P38 Fuel pump

Hello,

Could someone tell me please how to check if the fuel pump has given up the ghost on my car. (1998 p38 tdi)

There is no fuel getting to the injectors.

Should there be a sound comming from the fuel pump if its working?
Is there one or two pumps?
Is it easy to clear any blockage if there is one?
Is it a difficult job to change fuel pump?


Thank you for your help.

Mike.

take the pipe of that comes out the the fuel filter and then turn the ignition on, you should have a nice flow for a few seconds while the pump in the tank primes. next i would check power on the fuel solinoid valve on the back of the main injection pump, with the ignition on you should see battery voltage. sometimes they just need re syncing although ive never had that particular problem although plenty on here have.

The intank fuel pump will only come on for a few seconds when you turn the ign on to prime the system. It doesn't keep running until the engine starts. How much fuel is in your tank? You can normally still start and run the diesel with a knackered intank pump but only if the fuel level is above around a quarter full. Lower than that and the pump on the engine will not suck it through.
Common faults on the intank pumps are pump motor failure and the pipe coming off between the pump and the mounting plate. There's an excellent thread on here by 'Canyon' on how to cut a hole in the boot floor to access the pump without having to drop the tank. Another common failure is the fuel pipe where it comes out of the tank.

THE BUDDAH said:

Hello,

Could someone tell me please how to check if the fuel pump has given up the ghost on my car. (1998 p38 tdi)

There is no fuel getting to the injectors.

Should there be a sound comming from the fuel pump if its working?
Is there one or two pumps?
Is it easy to clear any blockage if there is one?
Is it a difficult job to change fuel pump?


Thank you for your help.

Mike.

Click to expand...

Check fuse 39 pump relay fuse is not blown 10 amp upto MY1999. 1999 and on 20 amp. Remove pipe from filter. Place in a suitable measuring container. Remove relay 12 from fuse box under bonnet. With ignition switched OFF. Bridge a + wire from battery to terminal 5 on relay socket for ten seconds. Terminal 5 is the one that is directionally contrary to the other three. You should get 180 ml of fuel minimum flow within that time span.

Derek Ward said:

The intank fuel pump will only come on for a few seconds when you turn the ign on to prime the system. It doesn't keep running until the engine starts. How much fuel is in your tank? You can normally still start and run the diesel with a knackered intank pump but only if the fuel level is above around a quarter full. Lower than that and the pump on the engine will not suck it through.
Common faults on the intank pumps are pump motor failure and the pipe coming off between the pump and the mounting plate. There's an excellent thread on here by 'Canyon' on how to cut a hole in the boot floor to access the pump without having to drop the tank. Another common failure is the fuel pipe where it comes out of the tank.

Click to expand...

Changing the in tank pump is a dawdle. If I can do it anybody can. I had to cut a hole in the floor of the boot to get at it. Posted some pics.

I just changed mine, hardest part was summoning up the courage to cut that hole, guidence here http://www.landyzone.co.uk/lz/f10/tank-fuel-pump-template-p38-109368.html after that no problems.

Thank you.

I'll try

Mike.

Hello all,


There is no fuel in the clear pipe that goes to the injector pump.

Isn't it dangerous cutting a whole in the floor pan so close to the fuel tank?

I tried to syphon out the deisel with a syphon pump but it did not work, is there a drain off point for the fuel?


Thanks

Mike.

THE BUDDAH said:

Hello all,


There is no fuel in the clear pipe that goes to the injector pump.

Isn't it dangerous cutting a whole in the floor pan so close to the fuel tank?

I tried to syphon out the deisel with a syphon pump but it did not work, is there a drain off point for the fuel?


Thanks

Mike.

Click to expand...

Only if you do it with a welding plant. No drain. Diesel is pretty difficult to light. Just go steady. Did you do the pump test as i suggested? There is not much point in asking for advice and not following it.

