Bulletin for long crank times

[dan90rs]

Several times I've seen a bulletin for long crank times but I've never been able to find the actual content of the bulletin. Does anybody know what it consists of? Or where I can find it?

I get a very intermittent long crank time problem. I can go a week and it won't happen at all sometimes. Car runs great afterwards.

[KC Ron Carter]

Fuel pump check valve.


I could replaced the fuel pump for $200 but I fixed the problem by putting in the fix from BMW for about $3.50,
part # "16 14 9 068 988"

Now the engine starts on first turn, hot or cold, overnight or after
standing for a while.

Diagnosis:

The check valve in the main fuel pump was leaking allowing the fuel injector rail residual pressure to bleed off resulting in formation of a huge fuel vapor bubble in the fuel rail and back down the fuel line toward the pump.

The extra cranking time was needed by the fuel pump to recompress and
eliminate the fuel vapor bubble in the line and repressurize the fuel injector rail.

Installation can be anywhere in the fuel pressure line but next to the main pressure pump is best.

It is a two screw clamp job.

Later,

[500kE30]

I used to have the long crank problem, it happened only when the engine was cold. Replaced the thermo timing switch, starts like a champ all the time, no matter what the temp is outside.

[dan90rs]

Ron,

In my experience, when the fuel pump check valve goes bad, it's done. There is no intermittent failure. However, my condition is very intermittent.


It always starts up on cold starts. It tends to act up when it's been sitting for like 30-60 minutes. If it's been sitting for less or more than 30-60 minutes it fires right up.

[Bimmubishi]

I have the same problem. Wondering if anyone has suggestions when the long crank times seem to be more related to warm starts. I'm ordering that above valve just to eliminate that as a potential issue.

Alex

[robmpulse]

I have this problem when I try to crank the car, and don't hold the key long enough. Usually because my fingers slip off the key.

My car always starts fine. It's only operator error when it doesn't start. But once that happens, the second attempt always takes about 10 seconds to get it started.....

[Alpine003]

I used to have the long crank problem, it happened only when the engine was cold. Replaced the thermo timing switch, starts like a champ all the time, no matter what the temp is outside.

Mine has a hard time starting cold. Can you elaborate on the thermo timing switch?

[mreloc]

Ron,

It always starts up on cold starts. It tends to act up when it's been sitting for like 30-60 minutes. If it's been sitting for less or more than 30-60 minutes it fires right up.

I have the exact same issue...

[digger]

injectors could be faulty which was what i was experienced. Pressure bleed off is bogus IMO you'd need a massive leak for you to need to crank several times to build up pressure. My car starts perfect when the pressure is <5 psi. For instance the pressure goes from <5 to 45psi in less than 0.5sec.

[greese]

Just order part #16 14 9 068 988 from Pelican. Will let you know if it works. I've had this problem since I got the car.

[dan90rs]

injectors could be faulty which was what i was experienced. Pressure bleed off is bogus IMO you'd need a massive leak for you to need to crank several times to build up pressure. My car starts perfect when the pressure is <5 psi. For instance the pressure goes from <5 to 45psi in less than 0.5sec.

n/m

[bmwQUEBEC]

long crank time when warm (more than an hour but less than 5 befor the engine was stopped) can be caused by leaking injector while the engine is not running. a too rich mixture will be hard to light, the plugs can get fooled, the cylinder walls get washed up of oil causing the compression to go down.

[500kE30]

Mine has a hard time starting cold. Can you elaborate on the thermo timing switch?

It's located on the top of the engine towards the front right next to the coolant temperature sensor. Relative to the coolant temp sensor, it more left (driver's side) and closer to the front of the car. Check out the picture on page 6-26 in the bentley manual.

[StackTrack]

Subscribing to find out what happens

[Alpine003]

It's located on the top of the engine towards the front right next to the coolant temperature sensor. Relative to the coolant temp sensor, it more left (driver's side) and closer to the front of the car. Check out the picture on page 6-26 in the bentley manual.

Thanks but I'm not so sure I have on on my m42, at least not in the location you are describing.

[500kE30]

Thanks but I'm not so sure I have on on my m42, at least not in the location you are describing.

sorry I don't know anything about M42s