Fuelling problem - no really!!

Just found your forum - halleluya!
I have an '83 Gti that stopped running sometime ago and which I should do something about.
It began hiccuping and in the end would start fine but soon died. The fuel pump (then new) would get louder as the motor died. It would run for perhaps a minute or so.
I did take it to an expert! Who charged me ?85 to tell me it was water and rust despite the new fuel tank and recent replaced filler neck. I drained the tank - no water or rust came out and checked the pump filter - ditto then lost interest.
I'm tempted to source a complete injection system from a recent runner. Unless someone can suggest where I should start looking. Once I've got it running I can then decide what to do with it.
Cheers
Barkstar

Reading the 1st bit I was just about to say cr P in the tank but seeing as you?ve had the tank replaced and drained it?. I?d still check with torch via the inspection hatch under the rear seat.

Did the fuel lines get cleaned out or may be they are still full of crud?

Was the filter on the meter head replaced?

Petrol does ?go off? if left for a long time so it might me worth putting some fresh in when you are sure the tank/lines/filters are clean

Cheers for that. I guess that, unless I go the wholesale replacement route I'll just have to work my way through each component. If only petrol wasn't so unpleasant, not to mention dangerous. Given how the motor slowly dies I reckoned it must be either pulling or pushing on some sort of blockage that the pumps pressure creates. I'll shove plenty of fresh fuel through the tank using the pump.
Really I'd like to spend as little as possible because I might put it on Ebay or even break it. But if I can sort out the fueling it might be love all over again. It was a hoot to drive.
Cheers
Barkstar  :dontknow:

It's alive!! She runs once more, which is a miracle as she's not even been turned over for well over a year. A mate suggested running a hose to a fuel can and see if that made any difference. It didn't, same thing, starts, runs for a few minutes then dies away with the pump getting noisier. Then if you leave it for 20mins it will start again but not run as long.
And I put a pipe on the tank outlet to catch any of the return fuel as it filled the tank back up and nothing came out. Might be nothing.
At least it's not the tank! And the clutch isn't seized either.
Barkstar

Have a look at Prowlers fuel injector test . Good way of getting a look at what is going on with the fuel system output, might gives some ideas. Also relatively safe as does not invole turning the engine over and creating HT sparks in close proximtity to petrol. What sort of condition are the hoses from the tank to accumulator/pump in? Just a thought, dodgy hoses could collapse under vacuum :dontknow:

Cheers

Cheers for that. When she fires up she runs sweetly enough- not missing and reving cleanly - then as the problem in the system seems to grow the pumps starts to strain against it and the motor begins to die. If you rev her she'll run a little longer. At no point does the motor missfire it just dies away. Leave her 20 mins and she fires again but doesn't run as long. Leave it a few hours and it again will run for five minutes. Whatever the problem is it takes sometime to disipate.
I hope to go through the whole thing in the next few weeks. I did replace all the metal fuel piping with high pressure rubber hose sometime back. I'm not sure about the problem being a vacuum, can't that only be created on the side of the pump that sucks? As the car runs exactly the same sucking on the tank or on a jerry can of fuel I'd think it must be on the push side of things That said though I get most of how K-Jetronic works I have no idea what the accumulator actually does.
I did wonder if it might be a problem with the return side, but would that eventually stop the engine?
Thanks for the input
Chris (barkstar)  :roll:

Interesting that you mention reving it it helps it keep running. Don't think you mentioned if this happens while you're driving it? Definetly try the fuel injector test as this allows you to monitor the flow of the fuel from min to max without having to rev the engine.

May be nothing, but sounds like the car is running ok when the cold start system should be running - i.e when started from cold. This would add the warm up regulator into the equation which does have some control over pressure duin cold start :dontknow: . Not sure about the fuel return, the pump should have a pressure relief valve to prevent to much presure building up if there is a blockage.

From what you say the pump/tank end of things should be fine so I would be looking at the bits in the engine bay now.

Cheers

The system pressure regulator allows fuel to return to the tank.  Although never tested I would expect fuel to always be returned to the tank at idle and reducing a fuel demand increases.  With no load on the engine fuel should always be returned whatever the revs.  I'd test this as the engine dies.

If you did not use fuel hose suitable for unleaded petrol it is likely that the inside layer of the pipe is breaking down.  This could be causing a restriction in the flow.  Might be worth letting it die, release the pressure in the fuel line and see if it starts easily again.

The only sure fire way to test is to get a fuel pressure guage on it and do the series of system pressure tests.  This will show where the blockage is.  In my view it is one of following:

Partially blocked supply line.
Defective WUR.
Defective pressure control valve.
Partially blocked return line.

Cheers

Rich

Thanks for the feedback and encourgement.
It's a while since I last drove it, but I recall if it started to died you could clutch in and rev up it would run a little further. As I said it missed a few times over a few days, then got worse and became undrivable.
Ric Wood's, who took a look at it said they'd found rust and water in the fuel distributor but none of the fasteners looked like they'd been touched. Though they must have done something as getting it the mile home was a long process.
It looks like its down to a fairly simple process of elimination. Though fixing it might prove hard on the wallet.
I'll put up a new post when I've solved it, it may be a week or two as I'm doing the Lombard Revival Rally next week - www.siteset.co.uk/endurance/ - but not in a VW, sorry.
Any further suggestions much appreciated
Thanks again
Barkstar