2.5td loss of power

My 90 2.5 TD looses power at 50mph and above. At the same time the engine over revs when weight is taken off/clutch in. It has been suggested that air is entering the fuel line. I have checked this and cannot see any obvious leaks. Have also changed inlet/ exhaust gasket.
Any ideas out there please???

alan3773 said:

My 90 2.5 TD looses power at 50mph and above. At the same time the engine over revs when weight is taken off/clutch in. It has been suggested that air is entering the fuel line. I have checked this and cannot see any obvious leaks. Have also changed inlet/ exhaust gasket.
Any ideas out there please???

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Once again because it is a diesel engine, it MUST be a fuel starvation problem if there isn't any simple mechaical fault.

Is it getting full throttle at the pump lever?

Maybe the fuel filter is needing changed, or a fuel pipe is kinked, fuel tank pick-up strainer blocked, lift pump failing ...... all those routine simple DIY things. Take the fuel delivery pipe off the injection pump and aim it into a bottle.

Try the priming lever on the pump - the fuel should skoosh out as a good squirt. Taking great care, whirl it over on the starter ..and it mshould pump fuel like crazy.

If not, you may have your answer, and a solution for about £20.

CharlesY

Thanks. Have changed pump, fuel filter already.

just a quicky, dont mind if i step in?

how long should a fuel lift pump last? records show mine changed around 2 years ago. but ive got some probs which may be attributed to the pump. should i replace it?

G

did you manage to find an answer to this as I have a similar problem? I have a 2.5td defender 110 '86, I have changed the fuel pump, fuel filter and injection pump. I have checked all the feeds but still in 4th and 5th at max revs the power goes and the engine dies, any help would be appreciated?

Happened to my 2.5TD a couple of months ago but it had been happenning very gradually for the previous 6 months but I got used to it being slower. At about 50 mph in top gear, put your foot on the pedal and it would start to cut out but revived on lifting your foot off. The remedy was a rubber diaphragm in the injector pump which costs about £30 for the repair kit. Does your fuel tank get pressurised after a run? Try taking the fuel cap off and seeing if it blows out at you after a run.

Good luck with it

borntobemild said:

Happened to my 2.5TD a couple of months ago but it had been happenning very gradually for the previous 6 months but I got used to it being slower. At about 50 mph in top gear, put your foot on the pedal and it would start to cut out but revived on lifting your foot off. The remedy was a rubber diaphragm in the injector pump which costs about £30 for the repair kit. Does your fuel tank get pressurised after a run? Try taking the fuel cap off and seeing if it blows out at you after a run.

Good luck with it

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Hi again, brilliant this sounds exactly like mine, yes the tank becomes pressurised and blows out Diesel, is the diaphragm easy to fit or should it be done in a garage? I ask because I know the injection pump can be tricky to play with and I have limited specialist tools?, thanks again

If the tank is getting pressurized then the breather is blocked, and could be the answer to your problems.

GRUNT said:

If the tank is getting pressurized then the breather is blocked, and could be the answer to your problems.

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hi, could you clarify what you mean by the breather please, I have checked the return pipe from the filter to the fuel tank, fuel tank to lift pump, lift pump to fuel filter, fuel filter to the injection pump, and replaced most of the pipes to new ones is there another pipe I need to check that I have missed?

If I left the fuel cap off would this prove if its a blocked pipe or a diaphram problem? any other suggestions would be welcome

First thing I checked was the breather pipe but that only runs from the top of the tank to the neck of the filler pipe letting out the air as the fuel goes in. The tank becomes pressurised by fuel which should be going to the cylinders under pressure leaks passed this little diaphragm in the pump and back to the tank.

I didn't tackle it myself but my garage took an hour without removing the pump itself. They told me that people often replace the whole pump, for between 450 and 1000 pounds when the repair kit only costs about £30.

First thing I checked was the breather pipe but that only runs from the top of the tank to the neck of the filler pipe letting out the air as the fuel goes in.

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Its main job is to let air in as the fuel is used so as not to form a vaccuum in the tank making it harder for the pump to suck fuel out of it.

hi all, thanks for your help. Had the injection pump diaphragm replaced, did the job the engine is back to normal, apparently they fail quite often and usually blow a hole in the older fuel tanks due to the extra pressure build up.

i wish i had heard this when i had my 2.5td i had the same problems and sold it, not being able to figure out wot was going wrong. damn

anyone got a part number for the kit?