Air in injectors

[littleredvan]

Having a little trouble with my diesel injection and was wondering if someone more knowledgeable has any advice. The van in question is a 2.5Di 1997 smiley (viewtopic.php?f=27&t=62648). Sorry, I don't know the PS for the engine, but it doesn't have the banana manifold. Injectors are equivalent to 33704 and it's a bosch injection pump, number ending 141 414.

The van runs very well for the most part (no smoke, plenty of power ) but suffers from an intermittent three-cylinder run that can almost always be resolved by bleeding the injector at the back of the engine (next to the bulkhead) with a 17mm spanner . This is the injector that currently carries the leak off back to a t-piece on one of the fuel filter lines.

I changed the lift pump to try and resolve this (which incidentally had a small amount of engine oil in the diesel pipes) but this hasn't really helped. The van last had a new fuel filter 2 months ago and I've checked for water collecting in the filter.

I've got some replacement leak-off piping to do the leak-off mod - I'm assuming that I should replace the length from the filter pipes to the back injector with a length to the front injector instead and swap the blanking plates? I have a metre which seems like it should reach - does it matter how the pipe is routed?

I'm considering swapping the injectors, but at about 45 each (http://www.uniteddiesel.co.uk) a full reconditioned set would end up being quite expensive. Would air be likely to collect above a faulty injector (as it is almost invariably the back injector that needs bleeding) or is this just where air normally collects if air gets in to the system? I'm tempted to just swap the one injector out at the same time I do the leak-off mod. If I could find replacement PTFE washers I might try replacing all the injector sealing washers but I can't find any that fit at the moment.

Any advice would be greatly appreciated.

[Steve B]

I think the leak off mod will solve this

[alanwh]

Your getting air in somewhere mate try lift pump and filter unions. make sure filter is seated correctly.

[roseman]

Try changing the 4 O rings on the pipes into the filter-head. They cost 60p total.

[bishbasbosh]

its an interesting one this i also have this problem but not all the time. seems to be quite common with older vans.. dont know if mine is cured yet changed fuel filter and air filter today for a start... ive seen lots of people say its lift pump related ?

[Eggski]

Yeah mine was the lift pump, different van now its sorted. Good luck.

[bishbasbosh]

thanks i will prob change it. rules one thing out and its not really that costly so gotta be worth a go...

[littleredvan]

thanks i will prob change it. rules one thing out and its not really that costly so gotta be worth a go...

Less than £20 for a new one and swapping mine was easy (although unfortunately in this case didn't resolve it). Two 13mm bolts (four in total if you remove the heatshield for better access) are all that you need to undo.

Try changing the 4 O rings on the pipes into the filter-head. They cost 60p total.

Hadn't considered this at all. I'll have to have a look through my plumbing toolkit and see if I can find anything suitable. Anyone happen to know what size these are from memory if I don't happen to have anything that looks suitable - I'd feel a little silly going to them factors and not knowing the size Alternative is of course a scrappy filter head...