First off, I own two MBs (both 300 diesels), but I was just given a 1996 Dodge Dakota P/U (4 cylinder fuel injected).

It starts right up for about 4 seconds and then dies. It will do it again, the same way. If I spray starter fluid in the intake, it will stay running for a few more seconds.

I have replaced the "upstream" O2 sensor and cleaned the throttle body and checked for obvious vacuum leaks...

ThE DODGE FORUMS suck for assistance!!! So, I need help figuring this out. I don't want to just randomly replacing sensors...that is too expensive. I want to get it running (it is in great shape otherwise), sell it, and pour the money into my MBs!!

ANY suggestions would be greatly appreciated.

Don

81-300sd - 215K
84-300d - 255K

Does it die if you floor it? If so, try idle control valve or mass air flow sensor.

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1989 300E 144K

could it be some kind of anti-theft immobilizer?

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TXBill



Former owner of a few diesel MB cars
1998 Lexus ES 300 In Chicago We Trust

The truck dies if I floor it or leave it alone. The service department said they thought it was the fuel pump (but they did not look at it), but it starts everytime....but only for a few seconds.

The truck was hit in the driver-side rear quarter panel (not that bad, though). Could it have activated the roll-over valve? Anyway, thanks for the insight, I will look at those items.

Don

Bill, The previous owner did not know of an anti-theft immobilizer. Would that be on it without them knowing about it? It does seem like a shut-off is killing it... It is like the kill switch on some motorcycles that cut-off if you didn't have the clutch in even if it was in neutral...

Don

Last month I walked home to find a stranger in a Chebby of some sort in my driveway. His car died on him (right in front of my house, as it were) and had the same symptoms. I tried all kinds of things, incl. tapping on the fuel pump, to no avail. I finally found the schrader valve on the end of the fuel rail, pressed it in 'til there was no more pressure, and the car started and ran fine. It was a shot in the dark but it worked (at least long enough to get him and his entourage out of my driveway, down the street, and around the corner -- hope they got home OK).

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1992 300D 2.5T
1980 Euro 300D (sadly, sold)
1998 Jetta TDI, 132K "Rudy"
1974 Triumph TR6
1999 Saab 9-5 wagon (wife's)

Check the fuel pressure and see if you can hear the fuel pump running. See if you can hear the injectors ticking, need stethoscope, or check them with noid light or test light. Check the fuses.

I believe you have a fuel delivery problem. Could be a clogged fuel filter or a fuel pump on it's way out or both.

For good measure I'd check spark and then compression to rule them out. If it's not one of those three, then it's engine management and will require a code reader to diagnose.

edit: check for vacuum leaks too, but that would make it run rough while idling

i had the same problem with a 96 caravan. replacing the fuel pump relay solved the problem. relay is located under the hood in a plastic box full of fuses and relays. cover should be indexed. after replacing relay pull ignition fuse for 20 seconds, replacing fuse initializes relay change to computer.

Thanks to everyone for the suggestions... I will try these tomorrow and report back.

Don

I switched out relays, etc.. and nothing. So, I pulled the incoming gas line off of the fuel rack and there is nothing...not even turning the engine over. No sound from the fuel pump... the engine will not start at all now.

Can this be a sensor or is it the fuel pump? The fuel filter is also in the tank. I will have to pull the tank...I have never done that before.

Any other suggestions? I don't want to pull the tank unless I know for sure.

How can I test the fuel pump without pulling it?

Thanks, Don

Could a bad crank position sensor do all of this? I hope someone knows, as the sensor is about $60.

Thanks, Don

See if power is getting to the fuel pump.

Get a service manual for any vehicle and the basics will be the same. See if you can get someone there to help you.

Don't worry about sensors until you get fuel pressure in the system.

Listen to the fuel pump in a working car. Compare it to the truck. When you turn on the key the fuel pump should run for a few seconds to pressurize the system. That is what you need now, get the fuel pump to run.

I'd be willing to bet Germanstar's house that it's the fuel pump. Change the filter while you're at it.

I THINK you can pull codes from them by turning the key from run to off three times, then turning it to run again. The check engine light should start blinking codes, pausing between them. You will need an Haynes manual with the list of codes. If no sensor codes are being displayed, then it is probably the pump or related wiring. Had a '94 Cherokee do then same thing years ago, it was the crank sensor on the back of the engine on the driver's side. It was a 4.0 six though.