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E36 M3 (1992-1999) {Euro - S50 B32 321hp @ 7400 rpm} {U.S. - S52 B32 240 hp @ 6000 rpm}
Total Produced: 71,212 - Years Produced: 1992 to 1999


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Old Fri, Feb-10-2017, 01:31:39 AM   #1
Roofus
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Default Car won't cold start - fuel pressure, starter, or cam sensor?

My '97 M3 is having difficulties starting in the morning, especially if it is below 40F.

Things to know upfront:

There is a bad ground somewhere because I get alternator whine on the radio line-in to my iPhone through the CD changer harness.
The fuel filter was replaced in 2010.
Alternator checked and fine.
Battery checked and fine.

Symptoms:
Initial key turn to crank will not turn over engine. All lights, accessories, radio, A/C, dash, etc come to life no problem.
After several key turns to Accessory position, and after about 3-5min, the car will crank. (I know there is some debate as to whether each key turn primes the fuel or if it only allows that every few minutes).

Based on my research on the forums my symptoms could be bad fuel pressure, a bad starter, or a cam sensor. However I would assume a bad starter would be more consistent and would also assume I would get a CEL for a cam sensor fault. But those are just assumptions. I'm leaning fuel pressure, but curious how I can know for sure, and also if that is the case the best way to track it down?

Thanks for the help!My '97 M3 is having difficulties starting in the morning, especially if it is below 40F.

Things to know upfront:

There is a bad ground somewhere because I get alternator whine on the radio line-in to my iPhone through the CD changer harness.
The fuel filter was replaced in 2010.
Alternator checked and fine.
Battery checked and fine.

Symptoms:
Initial key turn to crank will not turn over engine. All lights, accessories, radio, A/C, dash, etc come to life no problem.
After several key turns to Accessory position, and after about 3-5min, the car will crank. (I know there is some debate as to whether each key turn primes the fuel or if it only allows that every few minutes).

Based on my research on the forums my symptoms could be bad fuel pressure, a bad starter, or a cam sensor. However I would assume a bad starter would be more consistent and would also assume I would get a CEL for a cam sensor fault. But those are just assumptions. I'm leaning fuel pressure, but curious how I can know for sure, and also if that is the case the best way to track it down?

Thanks for the help!

*UPDATED*: Just coming back in to let everyone know it was the starter. Popping the starter with a wrench or putting the car in gear and rocking it back and forth would loosen the jammed tooth in the starter and it would crank back up. Removing it showed that there was a filed down tooth that was jamming into the flywheel and preventing startup. Thanks for all the help guys!

Last edited by Roofus; Sun, Mar-12-2017 at 04:06:10 PM.
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Old Fri, Feb-10-2017, 02:02:55 PM   #2
M-technik-3
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

Have you checked to see if you have a broken engine ground? That's an easy and fast check.
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Old Fri, Feb-10-2017, 04:20:46 PM   #3
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

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Originally Posted by M-technik-3 View Post
Have you checked to see if you have a broken engine ground? That's an easy and fast check.
I have not. But will add to the check-off list. Thanks!
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Old Fri, Feb-10-2017, 05:27:22 PM   #4
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

When you say "engine won't turn over", some people mean that the engine won't start when they say that. Some people say it when the engine doesn't crank.

What it means is that the engine doesn't crank at all.

If your engine will not CRANK, then fuel pressure is irrelevant. That only comes into play if the car will not start, but does crank.

The cam sensor is the same. it will not stop the car from cranking.

"I get alternator whine on the radio line-in to my iPhone through the CD changer harness"- This doesn't mean that you have a bad ground. You are using SOME kind of aftermarket stuff to listen to an ipod. So it's possible that whatever this device is just has crappy ground isolation. That'll happen sometimes.

Things that keep the car from cranking:
Dead battery- not the case because your lights come on
Bad connection to starter- ground strap on engine and large red wire going to starter
Bad ignition switch- kind of hard to check, but it's possible
EWS malfunction- The antenna, key, EWS computer, or DME could all be faulty.

