Fuel supply issue, 2 Fuel Filters?

Last week my cabby cut out on the way to it MOT of all things. Took it back home to discover that no fuel is getting to the engine.

Ive recently replaced the fuel filter next to the metering head also the fuel pump is new.
I notice that the fuel pump was not running I replace the fusebox and relay.  This brought the fuel pump back to life along with alot of other eletrics.

But there is still no fuel getting  to the engine (yes there is plenty in the tank).

Looking futher into this I remebered that there was also filter at the back next to the pump. Is this normaly the case that theres 2 fuel filters if so, why? Ive also yet to try clearing the fuel lines so this could be the issue.


James

How long have you had the car? Has it always run OK before this. Sounds very like rotten fuel filler, muck/rust/water in tank syndome. Shouldn't have a second filter but could have been put there to stop debris getting to pump.

Ive had the car for about 13 months and ive slowly been restoring it one of the things i've also changed the filler neck since it was rotten. Ive also had a look in tank via the fuel sender. There is quite a bit of crud in there im going to try and clear it this weekend.

In regards to the fuel filter at the back i've had a look on vagcat and it shows a filter on the diagram.  I just cant understand why theres one there and on the metering head. I havent seen anyware thats selling after market for it replacements either nor  is there any info in my haynes.

As far as I'm aware there is no filter by the fuel pump for injection models. There may be a bit of mesh at the intake for the pump that could be blocked if there is crud in the tank though.

Later cabbys have a strainer filter next to the tank above the fuel pump - There is a pic on here somewhere

It's cream/white

So in fact these have three - a strainer in the tank - the strainer/folter nect to the tank and the main filter on the metering head - VW paranoid or what by the late 80's  8O

Have a look on Prowler's website here and scroll down a bit.

dannyboyblue said

Have a look on Prowler's website here and scroll down a bit.

I assume the pics here are of an injection model?

Having fuel contanination problems with my 1.8 Carb.

Thanks for all the info guys, I?ve started pulling the fuel system out to try and find the cause of the problem.

So far I?ve checked:
The fuel line to the front seems clear
The fuel filters at the metering heads new so that?s ok
I?ve looked at the strainer in tank (thanks for the link) that?s clear.
The fuel pump seems ok its only a year old and cars only done 50miles max since then so I can?t imagine that gone again.


I?ve now got to try and get this filter out which is above the pump. Everything seems very rusty around this area of car.  I think it?s quite likely that this filter hasn't been changed for a while looking at the state of it. I'll post some pictures when it?s all out. Is this likely to cause the problem?


It?s strange because it made no signs that it might be fuel starved it just stopped.

James,

Can you be clear on what engine you have and what fuel system?

DX engine??  Carb, Injection??

How have you verified you have no fuel at the engine?

Never assume a new item work OK until you have tested it is OK!

Cheers

Rich

Sure sorry I should have said its a DX engine 1.8 injection lump.

I've done prowlers injector test this showed no fuel coming out of the  injectors. Ive done this befor a few times successfully.

OK - we have a Gti Cabby.  Probably has a lift pump in the tank.  no fuel at the end (injectors)

Between the fuel and the injectors and back agian we have:

Tank
Lift pump strainer
Lift pump
Lift pump power
Tank block strainer (next to the lank - cream coloured thingy)
Fuel pump strainer (depends on the pump)
Fuel pump
Accumulator
Supply line
Filter
Metering head
Warm up regulator
return line

That's a lot to test!

Start at the beginning and work through - ask where you get stuck

My money is on the lift pump not running (what I mean is not pumping)

Did you run it empty??

Cheers

Rich

as said, how have you veryfied no fuel? if there is fuel getting to the metering head, it's very likely pressure. the injectors do not open unless they get 47psi of pressure. you want 76psi at the injectors. this can normaly be achieved by shimming the metering head. that's assuming fuel to the head has good pressure.

wooders said

how have you veryfied no fuel?

james75 said

I've done prowlers injector test

Thanks for all the advice everyone. I?ve been working though crazyquiffs list. I've reached testing the fuel pump.
As I mentioned earlier it only 13months old and has done next to no miles since installed.
I removed it from the car and connected it to straight to a 12v battery.
There was spark and crackle when I connected it up but the pump did not move at all.

Now that I?m aware of the existence of the lift pump and its role also the fact that it makes a pumping noise.

I now believe when I was doing injector test that I mistook the sounds of the lift pump for that of the fuel pump.

Is there any reason why my fuel pump could keep failing?

Hi James

Just read this post, as I have been sorting out the same problem,
mine just stopped, and I have just replaced the tank,filler neck
fuel lines etc.. filters etc..  mine turned out to be a tank full of muck
that blocked the pump up, even if theres a bit in there it wont take
much to stop it working, only way is to flush out or replace the tank.

Just out of interest, did you use any sort of sealant / gasket stuff
on the metal fuel pipe on the pump (the end where the wires are)
as mines Pi**ing out everywhere!  :roll: just when you think its
all sorted.

Good luck  :wink:

Marc

If there is debris in the tank that will jam in the pump. Happened to me when I restored my GTI, got 99.99% of the cr P out of the tank but still a few bits stopped the pump working. Removed pump blew out the bits and it worked ok again.

Eventually I fitted a big in-line filter between the tank outlet and the pump. Some pumps have a gauze/mesh in the pump inlet. (which then gets bunged up and casues poor running)

Basically its a bit of a german design bodge. There should be a filter infront of the pump and acculumator not after them  

I?m glad to inform you that I?ve successfully fixed my fuel supply problem.
The pump had become blocked. So I took the whole fuel system out and cleaned. In process managed to snap my brake lines. So i have a new set of metal and flexi break pipes. While doing this i found that the master brake cylinder was leaking a not supplying one drum. I also found a broken rear cylinder along with a snapped handbrake cable.

Thanks for all the help!