2.5 TD no top end power????

Hi everyone.

I am new to this and bought my first land rover about a month ago.
I have a 1988 E reg Defender 90 2.5TD which has 109k on the clock.
I have started to notice an issue which I will struggle to solve with my current limited knowledge and would be very grateful to anyone who has experience or advice to offer about this. So here goes!!

When I first got my Land Rover it pulled well in all gears and would happily sit at 60mph whilst still revving quite low. Recently the top end power seems intermittent to say the least. For example, yesterday I drove to Dalby Forest, a round trip of around 150 miles. On the way home it wouldn't break 40mph on level ground. When I got home the engine idle was very erratic and sounded like it was misfiring. If I put my foot lightly on the throttle it was fine again until I released it. I went out around half an hour later and it started and ticked over nicely.

Today I drove around 10 miles on a flat stretch of dual carriageway. It would do up to 50mph in 4th gear but when I went into 5th it remained at 50mph. It made no difference whether my foot was flat to the floor or lightly pressed on the pedal. I stopped and then drove another couple of miles and it was running perfectly again. Stopped again and it was "limited" to 50 again.

Any ideas where I should start to find this problem?? When I bought the vehicle I was told that all the filters were recent as were the glow plugs and the turbo actuator.

If it had never run well I probably wouldn't have noticed and accepted that 50 mph was it's limit however as it intermittently has these bursts of energy I'd like to find out what's wrong with it.

Thanks in advance!!

M8CPK said:

Any ideas where I should start to find this problem?? When I bought the vehicle I was told that all the filters were recent as were the glow plugs and the turbo solenoid.

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someone enlighten me as to what one of these is ?

Doh!! Don't know where that came from!! Meant actuator!

hmmmmmmmmm cracked piston?

Sean said:

someone enlighten me as to what one of these is ?

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fook it beat me to it

seeing as it's a TD it could be a number of things, including split rings, split pistons or just a lazy lift pump - would be a good idea to do the filters again just to be sure

Hi there,

Got the same age and engine as you and had the same problem a couple of years ago. The problem was traced to the rubber diaphragm in the fuel pump. Don't be persuaded to fit a new fuel pump at huge cost when a repair kit for the diaphragm is available and can be fitted for £100-120. Depending on how hot the fuel pump is and whether there is a littlle tear or a huge split will determine whether it works one minute and not the next.

Regards borntobemild.

the lift pump and injection pump are two different things - the lift pump is about £25 new and is very often the cause of such issues

and it's very easy to change

STC1190 Fuel lift pump - mechanical - 2.5D/2.5TD/200TDI

Just a thought, but might the engine have sucked in a bit of water. If you have a paper air filter then it might have gone soggy, disintegrated and got sucked into the turbo and jammed it.

Thanks for the replies. I've ordered a new lift pump and will change the fuel filter and check the air filter. Watch this space!!
I only hope it is something as simple and relatively inexpensive!

Air temperature can also drmatically effect the top speed that you'll gain with an N/A or a TD. Whenever I drive down the A1 to Ipswich, my N/A will either fly or crawl, depending on the air temperature. I went down on Friday and could barely reach 60, coming back last night I could maintain 70 most of the way. Rubber diaphragm is also one thing (as suggested) as is clearing the fuel lines of any gunk. If you fit a new filter, fill it with wynns diesel treatment and run the engine on that for a little while.

-Pos

my TD wunt go above 50, don't bother me though

well that's a lie, I can do 60 down a slight hill.

Got a new lift pump yesterday but unfortunately it was the wrong one. One I took off didn't look too old. Replaced fuel filter and found a brown jelly substance in fuel filter so looks like dirt in fuel tank. Added some diesel magic and seems to be running a lot better. Looks like it's been a bit neglected in the past. Hopefully solved the problem.

Mine didn't run well when I first got it. It could have been air bubbles in the fuel lines (the bolt in the top of the fuel filter has a pin prick sized hole in the bolt which purges the air, it get blocked easly), but I cant say for sure as I changed all the filters as well. I noticed a real difference when I did an oil change, once again not sure if its relevent.