M50 Manifold Cold Startup Issues

Crazyfool · Tue, Apr-21-2009, 08:45:29 AM

I have done several searches on this issue, but I couldn't find any solutions.

I have an E36 M3 with an M50 manifold. When the engine is cold, it takes about 3 cranks for the car to start up. I am guessing that it's losing fuel pressure somewhere, but where? I have already checked for leaky injectors, vacuum leaks and broken check valves.

Has anyone found a solution to this problem yet?

TheM · Tue, Apr-21-2009, 01:49:18 PM

Sounds like a vacuum leak. Check for any hoses that you may have forgotten to connect.

Crazyfool · Tue, Apr-21-2009, 10:32:20 PM

Quote:

Originally Posted by TheM

Sounds like a vacuum leak. Check for any hoses that you may have forgotten to connect.

I've already checked all vacuum lines, and there's not a single leak anywhere.

Any other ideas?

TheM · Wed, Apr-22-2009, 01:02:50 AM

Quote:

Originally Posted by Crazyfool

...I am guessing that it's losing fuel pressure somewhere, but where?..

Put a fuel pressure gauge in the system and find out for sure.

Are you getting any CELs or codes?

EauNatural · Wed, Apr-22-2009, 04:12:22 AM

Did you just install the M50 manifold? or did this problem just come about abruptly?? A bad/clogged fuel filter caused my old E46 to act like this only when cold ONLY. (needed 2 cranks). I had the car smoked too thinking it was a vacuum leak but nada..

Crazyfool · Wed, Apr-22-2009, 06:00:27 AM

Quote:

Originally Posted by TheM

Put a fuel pressure gauge in the system and find out for sure.

Are you getting any CELs or codes?

I already did a pressure check with a gauge. It does drop a small amount, but nothing that would explain why it takes exactly 3 cranks to start up.

Quote:

Originally Posted by EauNatural

Did you just install the M50 manifold? or did this problem just come about abruptly?? A bad/clogged fuel filter caused my old E46 to act like this only when cold ONLY. (needed 2 cranks). I had the car smoked too thinking it was a vacuum leak but nada..

This started happening the second I installed the M50 manifold.

m3_858 · Wed, Apr-22-2009, 06:32:23 AM

Quote:

Originally Posted by Crazyfool

I already did a pressure check with a gauge. It does drop a small amount, but nothing that would explain why it takes exactly 3 cranks to start up.

This started happening the second I installed the M50 manifold.

How did you install the m50 mani? Kit if yes which one, home made rig? Also I remember having to disconnect something from the starter if I recall right, maybe you messed something up during the install. Can you be more specific.

Crazyfool · Wed, Apr-22-2009, 06:50:23 AM

Quote:

Originally Posted by m3_858

How did you install the m50 mani? Kit if yes which one, home made rig? Also I remember having to disconnect something from the starter if I recall right, maybe you messed something up during the install. Can you be more specific.

I installed it like you would install any manifold.

It's my understanding that this is a common issue with the M50 manifolds. Hasn't anyone found a solution for this yet?

m3_858 · Wed, Apr-22-2009, 06:53:32 AM

Quote:

Originally Posted by Crazyfool

I installed it like you would install any manifold.

It's my understanding that this is a common issue with the M50 manifolds. Hasn't anyone found a solution for this yet?

You can't just straight install m50 manifold on s52. Maybe that's your problem

You need a kit of some kind or something home made to accommodate for all the differences between the m50 and whatever the hell the 96+ manifold's called. I've used the eurosport kit, most people don't want to spend the extra money and go with eric's kit, some get all homedepot made parts and do it themselves. It's not a direct swap so I don't know what you're talking about.

Crazyfool · Wed, Apr-22-2009, 07:10:43 AM

Quote:

Originally Posted by m3_858

You can't just straight install m50 manifold on s52. Maybe that's your problem

You need a kit of some kind or something home made to accommodate for all the differences between the m50 and whatever the hell the 96+ manifold's called. I've used the eurosport kit, most people don't want to spend the extra money and go with eric's kit, some get all homedepot made parts and do it themselves. It's not a direct swap so I don't know what you're talking about.

The M50 came with all necessary parts for the installation.

Tue, Apr-21-2009, 08:45:29 AM	#1
Crazyfool Littering and? Join Date: Sep 2007 Posts: 652 Reputation: 0 Location: Los Angeles	M50 Manifold Cold Startup Issues I have done several searches on this issue, but I couldn't find any solutions. I have an E36 M3 with an M50 manifold. When the engine is cold, it takes about 3 cranks for the car to start up. I am guessing that it's losing fuel pressure somewhere, but where? I have already checked for leaky injectors, vacuum leaks and broken check valves. Has anyone found a solution to this problem yet? __________________ M3 — Carbon Black — SMG — Cinnamon Yamaha R1 RX-7 FD3S R1 — 504 RWHP — 11.318 @ 129 — video

Wed, Apr-22-2009, 04:12:22 AM	#5
EauNatural Registered User Join Date: Jun 2007 Posts: 626 Reputation: 0 Location: NYC	Did you just install the M50 manifold? or did this problem just come about abruptly?? A bad/clogged fuel filter caused my old E46 to act like this only when cold ONLY. (needed 2 cranks). I had the car smoked too thinking it was a vacuum leak but nada.. __________________ E36 ///M3/4/5 Arctic Silver on Black - The Latest & Greatest E46 ///M3 Carbon Black on Black - The Former "If you haven't tried, you haven't lived"

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Tue, Apr-21-2009, 01:49:18 PM	#2
TheM Registered User Join Date: Dec 2007 Age: 46 Posts: 1,281 Reputation: 0 Location: Orlando	Sounds like a vacuum leak. Check for any hoses that you may have forgotten to connect.