The car was starting regularly with no issues. It usually started on the first try. Today it cranks but no start. I replaced the combo relay about a couple months ago when i had the same issue and that solved the problem then. Is it possible that it is the same problem again? again? Can a fuel injection engine "flood" like a carburetored engine can from too much cranking? What is the best way to isolate the problem?
Karl
Crank but No Start
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- Posts: 1058
- Joined: Tue Jan 06, 2009 3:50 pm
Crank but No Start
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
- Robert Bondi
- Posts: 348
- Joined: Sun Jan 11, 2009 12:33 am
- Location: Austin, TX
Re: Crank but No Start
I wouldn't say flooding, but as you attempt to start and are unsuccessful, the cold start mechanisms will be helping
you less. For example, the thermotime switch is warming itself with cranking, IIRC, and will be giving less of a shot of gas through the cold start valve through successive start attempts.
I always go back to the basics....fuel, spark, and timing. Timing shouldn't be an issue if the car was sitting.
A trick I frequently use on starting issues is to jump AFM pins 36 and 39. It's the safety fuel cutoff based on the AFM door. IT allows you to put the key in "ON" and hear the fuel pump running before cranking and gain reasonable confidence you have fuel pressure. IT also fully pressurizes the fuel system before starting.
you less. For example, the thermotime switch is warming itself with cranking, IIRC, and will be giving less of a shot of gas through the cold start valve through successive start attempts.
I always go back to the basics....fuel, spark, and timing. Timing shouldn't be an issue if the car was sitting.
A trick I frequently use on starting issues is to jump AFM pins 36 and 39. It's the safety fuel cutoff based on the AFM door. IT allows you to put the key in "ON" and hear the fuel pump running before cranking and gain reasonable confidence you have fuel pressure. IT also fully pressurizes the fuel system before starting.
Robert
77 530i
77 Euro 528
77 530i
77 Euro 528
Re: Crank but No Start
Yes you can flood an injected engine, I did it a couple of times on my first E12 when I had a cranky FPR. Since ignition and fuel are separate the solution was to unplug the ECU which left the ignition working, crank it and it would briefly start and burn off the excess fuel.
Mike W.
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter