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Model specific boards => Golf mk2 => Topic started by: bmouthboyo on 24 July 2009, 13:06
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Hello again all,
After some fault finding I have put the problem of my DX engine not starting down to the 4 injectors are not giving any fuel. The cold start line is however.
The engine was working fine before I removed the head to have a stud removed, all refitted with timing correct (well same as before) and new gasket and bolts.
I have not tampered with anything else and fuel is obviously being pumped as the cold start has a lot of pressure as its ment to but the injectors have non. I have even removed the actual injector incase blocked and still no fuel so must be some thing to do with how its dispensed at teh air filter housing.
Any ideas?
Thanks
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Is the pump running.
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Yes the pump is running fine.
Few other points that might be of use:
Only about half a litre of oil in the engine as i wanted to ensure it ran before doing the usual service incase i have to take apart again.
No coolant in system.
Engine is in a T25 Camper and has been sat still unran for 5 years. When I bought it a few months back it was running but had cracked manifold, hence all this agro removing head etc.
Other than the head I havnt fidled with anything. I read somewere if the air filter housing isnt tight it can prevent it pumping?
Only saving grace is the cold start line is workign correctly
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With the ign on and one injector sat in a glass jar, leave the other 3 in the head for now, if you lift the metering flap it should deliver fuel if not then metering head has problem or injectors
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As above. I would say its ur metering head. Dont think they like to be stood for to long and tend to seize up or get full of old sludgy petrol
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With the ign on and one injector sat in a glass jar, leave the other 3 in the head for now, if you lift the metering flap it should deliver fuel if not then metering head has problem or injectors
you'll need to bridge the fuel pump relay so the pump runs continuous, ignition on wont be enough. Also a bad idea to do this test with the other injectors in the head still as it'll flood the engine
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With the ign on and one injector sat in a glass jar, leave the other 3 in the head for now, if you lift the metering flap it should deliver fuel if not then metering head has problem or injectors
you'll need to bridge the fuel pump relay so the pump runs continuous, ignition on wont be enough. Also a bad idea to do this test with the other injectors in the head still as it'll flood the engine
Point taken but not many people have 4 glass tubes lying around.
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or just chuck all 4 into a big container, atm we're just testing they work and for good spray pattern, rather than going as far as checking delivery volumes :)
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but yeah you're right, ideally we want 4 equal sized tubes so we can check the delivery volume at the same time, but just konwing if they're buggered or not is a start :grin:
I had exactly this on my 16v, turned out to be a clogged fuel filter, so worth a go if not replaced recent. fuel was getting to the metering head but not enough pressure could build up to open the injectors
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Ah great thanks for the advice.
The pump is a "bespoke" one lol, basically to turn it on i have to turn the side lights on, dont ask me why, soon as its running im getting an auto spark to wire it properly. So basically I can easily get it to run all the time.
I have removed 2 of the injectors and there not giving fuel from trying to start it normally.
Regarding the fuel filter causeing lack of presure to open the injectors, i have even removed the fuel line from the housing at the air filter end and it doesnt come out.
How do I manually lift the metering flap?
Thanks
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To manually lift the metering flap, use something to grip the center nut on he plate but be carefull
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I recently brought a F reg gti 16v mk2 of this bloke, it has been sat on his drive for @ 10 years due to his health problems. Anyway one of the problems i had with it i sorted last nite. she was constantly flooding and missfiring. The air meter flap was very hard to pull up and then become loose. , All i did was remove the distributer from the air box, The needle in the center under the fuel disributer was very stiff in its seals, i carefully pulled the needle out with a pair of pliers with its jaws wrapped with rag so i didnt mark it, cleaned it with petrol. (it should be spring loaded and push in and out quite free. boy is she running sweet now! it seems like you have a similar problem. good luck :grin:
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OK bit of an update:
I went and manually lifted the pressure plate and a tiny amount of fuel seemed to trickle through and injector i had removed.
I think the fuel filter is old and when I undid it to remove it a lot of yelloish fuel came out, albeit the reverse of the filter so i guess expected.
