hurry to get out of the dorm parking lot or once it made me late to a job interview.

I mentioned the problem in a few threads but no one ever had a solution. And I only drove the car like that about 5months before I wrecked it so...

[mccustech]

I'm at the Fire Station right now and can't try the fuel line disconnection idea. I'll try it tomorrow and let you know. Thanks.

[acepilot]

You probably know this but did you check the basics: pull a plug and see if it sparks, check the plug tip after cranking to make sure you have fuel. Does the 525 have a distributor? If so, check the caps and rotors. One of those two must not be working. Finally check the timing.

Ace

[e32 735il]

check the distributor cap and rotor
i dont know much about 5 series but i think thats it

[acet]

I guess its the 5 series virus that is going around GA. Welcome to the club...lol

[jfj707]

Originally Posted by acepilot

You probably know this but did you check the basics: pull a plug and see if it sparks, check the plug tip after cranking to make sure you have fuel. Does the 525 have a distributor? If so, check the caps and rotors. One of those two must not be working. Finally check the timing.

Ace

Originally Posted by e32 735il

check the distributor cap and rotor
i dont know much about 5 series but i think thats it

Only the M20's have a distributor. (89-90)
M50's have individual coil packs.

[acet]

With a voltmeter, check the coilpacks for spark.

The, disconnect the fuel line from fuel rail and try to crank the car. Does fuel come out?

First thing to figure out is what is causing the car to not start: Timing (mechanical), Spark, or Fuel. You need all 3 for the car to start.

From there, you can see what it can possibly be caused by.