How much fuel have you got in the tank? A lot of the posts on here that result in cutting a hole in the floor and changing the pump are because the vehicle is difficult to start when the fuel is low. If the pump is weak or knackered with plenty of fuel there is at least a degree of gravity feed. If the fuel is lower than about quarter tank mine was beginning to struggle to fire, more fuel resulted in easy starting!
If you do have to change the pump just follow Canyons instructions/measurements and you should be fine. I was a bit concerned when I cut my floor recently but needn't have worried. As long as you follow Canyons measurements exactly there should be no problems.

Hi wammers,

I will try the fuses tonight if it's not too dark after work and I can figure out which fuses do what.
I did notice that there was no fuel in the clear tube that leads to the injection pump and I did look at the fuel feed to the filter but could not see how to get the metal clip off and did not want to force it. I may try tonight.
I bougt a syphon kit to remove the diesel but that was useless and I have half a tank full.

Let's hope it is the relay.....and a simple fix.

I don't really want to cut the floor..

And once again thank for you help.

Mike.

Thank you enery8

I'm hoping not to cut the floor but it might be the only way I can get the thing moving.

Mike

THE BUDDAH said:

Thank you enery8

I'm hoping not to cut the floor but it might be the only way I can get the thing moving.

Mike

Click to expand...

its not the only way, theres always the option of dropping the tank and doing it the proper way. i did mine (when i had one) and it dont take long to drop it, you can have the tank off in an hour.

arron beast unleashed said:

its not the only way, theres always the option of dropping the tank and doing it the proper way. i did mine (when i had one) and it dont take long to drop it, you can have the tank off in an hour.

Click to expand...

Thanks arron,

The thing is im having trouble emptying the half a tank of deisel thats in it, don't want it falling ontop of me...lol

Mike.

I need to get this sorted so i can use the car to tow my off roader to a trials event, they always go wrong at the wrong time...lol

I would just like to say thank you to:

Wammers.
Arron beast,
Derek ward,
Takdrivers,
Enery8.

For all your help and advice.
Yippeeee....my car is running, though it was not all straight forward.
Tried bridging relay...no luck.
Tried new relay...no luck.
So went all in and cut a hole in the floor changed fuel pump.
It was difficult getting the rubber seal to fit around the pump opening but got there in the end.
I left the fuel pipe off at the filter end and placed it into a container then turned the car over a few times to bleed the pipe.
once the pipe was bled i conected it back to the filter.
Turned the ignition a few times and voila........engine was running again.


Also a big thank you to canyan for putting the cutting instructions on the site.

Mike.

PS ITS MY BIRTHDAY TODAY......................LOL

well happy birthday. I'm sure your rr will have another little present for you soon

happy birthday mate, glad you got it sorted.

these posts mirror my p38. problems; can anyone tell me how many amps the fuel pump needs. is 4.5amps enough.
Does the fuel line on the 4.6 petrol version need to be bled? after removing pump, which turned out to be ok.
Still not getting fuel, so all we get is a few beats, a cough, splutter then dies.
My 6 wheel Classic burnt out. Write off. Insurer would not pay out saying the small print did not cover a car over 25 years old for fire. They still took my premium for several years before though.
My 4.2 Classic 4 door Overfinch conversion still sitting in garage waiting for a miracle.
I think I have to dispose of all three as I am too old for the brand. Sad to say.

6wheelsup said:

these posts mirror my p38. problems; can anyone tell me how many amps the fuel pump needs. is 4.5amps enough.
Does the fuel line on the 4.6 petrol version need to be bled? after removing pump, which turned out to be ok.
Still not getting fuel, so all we get is a few beats, a cough, splutter then dies.
My 6 wheel Classic burnt out. Write off. Insurer would not pay out saying the small print did not cover a car over 25 years old for fire. They still took my premium for several years before though.
My 4.2 Classic 4 door Overfinch conversion still sitting in garage waiting for a miracle.
I think I have to dispose of all three as I am too old for the brand. Sad to say.

Click to expand...

How did you test the pump.