lack of fuel to injectors...

Hi all,

following on from my last post where I replaced the metering head I have since realise that all is not as it should be still. It s an '86 mk1 cabby K-jet

I had noticed hesitation/misfire when floored, but given two or three seconds it would begin to rev, and go like a rocket. MOT man pointed out that the CO2 was way too high, and having adjusted the mixture the car will not run. It was screwed in around 8 turns, but I have been told it should be more like 2. It will not run at all until it is 5 turns in, but needs 7 or 8 to be smooth.

Fuel pump has been removed, and small filter in the inlet to pump cleaned. I also replaced the rubber pipe above pickup pipe in tank as I suspected it was split.

There now seems to be more pressure on the inlet side of the metering head (nut cracked, and fuel squirted out under presure having had the key turned for a few seconds).

I have not had the injectors out but I have had a fuel line off of one and with the mixture adjusted to what I believe is correct there is nothing but a drip when cranking the starter. Lift the intake flap and it squirts out.

Fuel filter next to metering head was replaced with the metering head.

I have two particular questions, but any other advise appreciated.

1. Can I clean my 2nd hand replacement metering head internally by soaking it in something ( i was thinking along the lines of brake cleaner, thinners, even lime scale remover) with out damaging the rubber seals? The plunger is free moving already, which was my problem in the past when it did not run at all.

2. Fuel path is …. tank….pickup pump….Unknown….presure pump… acumulator… fuel filter….metering head. What is my unknown? it sits up above the presure pump above the rear axle. Is this another filter? or another accumulator?

thanks in advance for any advice.

cheers
Ian :?

just found another post in the archives, regarding the function of the warm up regulator.

We had put a test light on the electrical feel for this but had nothing. I assume there should be a current for a period of time when cold? Can someone enlighten me as to how this circuit operates and where the bits and pieces are located.

I have had all the fuses out and checked, but would be useful to know which it should be so I can double check the obvious.

Is there a relay to control the time it is switched on, or is it a thermal switch? :?

This site may help explain

Domain parking page

ive got the same hesitation/misfire problem, and it struggles to start

ive read thro the link from chudd

but am still not sure,

some one here knows ill bet ya

mate chk this thread it could help
http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=11723&postdays=0&postorder=asc&start=0

the warm up reg should be permanant live when running you have a electrical problem somewhere  :dontknow:
check the injector seal are not drawing in air by spraying wd40 on to them with it running :wink:

Do prowler's injector test and report back:

Also read this:

http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=2948

OK, having read a bit more, and tinkered some more I have confirmed that the following are working fine…

Warm up regulator (and electrics)
Cold start injector
thermo time switch
fuel pump

Fuel filter is new. Metering head has been replaced for a known good one.
Fuel pump was replaced by previous owner about 500 miles ago.

I have had one of the injectors out and I can only get something out of it if I physically lift the air flap all the way up manually or have the CO2 adjuster screwed in around 13 turns (same thing basically). When is did do something I had a nice clean cone of fuel.

I am convinced its a fuel pressure issue. Although I have pressure there, I don't think its enough to fire all 4 injectors, only the cold start injector.

Going back to one of my original questions what is the unknown item in my fuel line? tank - lift pump - ?????? - pump - accumulator -  fuel filter.
Is it a filter? pressure regulator? it sits almost above the rear axle, above the lip of the fuel tank, about 6 inches from the pump.

I have had the lift pump out and the filter was clean, had the pump of and there was some dirt in the input filter…. the only thing between the two is this unknown item which I think could be clogged/blocked and restricting the feed to my pump.

ta
Ian

I think your on about the accumulator line should run lift pump,main pump , accumulator , filter - metering head etc

You are talking about the light brown/cream plastic thingy (only found on cabriolets) - ETKA lists this as a "fuel filter with expansion tank" part number 533 201 511 A

geezer, definitely something between lift pump and pressure pump. accumulator comes after pressure pump

crazyquiff, sounds more like it, not sure about expansion tank though. it about 6inches long, 2 inches round (although more square than round) dont suppose you got a piccy/diagram?

cheers

Ian

Ian,

That's it - I have one on my 91 cab also.

As suspected, it was this filter that doesn't exist on earlier models. Apparently a design addition around '84 (so only applicable to Cabby's). Sits in the location as described, has 4 pipes go to it, feed and return to the tank, return from the metering head, and the feed to the pressure pump.

Initially took the lift pump, tank, and unknown filter out of the equation. used a clean fuel can full of fresh unleaded, primed the pump and then used gravity to feed it and we got fuel from the injector.

Reinserted the injector (needs new seal still though), adjusted the CO2 to about 3 & 1/2 turns, loosened the timing bolt, had my mate turn it over and she ran, all be it very rough. fiddle with the timing, revved her a few time and ALL SORTED!!!

She revs beautifully from idle, to flat out where before it coughed and spluttered and eventually made her way to full throttle. Promptly ran out of fuel in the can as I was still using the return to the main tank though.

So need new injector seals, new barsteward filter/strainer and we're away!

I've got some photo's of the culprit, if someone wouldn't mind posting them for me (i haven't figured out how to do it yet). Perhaps the unknown cause of a few other problem on this forum, as despite searching, I haven't found any mention of it elsewhere!


YIPPEEEE!          

could that be why ive low fuel tank pressure???

and do we have a proper name for this part and maybe part no?

part number on it is 533 201511 A.

However I think barsteward filter is fine for general use!!!

Not sure on the fuel tank pressure. The filter is laid out with pressure pump feed and fuel tank return on the clean side of filter and on the "dirty" side is the fuel tank feed, and metering head return.

piccies will show you how bad mine was!! 20 years of crud!!

You can mail me the pics and I'll post them

found a good un
http://dana.ucc.nau.edu/~kaw5/fuel.htm

ive posted it up elsewhere but hey what the heck

how did you get to that bit , i know where you mean, looks tricky, any tips, please dont say ive got to drop the axle

crazyquiff, piccies are on their way. thanks, Ian