Fuel Pump w126 300se 1988

[spacemoc]

What is responsible for shutting down Fuel Pump in w126 300se 1988? is it a Fuel Distributor or ECU? My fuel pump goes on and on all the time, fuel consumption is massive! Any Advice? Thanks

 

[television]

Pull the fuel pump relay and see if it stops, it is the CPS that tells the pump to work, surplus fuel should be returned to the tank.

You can check by just turning the key to ignition where the pump should run for a few seconds and stop

 

[spacemoc]

yes I can hear the noise once key is turned, then noise stops. but once driving fuel pump is on all the time. I will take out fuel pump relay let see what will happend

 

[television]

I would say that it is normal then, it will run all the time when running, you might have a fault in the pressure regulator

 

[spacemoc]

car stops after I pulled relay

 

[spacemoc]

once connected to Bosh Computer reading is very high, mixture is to rich, do you think so i should change fuel distributor (metering unit)?

 

[television]

It is more involved than that,, the pressure needs to be checked, you could have a leaking injector or an air temp sensor could be giving false info leaving some fuel enrichment engaged from a cold start

 

[spacemoc]

thank you for this useful advice, will do all the checks and update this post once ready.

 

[television]

I do have the complete injection spec and I can give some more info later

 

[spacemoc]

if you don;t mind, yes please. Or shall I do diagnostics first? you can send me on info@mocit.co.uk, please

 

[television]

Take down your address for now,, I have to find some way to copy it all

 

[syncropaddy]

I was warned of a sensor fitted to the back of the engine that can cause all sorts of hassle with fuel consumption, starting, idling etc. So I carry a spare.

 

[television]

I was warned of a sensor fitted to the back of the engine that can cause all sorts of hassle with fuel consumption, starting, idling etc. So I carry a spare.

That is all it takes and the easiest thing to check

 

[spacemoc]

do you know the name of that sensor? so i can get one. But I think so i should run full diagnostics on my car using Bosh Equipment in the first place, what do you think so?

 

[television]

With any air temp sensor just shorting it to ground (single wire type) will put the engine in the hot made, taking the wire off will put it in the cold mode