car cranks for a long time sometimes

[niq_nak]

every now and then it will take my car a really long time to start. other times it starts within half a second of when i turn the key. it doesnt do it on any occasion either, ive had it start right up after sitting for over a day and ive also had crank for a long time after it only sitting for around 45 minutes. anything i should check out?

[Spaz]

Re: car cranks for a long time sometimes

every now and then it will take my car a really long time to start. other times it starts within half a second of when i turn the key. it doesnt do it on any occasion either, ive had it start right up after sitting for over a day and ive also had crank for a long time after it only sitting for around 45 minutes. anything i should check out?

common problem, i actually figured this out the other day.
if my asumsations are correct.

bmw fire the injectors according to the pulse sensor. And the computer looks for #1 cylinder before it starts the squence for the injectors, so therefore if #1 is just past the pulse sensor or on it, then it won't fire for that whole revloation of the engine...untill it see's #1 again, then the firing squence is started..and the car will start.

i believe this is true to what my findings are....i know this is true for hondas though.

hth

-cam

[shields]

really? interesting...I have the same issue...

[modbimmer]

it seems that this is a common issue with e30s. if i start my car cold, no problems. if i start after ive been driving around for a while then ill have this long cranking. sometimes it starts, sometimes ill release the ignition and try again with some throttle. in any case, the car always starts. so now worries. ive heard lots of theories from other forums but there has not been an obvious solution. one bmw tech said something about a one way valve in the fuel line/system. another said it may be "leaking" fuel injectors. i think some bmw engineer who designed the e30s did it to piss us off.

[Axxe]

My car does the same thing. Kinda weird, but at least it always starts.

[DaN]

It may also have something to do with the cold start injector, if the engine is cold (below the temp required to fire it) then the engine may start up faster with the extra burst of fuel.
If it's hot, the cold start won't fire, and there also maybe some vapor in the fuel lines.

This is my rationale...

[SebSter]

same thing happens to me, doesnt fail to start, but every once in a while takes it a bit longer.. i was worried till I read a few months ago that its a common thing on e30s and not to worry about it.

as long as it does eventually start, no problems..may put a bit more wear on the starter tho, but what can u do. I haven't yet read or heard of a proper fix for this on the e30s.

[Brew]

It may also have something to do with the cold start injector, if the engine is cold (below the temp required to fire it) then the engine may start up faster with the extra burst of fuel.
If it's hot, the cold start won't fire, and there also maybe some vapor in the fuel lines.

This is my rationale...

The m20b25 doesn't have a cold start valve. :idea:

[Axxe]

On later cars there is no cold start injector, the six regular injectors simply dump more fuel.