Fuel lift pump.

[t4magic]

To help me fault find why my truck wont start can anyone explain how the fuel pump works.

I assume there is a lift pump in the tank, goes upto the filter, out the clear hose to the injector pump, and back to the tank, via the filter through the blue hose ??

My problem is i am not getting any fuel come through the clear hose. so i assume it is the lift pump not working or blocked somewhere?

I checked fuse 18 which i believe is the fuel pump fuse??

Is there a fuel pump relay somewhere to check?

1999 AJT 2.5 TDi.

Thanks in advance.

[t4magic]

I'v sorted it now. Appears there is no lift pump on these... i primed the filter with fuel and it filled the line after a few go's on the starter. Seems the Injector pump holds the lift pump too? and it draws the fluid up from the tank.

Please correct me if i am wrong.

[T4 VIRGIN,]

Originally Posted by t4magic

I'v sorted it now. Appears there is no lift pump on these... i primed the filter with fuel and it filled the line after a few go's on the starter. Seems the Injector pump holds the lift pump too? and it draws the fluid up from the tank.

Please correct me if i am wrong.

im sure there is an auxilliary pump unit on the sender unit ??? a lot of people may be away at shows etc this weekend so you may not get a definete answer soon,if you are confident shes bled and timings spot on give it a tow ???

[t4magic]

Ok thanks.

Im sure the fuel is getting there now as the glow plugs came out wet.....

Now its just the timing. Cam belt is 100% double checked it and used the correct timing tool and feeler gauges.

Its the pump timing that may be the problem. I dont have a DTI so i have aligned it to the mark on the housing, which is a bit vague to be honest.

I wonder is its possible to use a vernier in the DTI timing port? or should the timing be OK ( to get it to start, but probably run poor) when done by eye using the alignment marks on the pump housing and pulley ?

Cheers!

[trism286]

theres no pump in the tank on a diesel.
good luck with the timing as i think you need a laptop for the 2.5's

[t4magic]

Ok cheers.

All sorted now! Just got it running for the 1st time!

Managed to get my digital vernier in the end of the Injection Pump and set the timing that way.

The mark on the pump housing is a good 5 - 10 Deg out of what the actual position is when set to 0.55mm lift on the vernier in the DTI port.

Yeh you do need VagCom to fine tune it. But you really need a DTI or vernier to get the pump to a setting where the engine will start, and then fine tune it with VagCom once the engine is warm.

Thanks for your help guys!