S50 starts but won't stay running

[slo325i]

EWS wouldn't even let it start

[Danny]

I pulled off the brake booster vacuum line and it seemed to run better WITH a vacuum leak than without.

[Wh33lhop]

I was thinking possible weak fuel pump too. Although it's been said that the M20 DME doesn't prime the fuel pump, I know for a fact that my NV's 403 does. If you've got fuel pressure built up from a prime but the pump can't retain pressure with any real flow, well then you have a similar situation to your own.

Just a thought.

[Danny]

One time my car died when it was real hot out and I was low on gas. Doesn't that point to a failing pump?

[BenM]

Fuel Pressure Regulator?

I was gonna say, sounds like it could be that.

Yeah, pretty sure CPS is out since the car won't run if its bad.

[BenM]

One time my car died when it was real hot out and I was low on gas. Doesn't that point to a failing pump?

It's possible, but it could have also been vapor lock.

[Danny]

I was gonna say, sounds like it could be that.

Yeah, pretty sure CPS is out since the car won't run if its bad.

Well I ordered a new fuel pump. Seems to make more sense to me.

[Farbin Kaiber]

No danny, it does not. You never had a fuel pump issue with the m20, but put in a new engine with a different pressure regulator, I'll bet it is the regulator before it's the pump. Don't pull a Japandrew.

[Danny]

Well wtf the regulator is on the rail right? Its one piece yeah?

[Farbin Kaiber]

Yep. Chances are the engine you got sat, and the diaphragm in the regulator dried out and became brittle, lil bit of pressure, and that thing just shit the bed.

[Danny]

I drove it for 3000 miles before it shit the bed though?

[Danny]

Fixed it lol

[gobuffs]

EWS wouldn't even let it start

I've never had an EWS issue, but it is my understanding that the car starts and runs for a second or 2 then dies.

[nrubenstein]

So what was it?

[Farbin Kaiber]

He won't tell cuz it was something really lame, like a vac hose on the FPR.