91 525i Wants to start but refuses too

Originally Posted by Monsignor

pick up another DME. they go for the price of a full tank of premium. Check which one you have

Originally Posted by BMR_LVR

He has non-vanos. He should have brown label 402 DME.

There you go

Originally Posted by Monsignor

answer this as honestly as you can because i take everything with a grain of salt here (nobody wants to seem like a noob or an idiot and they lie about the thing that will fix the car, to their own demise)

Did the car ever right after that head gasket job by your buddy?

Also, please define "BMW Mechanic." Certified? Works at a dealership? Or is he a lot jockey with a wrench...

Im troubleshooting right now. Ill get back to ya'll

Originally Posted by E34_Obsession

Im troubleshooting right now. Ill get back to ya'll

what are you trouble shooting?

Double checking the ICV and putting fresh gas in it? waiting on the video

Sorry I have been absent guys... Quick question... Could the sensor that measures the amount of coolant that the car has prevent the vehicle from starting?!?

Originally Posted by E34_Obsession

Sorry I have been absent guys... Quick question... Could the sensor that measures the amount of coolant that the car has prevent the vehicle from starting?!?

No.

Originally Posted by Monsignor

waiting on the video

Originally Posted by Monsignor

you never took that video, so lets try that.

from the 11th. two weeks ago.

Originally Posted by BMR_LVR

No.

+1

1. Did you ever check the cams and the dots on the top of the squares at the back?
2. Did you pick up a DME?
3. Did you put fresh gas in it?
4. Did you double check your ICV?
5. Did you ever get it started?

EDIT @ 2:14PM 1/25/13 - OP is online but silent. WTH

Originally Posted by Monsignor

from the 11th. two weeks ago.



+1

1. Did you ever check the cams and the dots on the top of the squares at the back?
2. Did you pick up a DME?
3. Did you put fresh gas in it?
4. Did you double check your ICV?
5. Did you ever get it started?

EDIT @ 2:14PM 1/25/13 - OP is online but silent. WTH

Steady on

Originally Posted by _Ethrty-Andy_

Steady on

its hard to help people asking for it when they do this...

"My car wont start. It looks okay"

then radio silence

Originally Posted by Monsignor

its hard to help people asking for it when they do this...

"My car wont start. It looks okay"

then radio silence

Allright all! Here is the video of the cars behavior!!!

Cylinder wash. Oil in your chamber walls have been washed off too much by gas. Compression too low.

That's why your oil light goes off even while cranking and before she catches. Second and third start on the video. Too little resistance to crank, so it spins faster.

How would I go about restoring the compression?

Ok I will try that also I will disconnect the sensor. Is there a reason why I should? And is it the blue one in the head?

Hold the Phone, everyone.

Let's get back to square one here, that is:
-Fuel
-Air
-Spark
-Compression

Test for these, and if you have, tell us exactly how you tested for these 4 things.

see this if you havent:
http://forums.bimmerforums.com/forum...&highlight=m20

You must rule out those 4 things as problems.
Only then can you assume a bad ECU.

Has Fuel- Took fuel rail off and each injector spray's, also replaced fuel filter, fuel regulator, and they are new BOSCH oem injectors...

Has Air- New air filter, MAF is good, yadayadayada...

Has Spark- All six coils throw strong spark, also replaced spark plugs...

Has Compression- Used Snap-on compression testor, all six were in the 150-170psi range but all six were around 165ish.

Have you checked the throttle position sensor (TPS)?

I agree with steve about the TPS. I would also check the ICV. It kind of sounds like hell, man :/

You butterflying the throttle like that is sort of a manual idle control. The ICV isnt the easiest to get to (remove intake manifold) but that could very well be your issue. The TPS could also be just as likely. The motor doesn't seem to respond well if at all to being thrown WOT. Have you tried a less extreme "Floor it! Lift! Floor it! Lift etc" approach. Like holding it at 25%?

How could a bad TPS cause the engine to run as terrible as it does?

The engine doesnt recognize the throttle position. In the video you see OP smashing the throttle wide open without any reaction from the engine

The engine should run fine without the throttle position sensor. IIRC, it is just a switch to tell the ecu that the engine is at idle, off idle, or at WOT.




UNLESS, the M50 engine has a different TPS, but normally it would substitute a value in place of it.

Originally Posted by paperplane94

The engine should run fine without the throttle position sensor. IIRC, it is just a switch to tell the ecu that the engine is at idle, off idle, or at WOT.

It seems OP was going to WOT without reaction. Even still,

ICV could cause this.

Sounds like you have a massive vacuum leak after the MAF. Check the rubber boot before the throttle body