Long crank time

[Jamery16]

Hello everyone, thanks for taking the time to read this and respond.

I have come across a 1992 325ic that seems to have been neglected. I'm not exactly sure what has been done to it in the past, but I'm know not much has been done.

I've noticed that it takes around 8 cranks before the engine finally starts. The first thing I though was the check valve causing the fuel to leak back to the tank, so I let the car sit with the key in the "on" position for 30 seconds to let the fuel pump prime. I turned the key but the long cranking was still there. Next I thought fuel pressure, so I hooked up my trusty Snap-On gauge and jumped the fuel pump relay following the Bentley procedure. In a fraction of a second the gauge shot up to 300 kPa, or 143.51 psi, which according to the Bentley is damn near perfect. I let the gauge sit for 20 minutes and the pressure was still at 300, so for me this crosses out the FPR, fuel pump, check valve, and any sort of loss of pressure in the fuel system. Should I have let the gauge sit for longer than just 20 minutes?

I also checked compression, because the car seems to have a misfire when it gets hot, and the compression reads (from 1-6) in psi: 149, 160, 157, 150, 160, 160. I did all these as a dry compression test and I saw no reason to do a wet test since these read fairly good.

So what I'm thinking is that the car needs a new ignition system (cap, rotor, wires, plugs). Compression and fuel delivery are good so the only thing i can think of is the ignition system is poor.

I have also read about how messed up timing can be the cause of a long crank. Any thoughts on that?

So what I'm asking is if anyone has any knowledge or experience with this type of situation, can you please lend me some advise?
Also, if anyone has any ideas as to what would cause the misfire when the engine gets hot I would appreciate those ideas too.
I have cleaned the ICV and the entire throttle body and replaced the O2 sensor.

Thank you all so much!

[dohcdoh]

Do you have intake leaks?

[Jamery16]

That's a good question. I have been meaning to smoke test it but I just haven't gotten around to it.
I'm familiar with the method of spraying carb cleaner or brake cleaner all over as a way to test for leaks but I think it'd be more accurate to use a smoke tester. Do you know where a good spot for hooking the smoke machine up would be?

[richardodn]

The fuel system will not prime. Fuel pump is controlled by the ECU and it doesn't turn on the pump until it sees timing data from a cranking engine. However your other test with the gauge shows a leaky fuel system isn't likely the issue.

[my1stE30]

what do you actually mean when you state... "... it takes about 8 cranks before the engine finally starts ..." ,,, What is a crank..?

also, when you state that messed up timing might be the cause of a long crank ... how long do you have to crank this engine for it to start?

[Jamery16]

By "crank" I mean starter cranks so each of those "eee, eee, eee" noises.

[dohcdoh]

By "crank" I mean starter cranks so each of those "eee, eee, eee" noises.

Such scientific.

[my1stE30]

.... maybe your "long crank" is just normal for a M20 engine, but if you think it takes longer to start than the next M20, the issue is likely air intake leaks.

.... my chevy truck Vortec engine fires up instantly when I turn the key, but my M20 always takes a few seconds of cranking to fire up ... the BMW M20 engines have an ignition and fuel system that is different from north american and japanese cars so maybe you are comparing your long crank to the wrong reference,

[dohcdoh]

Do you guys know how long a few seconds is when you're cranking your engine?

[frostedE30]

From cold starts it takes about 3 seconds for the engine to fire up, about a second when warm.

[jagerking]

From cold starts it takes about 3 seconds for the engine to fire up, about a second when warm.

My brother's late E30 (B25) does this. My early M20 (B27) is the opposite; on cold starts, it needs one revolution of the starter. On warm starts, it usually needs 2-3 seconds of cranking before it'll start.

[Lints]

How about the main ground strap? Might want to replace it anyway, it's a cheap part and only two bolts. Bad ground can cause the starter to have to really labor to crank the car

[Jamery16]

Thanks I'll check the ground strap and the intake leaks when I have the chance. Does anyone know the best way to hook the smoke tester up?