Fuel injectors

[the edmundator]

Is changing/inspecting them as simple as pulling the out of their holes? That's the impression I get from the Book of Lies.

I'm pretty sure mine are leaking, as the GTI can be hard to start after sitting for a while once it's been run (i.e. 30 mins or more). If it's something I can check simply, then it's worth doing.

If I need to replace them, I believe it's just a matter of fitting new injectors and the rubber sealing ring, then pushing them back into place. Correct?

[Chaps]

Think so yeah.. looking at mine thats what I am intending to do anyway.
Worth getting new seals tho for the few quid they cost. Injectors arnt soo cheap tho - about 25quid a peice i think.

Are there any other side effects or is it just on start up your having probs?

[the edmundator]

Yes, the only problem appears to be difficult starting after being left for a while after being used. If I leave it overnight it'll start ok, but an hour or so and it struggles to get going. It's a little uneven idling when cold, but that might just be the WUR, which I think would be a separate problem.

[1lazza]

Hi Ed - sorry to hear you have a problem.

FYI it did not have problems restarting before being laid up (or immediately after!), so more likely to be dried up 'O' rings letting some air past. (Or do you suspect a dribbling injector leaking down into a cylinder?)

Have you checked the timing with a light on the flywheel, valve clearances and adjusted CO/idle speed after changing the cambelt as these can also be factors. If it is a problem with injectors, they pull out with a simple tool that is readily available. If you do this, make sure the plastic threaded insert into the head is undamaged and screwed home. Finally, injectors respond well to ultrasonic cleaning, which works out much cheaper than replacement. If it is the injectors, with the mileage so low, it can't be wear; worst case scenario, they're a little gummed up. If the problem remains, it sounds like a KJet diagnostic is required. Regards,

Laurence

[the edmundator]

(Or do you suspect a dribbling injector leaking down into a cylinder?)

That's what I was thinking, yes.

We were scuppered in our attempt to change the cambelt by the bolt securing the bottom fanbelt pulley. On later cars the pulley just pulls off over the bottom sprocket, but on this (and I presume therefore mkIs) you actually have to take the central bolt out as well as the four allen-headed bolts. We couldn't shift the centre bolt (presuming it's quite highly torqued) so I've sent it to the garage down the road.

[1lazza]

I'm pretty sure you should not undo the large nut in the middle! This holds the crankshaft sprocket on. I think the pulley should come off after removing the four peripheral bolts, then some prying and tapping to un-sieze it...

I do recollect adjusting the valve clearances during my stewardship of the car, so these are probably OK still. But clean the air filter, fine tune the timing with a gun and get the CO adjusted after changing the belt. This gives you a baseline to start looking at the warm starting isue. Best of luck!

Laurence

[Nate]

Ithe GTI can be hard to start after sitting for a while once it's been run (i.e. 30 mins or more).

If I leave it overnight it'll start ok

now i'm not overly familiar with k-jet (assuming that's what it is?) but this sounds like it isn't able to tell if the engine is cold or not. my money is on CTS or WUR

[the edmundator]

now i'm not overly familiar with k-jet (assuming that's what it is?) but this sounds like it isn't able to tell if the engine is cold or not. my money is on CTS or WUR

WUR I understand, but CTS is new to me... what is it unabbreviated?

[PeteGLi]

now i'm not overly familiar with k-jet (assuming that's what it is?) but this sounds like it isn't able to tell if the engine is cold or not. my money is on CTS or WUR

WUR I understand, but CTS is new to me... what is it unabbreviated?

I think he means CSV - Cold Start Valve

[Nate]

coolant temp sensor. i assume they have one so it knows when cold start stuff is needed?

[ChrisPears]

The injectors do just pull out, but they'll put up a fight. Mole grips levered off the rocker cover should do it. Putting them back in is a lot easier.

I had the same problem years ago. It would start on the button from cold, but left sitting for 30 minutes or so, it was a total dog to get started, turned out to be the injectors leaking effectively flooding the engine.

Could be the cold start system coming in when its not needed I guess. The 5th injector is electrically triggered isn't it? Disconnect it and see if it warm starts easier.