fuel pressure regulator

Hi Folks
Right ive just tried to start my car for the first time in 5 days, and yes you guess it non starter    after doing all the normal checks…..etc and giving the battery a full charge over night and putting a new set of plugs in still no go, since all of this i phoned a friend and he had me removing air filter box and pushing little flap inside….yea you guess it started    which i was then told its the

fuel pressure regulator

can someone confirm this for me, before i start my search  8O  
many thanks
mick

Mick,

My view is if the flap is lifted and the car starts this indicated two things:

1.  Cold start injector might not be firing causing a weak mix - the initial vacuum created is then not lifting the air flap which in turn meters fuel through the main injectors.

2.  A major vacuum leak so that the flap is not lifted when the engine is cranked.

I would do the Cold start injector and Thermo time switch tests to very their operation.

If this checks out Ok then the system pressure checks need to be done to diagnose the problem.

Keep us posted

Cheers

Rich

Hi crazyquiff

I would do the Cold start injector and Thermo time switch tests to very their operation.

could you be so kind to tell me what ive got to do to test thoses???

thanks again
mick

Haynes should give you details.  Basically test both bits by removing the CSI and putting in a jar - crank the engine and see of it squirts fuel for 8 secs or so.  if so all's well.

If it does not squirt, squirts for only a couple of secs or squirts all the time then you neet to diagnose the fault whoich could be:

No squirt:
No power
Defective TTS
Defective CSI

Short Squirt:
Defective TTS

Always Squirt:
Defective TTS
Defective CSI

To diagnose you need to check 12v supply to CSI, TTS continuity and resistance.

Cheers

Rich

To add to Rich's comments having recently been through all this myself, its also worth looking for Prowlers fuel injector spray pattern checks to make sure there is nothing amiss there.

Also before shelling out for a new reg, check the system pressures as Rich suggests and also make sure the fuel pump is delivering the quantity of fuel it should be.

If the fuel delivery test falls a bit short then your problem may be further back - filter on the fuel pump or gunk in the tank / partially blocked fuel lines.

Haynes has all the tests, but if you do decide to buy a replacement reg then the cheapest place I found was GSF as they required NO exchange unit and it was a genuine Bosch unit - about 150 quid all in I think about 2 months ago - pricey, but worth the peace of mind.

Good luck,

Chris

Hi
Right ive took out the injectors 1 at a time and cranked it over and there was no spray of petrol, now is this my problem the injectors are blocked and need a good clean or replacing or something else?, will the injectors still spray petrol while not correctly in place (aiming in a bottle) it seems odd that it started ok when i held open the little flap within the airbox with full throttle on
thanks again
mick

Doing what you have done does not prove anything.  To test the injectors do prowler's injection test described at www.vwgolfmk1.co.uk.

so you know the injectors need about 70-80 psi of pressure to give good spray pattern, i have tested some spare ones i have and they all seemed to be knackered apart from one.

so make sure you have good pressure if not try a new fuel filter.

Hi again
after realising i cannot just pull a injector out and crank it over to test sprays that way…..DoH    i then moved onto testing other things, mainly fuel delively….etc with no joy.
Since testing all thoses things and putting the injectors back, i just told next to just pull the HT leads off and place them on the sparks plugs as this would make the car try just that little bit harder to get a spark  :dontknow:  the car started, so i put the HT lead back on, but still not running right, iam getting the odd popping/backfire when i try giving it a bit of gas, but its popping/backfire from airbox not from exhaust, so now going to try new HT leads today…fingers crossed  :roll:
thanks
mick

Hi
Right ive just checked the Cold start injector and Thermo time switch and theres no power supply there  :dontknow:  not is there a fuse or a relay for thoses? or am i going to have to try rewire it?
thanks
mick

Just been reading your woes, checked the owners manual for mine (waiting for a haynes to turn up!) from the left fuse 5 is the fuel pump and 17 is call 'Carburetor', but I have no idea what this means, owners manual then say go to a VAG dealership  :?

On an earler post you say it's backfiring through thr air filter, I was under the impression this is due to timing, firing at the wrong time which could mean the leads are on in the wrong order.

sorry no exact diagnosis but food for thought.

Rob