19j 2.5 td under fuelling?

Hi All, my 90 19J td keeps starving of fuel at about 50mph after 1/2 a mile or so and it tops out at 55mph? I've changed the lift pump and fuel filter and I can't see any leaks but I have no clue what to check next? It starts first time and does not black smoke at all (even under full load)!

Any ideas would be really welcome - one idea is the cav dps injection pump but don't know how to adjust it?

Thanks.

Hello,

If you're confident that the problem is fuel starvation (which sounds likely what with the lack of black smoke) you can try turning up the fuel on the injection pump. If you run your hand down the right hand side of the pump (side facing the engine) you should come across a bolt sticking out (it may be about 2cm in length). Slacken of the locknut and then wind the bolt in (it might be out - I can't remember!) two turns, tighten the lock nut and take it for a spin. Does it feel any better? Adjust it to your liking and then once it starts to black smoke when not under load, or on tickover - back it off half a turn or so. See how that goes, if it makes no difference then you may well have a split boost diaphragm. They do perish over time, and I'd put money on it being the original in your pump. Basically, as your turbo boosts, air is forced down a pipe to your injection pump which then presses down on the boost diaphragm to increase fuelling. If it's split, you'll be getting no extra fuel for the given amount of boost and it'll be sluggish all around. (see guide below):

http://forums.lr4x4.com/index.php?showtopic=33911

-Pos

Thanks Pos. I'm not getting any black smoke but I took the boost diaphram out and found it has split. Do you know where I can buy the replacement kit from? I've searched the net but cannot find anything.

Thanks.

Good stuff. The TD boost diaphragm is a part that only diesel specialists usually stock. The best thing that I can suggest is that you call your local diesel specialists (or try this company for example Diesel Bob Tuning - The ultimate diesel engine tuning as well as a diesel fuel injection service. Repairs and reconditioning of injectors and diesel pumps, suppliers of diesel fuel system parts and additives) and ask for the part. There are a couple of threads on here with links to companies that supply the part (I think it's as much as £20 or so!) so I'll try and dig a link up.

-Pos