I'm leaning toward a bad EWS antenna or bad key since it has to sit for a while and then starts fine. If you have another key, just try it and see if the problem goes away.
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Old Fri, Feb-10-2017, 07:05:51 PM   #5
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

Quote:
Originally Posted by kevinwilly View Post
When you say "engine won't turn over", some people mean that the engine won't start when they say that. Some people say it when the engine doesn't crank.

What it means is that the engine doesn't crank at all.

If your engine will not CRANK, then fuel pressure is irrelevant. That only comes into play if the car will not start, but does crank.

The cam sensor is the same. it will not stop the car from cranking.

"I get alternator whine on the radio line-in to my iPhone through the CD changer harness"- This doesn't mean that you have a bad ground. You are using SOME kind of aftermarket stuff to listen to an ipod. So it's possible that whatever this device is just has crappy ground isolation. That'll happen sometimes.

Things that keep the car from cranking:
Dead battery- not the case because your lights come on
Bad connection to starter- ground strap on engine and large red wire going to starter
Bad ignition switch- kind of hard to check, but it's possible
EWS malfunction- The antenna, key, EWS computer, or DME could all be faulty.

I'm leaning toward a bad EWS antenna or bad key since it has to sit for a while and then starts fine. If you have another key, just try it and see if the problem goes away.
Good info.

So to clarify. First thing in the morning (and occasionally in the evening if I've been at work with the car sitting for 10-12 hours) turning the car to ACC or ON everything works, but continuing to the START position will not engage the starter to fire the motor.

After a few minutes, turning the key to the START position will engage the starter to fire the motor and the engine will then crank and run normally.

To further clarify, that first key turn to START each morning results in exactly nothing from the engine.
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Old Fri, Feb-10-2017, 07:46:22 PM   #6
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

Quote:
Originally Posted by Roofus View Post
Good info.

So to clarify. First thing in the morning (and occasionally in the evening if I've been at work with the car sitting for 10-12 hours) turning the car to ACC or ON everything works, but continuing to the START position will not engage the starter to fire the motor.

After a few minutes, turning the key to the START position will engage the starter to fire the motor and the engine will then crank and run normally.

To further clarify, that first key turn to START each morning results in exactly nothing from the engine.
Right. It's most likely a bad ignition switch or something with your EWS. Or a bad ground strap.

Try another key and see if that helps. That's the easiest thing to do. Then check the ground strap. That's the next easiest. Then either the EWS system or ignition switch. Both are kind of a pain but not terrible.
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Old Fri, Feb-10-2017, 11:07:31 PM   #7
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

Quote:
Originally Posted by kevinwilly View Post
Right. It's most likely a bad ignition switch or something with your EWS. Or a bad ground strap.

Try another key and see if that helps. That's the easiest thing to do. Then check the ground strap. That's the next easiest. Then either the EWS system or ignition switch. Both are kind of a pain but not terrible.
Only got 1 set of keys from the PO. I'll have to start with the ground strip.
Someone on bimmerforums said I could turn the key to START and hold it there doing nothing and have a second person pop the starter solenoid with a wrench to see if it came to life. Ever heard of doing that?
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Old Sun, Mar-12-2017, 04:07:30 PM   #8
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Default Re: Car won't cold start - fuel pressure, starter, or cam sensor?

Just coming back in to let everyone know it was the starter. Popping the starter with a wrench or putting the car in gear and rocking it back and forth would loosen the jammed tooth in the starter and it would crank back up. Removing it showed that there was a filed down tooth that was jamming into the flywheel and preventing startup. Thanks for all the help guys!
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Discussing Car won't cold start - fuel pressure, starter, or cam sensor? in the E36 M3 (1992-1999) Forum - {Euro - S50 B32 321hp @ 7400 rpm} {U.S. - S52 B32 240 hp @ 6000 rpm}
Total Produced: 71,212 - Years Produced: 1992 to 1999 at BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)