M20 has spark and fuel, but just cranks?

[7pilot]

Get the engine to run as long as possible.
When it finally stalls, pull all the spark plugs to check what the fueling looks like.
Is it stalling due to over fueling or insufficient fuel?

Does it run long enough from stone cold until about the time that closed loop kicks in?
It is missing randomly when it does run, based on your description, so I think you may be getting too much fuel.
A plug read would refute or verify this issue.
If the plugs are fuel wet, what injectors is the engine using?

m

[7pilot]

Pull the plugs and tell us what they look like if you get the thing running for a minute or two.
What size injectors are you running?, stock, 17, or 19Lb?

m

[Jean]

It's all stock, heading out shortly to see if it's the c191 or if it's possibly the fuel pump. Will report back.

[87_black_325is]

I'm having a similar problem, after doing the head gasket from hell..

Have fuel and spark, engine cranks, but won't start and backfires. I was told it must be 180 out of time.. Long story short rechecked to ensure it was at TDC on compression (Cyl. 1). Then I checked the rotor/cap alignment. The rotor is not firing the #1 cylinder at TDC, Cyl 1.

When I had it apart it appeared that there was only one way it could go, because it had a little recessed niche where it fit.

Only two things I'm thinking right now are: 1) Recheck timing, ensure that it's not one tooth off. 2) Try rearranging the plug wires to fire in the correct firing order per BMW specs, starting with the point it's currently at.

I'll let you know what I figure out.

[jlevie]

The engine, cam, and spark timing will be correct when the crank is at TDC on the mark and the cam sprocket is on the mark. At that point the numbers on the distributor cap will be correct for the wires. There is a TDC mark on the crank hub that can be seen when the harmonic balancer isn't on the car. Check the timing using that mark and then fit the harmonic balance and see if it's mark also aligns. While not common, if the harmonic balancer has separated the timing disk can shift.

[Jean]

It's all stock, heading out shortly to see if it's the c191 or if it's possibly the fuel pump. Will report back.

c191 was fine. It was a fuel pump issue in my case.

[lolcantturn]

c191 was fine. It was a fuel pump issue in my case.

How did you determine that? jumped the fuel pump relay and nothing happened ?

[Jean]

Well, everything else in my case checked out fine and I was down to fuel delivery issue. I removed the pump and replaced with another, all problems went away.

The pump in the car was only able to get the car running after it sat for hours, and any throttle input would cause it to idle bad/die and wouldn't re-start the car.

[87_black_325is]

Problem in my case was that the rotor itself was legitimately 180 degrees out of time. I didn't realize that it could fit on more that one way, but in fact it will.

Car is running now.