Can anywone answer fuel related questions?

[Golfo]

1989 Golf Gti 8v Digifant

Car has intermitent fueling problem.  Started 2 months ago, then ran fine for 600 miles now started again.

Both fuel pumps priming ok, starts fine, & idles fine, new fuel filter fitted, however..several problems.

Driving at constant speed and suddenly car acts as though it has run out of petrol.  Car continues to go but barely, with no power.  Press accelerator down futher and car goes Brrr and bogs..lift accelerator and car dies.  Turn key and car starts again.

Another problem has also developed in that car starts, runs for 2 seconds and cuts out.  Restarts fine but same thing happens several times before car runs normal.

I am convinvced it is fuel starvation but need to know following:-

Fuel Pump - This primes OK every time but can this fail intermitently or once it fails, would it fail outright and never work again?

Fuel Pressure Regulator - Is it possible for this to fail?  Could it sticking and witholding the fuel from reaching the injectors?

Relay - If this has gone southpark then would the pumps even prime in the first place?

Dirt - Could a blockage in the feed or return pipe be causing this?

Any help much appreciated.

Thanks

[vwsystems]

it wont be the fuel pressure reg as this only releases excess fuel from the rail......

the injectors are easy tested by a multimeter with ohms you can check all of the injectors at once and if one is out it will give a different ohm!

your haynes manual tells you how to do this and gives you all the ohm numbers

you said

Driving at constant speed and suddenly car acts as though it has run out of petrol.  Car continues to go but barely, with no power.  Press accelerator down futher and car goes Brrr and bogs..lift accelerator and car dies.  Turn key and car starts again.

my gti has done this a few times on duel carrageways but it hasnt done this for ages!!!.... and ive never found the cause but alls i can put it down it is the terminals on the fuel pump relay dont connects properly on my fuse box i need to sort it so that the little terminals in the fuse box grip and connect when i put the relay in.........

what i normal find that if i bent the terminals on the relay slightly that they connect with the fuse box...... and it runs normal

may be this may be the same on yours?

[rubjonny]

Check the fuel tank brether isn't blocked?  Straight after it cuts out take off the fuel cap and see if there is any pressure build up?

[roar]

I also suggest the above, i had exactly the same and that solved it. Take out the fuel gauge sender unit and clean the filter pipe.

[Golfo]

Thanks for the sugestions guys.

The problem, which seemed to be intermittent is becoming more frequent.

Today I was coming fown the motorway and could feel a continual stumbling and less acceleration than normal.

Also pulled up at a shop, came out and same problem..car starts, runs for 1 second then cuts out..does this several times before running but when it did go it ran really rough and lumpy.

I found the more i pressed the accelerator, the more lumpy it became.

I decided to turn the car off and when i started it again, it ran is if nothing was ever wrong..until i got 2 mins up the road!

I must give that breather a check, or check for pressure build up if it conks out first!

Thanks.

[Golfo]

Would anybody have any more suggestions?

The problem is happening all the time now  

I can more or less tell now as to when it's gonna start to happen.

First a general loss of power, then a stumbling, then worse loss of power etc until no power and really strugling to keep going.

The really bizare thing is that when you get to nearly walking pace it will might suddenly come back again as if nothing was wrong!  200 yrds up the road it will start all over again!

Another thing is that when i drive down a bumpy road, it seems to make thing 10 times worse!

I have checked over everything for a loose connection or loose earth but can't find anything.

I have taken the lift pump out of the tank and everything is really clean.  The mesh filter that covers the pump intake is nearly as clean as the day it was made!

I haven't taken the breather vavle from under the wheel arch off but when i take the petrol cap off, im not noticing any pressure release, either when he car conks out or any other time.

As it is now occuring all the time..if it was a blocked breather, then surely any time i take the cap off i should hear a hissing as i screw it off?

This leads me back to the Pressure Regulator?  Has anybody any thoughts on this being the problem

[mk1]

Check the blue engine coolant temp sensor for the ECU use a meter but as it intermittent fit a new one to eliminate it. You need to check the fuel pressure as it could be the injection pump starting to fail.
Steve.

[Golfo]

Cheers Steve.

Just been talking to some bloke in work who had the exact same problem as me on his Mk3 escort.

As it turned out it was his distributor that was causing the whole problem!!

[richandhazel]

This may help, digifant trouble shooting:-

http://www.richandhazel.servebeer.com/gti/mk2/fuel/main.htm#bentley

Loads of other info on my page too, have a look around.

[richandhazel]

Check the blue engine coolant temp sensor for the ECU use a meter but as it intermittent fit a new one to eliminate it. You need to check the fuel pressure as it could be the injection pump starting to fail.
Steve.

One of the suggestions in the 'digifant trouble shooting' is as Steve suggests^^^^ the blue coolant temp sensor. I have 2 tests available for that, an electrical and a function test:-

http://www.richandhazel.servebeer.com/gti/mk2/fuel/main.htm#blue

Let us know how you get on...........