Injectors......CLOSED

[alewing]

Hoping someone can help.

1990 T25 Transporter.

I have a 1700 normally aspirated diesel, which has just started running differently. I recently started to use injector/fuel system cleaner! I have not changed the fuel filter for a while.

It starts fine (some small amount of white smoke on initial start), but tick over has become a little noisier and uneven. As i gradually accelerate (1st or reverse), it becomes very lumpy and juddery. As the revs increase the problem dissapears and driving above about 1200rpm is as normal. No smoke or extra fuel consumption noticed. The vehicle drives fine otherwise, sits happily at any speed as long as the revs are above about 1200.

I feel I may have one or two dribbly injectors, but then they function correctly when the revs are increased.

I have a set of injectors from a 1600 JX turbo and a set from a 1900 AAZ turbo – does anyone know if these are suitable/compatible, so that I can swap them over whilst I have the 1700 injectors looked at?

Or any other thoughts and advice would be greatly appreciated.

Many thanks, Ashley

[ewenmaclean]

Hello,

there are various things to check I'd say:

1) Air in lines
2) Water in fuel
3) Timing
4) Injector seal leak
5) Compression
6) Decent air and fuel supply
... (many more)



I doubt it's 6 if it's ok at higher revs. You can check for an injector seal leak by spraying a bit of washing up liquid+water around the seal while it's running.... Might be worth just cracking off each nut at the injectors in turn with a rag below until the fuel runs out without bubbles - diesels can suffer from air locks in the fuel system and these can manifest themselves in annoyingly unpredictable ways.

I'd be surprised if using injector cleaner has hurt the injectors, but it might be worth draining the water from your fuel filter just as a precaution - there should be a screw fitting below it which will drain it off.

Good luck finding the problem

Ewen

[alewing]

Thanks Ewan,

I've already done the 'cracking off' - no difference
When you talk about injector seal, do you mean between the injector and the head?
Will drain the filter tonight.

I have managed to get hold of a set of injectors so will also swap them over and try this evening.

For Information, Normally Aspirated and Turbo Injectors are not compatible or interchangeable (they are rated differently regarding the pressure they inject at. 130Bar ~ 155Bar respectively)

Many thanks,

Ashley

[ewenmaclean]

Hi Ashley,

sorry - forgot to answer the bit about the td injectors! For seals I mean the copper washers between the injectors and head yes - you're not supposed to reuse them, but if you can get rid of ridges and make them flat then it's ok as long as the mating surfaces are very clean. I'd just clean up that area of the head and get new ones - order them in from vw - sorry not sure of the part number but vw parts will tell you.

Ewen

[alewing]

no copper washers present. heatshields instead. discovered cracks around 2 of the injector housings!! now required to repair and test this head or find alternative useable head.

[ewenmaclean]

that's bad luck - hope you manage to fix it. Sorry about getting the washers/heatshields thing wrong - on mine it's copper washers -forgot it's different on older n/a engines...