OKsimpson

I have a question for the ones who know more about cars than I do.

I went into the ownership of W140 with no idea about the car.

It was not running and there was no hope in sight but I liked the looks of it.
After replacing the EZL nothing happened so I after messing with it I determined the fuel pump in it was rotten almost to the point to falling apart.

I bought the fuel pumps that you see on e-bay all the time 2 in one package, turned out that W140 has only one and it is longer and not as big in diameter. (apparently made for the cars with dual pump setup)

I made one of them fit anyway and ever since the car is running but my engine light stays on all the time and half of the time (especially when engine warm) it does not start after the first crank even if done for 5-8 sec. Second time it fires right up as it should.

I determined that the fuel pump does not have power as soon as the key is on like most of the american cars do to self prime the system till the normal pressure is reached in the lines.

The fuel pump circuitry does not get power untill I turn the key and crank the engine.

So either the pump I bought is less powerful than the one originally in the car and not delivering enough pressure or there is some sort of relay that is burned out on my car and it stops it from powering the fuel pump before cranking the engine.

Please let me know if you have any ideas, whether my theories are right or am I just making deductions without having a clue.

Thanks

P.S. Willing to buy a 95-99 front bumper if anyone got one available.

guydewdney

the fuel pump normally has a one way valve in it to maintain pressure... maybe yours is missing this?

OKsimpson

I'll look into that maybe (try to see if the dealers can tell me anything about it)
Thanks

shopcarpro

Your pump should run the instance you turn key on. You should hear it from under the car.
It will run few sec.s and stop if you stay in ON position. That is the time your system is getting primed and if its not happening you will not have correct fuel pressure to the injectors
to open. connect a fuel pressure gauge on to your fuel rail to verify this condition.

Peter Guenther

140s, have tandem fuel pumps, the relay is next to the rear fuse pump. When you turn on the ignition it pressurises the system, and will time out in about 10 seconds if the engine does not start.