What I dont understand is there is lots of pressure and fuel coming from the cold start line, but nothing from the injectors. Could the piston thing on the fuel control valve be blocked? Any way of cleanign them or is it a new air flow distributor job?
If so anyone know where I can get one?
Thanks
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You've disturbed an elderly metering head from it's nest. It's going to be upset.
It will probably now be well out on where it should be, so chance is you'll need to work on re-calibrating it, which is going to be a complete and utter ball-ache.
Quite seriously, this is one of the biggest things about K-jet that put me off ever bothering with it again. I've been in so many situations where the metering head's been out of the vehicle, not much has happened, it's gone back in and been shot away. I suspect it needs adjusting to sort it so something actually happens when the flap is lifted. At the moment it's probably way off the bottom of the scale. You'll need an absurdly long allen key to adjust it up in to range.
If it were me I'd be off looking for a dead car with a good Digifant injection system on it - it'll take away a lot of these problems. Finding another (good) metering head will be a bloody nightmare, too. Have a look at replacement prices, just make sure the jaw-catching tray is in place before you start looking.
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the cold start line doesnt need as much pressure as the main injectors as it is electrical, plus its on a different part of the metering head as the main injectors. the 5th injector just gets a steady supply of fuel whereas the main injectors have a varying supply based on the engine load.
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You've disturbed an elderly metering head from it's nest. It's going to be upset.
It will probably now be well out on where it should be, so chance is you'll need to work on re-calibrating it, which is going to be a complete and utter ball-ache.
Quite seriously, this is one of the biggest things about K-jet that put me off ever bothering with it again. I've been in so many situations where the metering head's been out of the vehicle, not much has happened, it's gone back in and been shot away. I suspect it needs adjusting to sort it so something actually happens when the flap is lifted. At the moment it's probably way off the bottom of the scale. You'll need an absurdly long allen key to adjust it up in to range.
If it were me I'd be off looking for a dead car with a good Digifant injection system on it - it'll take away a lot of these problems. Finding another (good) metering head will be a bloody nightmare, too. Have a look at replacement prices, just make sure the jaw-catching tray is in place before you start looking.
ouch lol
What is puzzling me is it wasnt removed from the head, just left as it was whilst I sorted the head and manifold out (thanks btw), im looking for a replacment and in meen time replacing the filter and having a little tinker. Fingers Crossed
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OK bit of an update.
Today i replaced the fuel filter and put the metering head back on after trying to clean it out as best i could, the piston moves freely and i blew down the main hole and seemed to push some crud out of the holes that lead to the injection lines.
Poped it all back together, the injectors seem to be working (although not perfectly as sometimes one doesnt seem to want to squirt. I swapped the working and non working injectors around and still same lines not working. It seems that some times there just isnt the pressure to work the injectors on a certain line.
I have a feeling that the metering head is still at fault and possibly gunked up a bit still. I have 2 replacments on the way so will try them and see.
On a side note, i tried to start the car when all 4 injectors seemed to be working, but when its tcranking there does not seem to be enough suction on the air intake to lift the plate to deliver fuel, I removed an injector and whilst cranking nothing came out, however when i manually lifted the metering flap fuel comes out. Could this be a simple leak in the piping somewhere preventing there from being enough suction to lift the plate during the crank? The plate moves up freely but i wouldnt describe it as "no resistance at all" as when the pumps working it is a tad harder to lift.
Any comments appreciatd, ill keep you updated.
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if 1 injector isnt spraying and the problem remains when swapping an injector over id say your metering head has crap in it, and now its basically scrap. 1st thing on the list is a new fuel filter, and before you fit the new metering head put the main feed pipe into a container and prime the pump a couple of times to ensure there is no crud in the system. you'll want to blow out all the bay fuel lines to make sure theres nothing lurking there, and ideally replace the wur as this could have crap inside too. I've seen guides on opening them up to clean out the insides but not sure that would end well.
2nd hand mheads are a risk too, have to hope that whoever stripped it off did it properly and stored it carefully so as not to let anything get inside