Once in a while my 240 1991 engine wont start. It almost does sometime but seem to die out of gas. Sparks seem there. Car always started after 5 to 30 minutes up to now but this is happening now 25% of the time. Fuel tank level is about 1/3 at the moment.

I have tested fuel pump relay by wiring a pilot light on fuse #4. When I turn ignition on the pilot light stays on for about 3 seconds and goes off. I can hear a fuel pump going for 3 seconds. This sounds normal given the system does build up pressure and waits for starter to be turned on. Safety precaution I beleive.

I wonder if what I hear is the main fuel pump.

Could the in-tank pump be the problem?

Could not happen in a worse time; my brother's RV is in the driveway and he has my old 1982.

Thanks for your help.

Rob, Dave and Hugh,


Thank you for your help.

I found a loose connector on the main fuel pump wire. I must say that I installed a homemade anti-theft device which consist of a relay that cuts voltage on the main fuel pump when activated. I put yhat relay near the wiper motor ralay under left foot. It had a loose wire connection and sometime current would not pass.

All this made me do a little study which is good.

Replace or re-solder the fuel pump relay. I just had to do this in my 91.
If there's no improvement,plan on replacing the engine speed sensor (aka crank sensor or RPM Sensor).
IF it does eventually start with continued cranking, it could also be the fuel pump check valve.
Good luck!
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Rob Bareiss, New London CT ::: '86 244DL- 215K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K

Rob,

The fuel pump relay has been re-soldered and I did try with a second one which I beleive good.

The speed sensor was replaced last year and has only 3k miles on it.

I take note of your suggestion about the fuel pump check valve.

If I jump fuse 4 and 6 I suppose the fuel pumps will run all time. Will this sort of eliminate the effect of a bad FP check valve?

I was also thinking of somehow injecting fuel with a small bottle; I think it should start temporarily confirming that it only need fuel.

I will toe this car home with my old 240 1982 tonight when it is dark. It is about 1000 ft from the driveway. I am too cheap to call and pay a towing...


Thanks for your help.

The rubber sleeve that connects the intank fuel pump to the fuel line could be comming apart. This means that sometimes it will start, and sometimes it will not. Hugh Sr.

If you disconnect the connector for the Mass Air Flow Meter will it start. Have you changed the fuel filter. Mine was doing the same until i changed the fuel filter.

Hugh and Dave,

I got your suggestions about in-tank pump and replacing fuel filter. I will go ahead with these for sure.

I though that if I disconnect the air mass meter the car would start in limp-home mode only, which means it could run at idle. Would a connected air mass meter that is defective prevent the engine from starting, but let it start with AMM disconnected?