Series 3 Slow old diesel

Hi all and merry Christmas. I have recently bought a series 3 swb with the 2.25 l diesel engine. The top speed seems to be about 25mph in third gear and it struggles in fourth gear. All my other series have been petrol but I'm almost sure that this can't be right even for a diesel. And thoughts please? Dave.

Have you changed the diesel filter?

It has had a full service but I will try that just in case mate. Ta

Also with the engine OFF check you can get full throttle.

Same as mine, not quick or powerful , mine in overdrive and 750 x r16 tyres and ok at 50mph , I’ll check tomorrow what top speed is on flat in 3rd , Valve clearances checked? All the brakes not binding inc transmission brake, air filter should be clear , does it start easy enough, as hi cap says with pedal down is the throttle arm at max, injectors working ok , you can check spray pattern with them disconnected , pump timing? Does it accerlate to 25mph in 3rd ok , in 4th or even 3rd can die on modest hills!

No that very wrong.
Does it smoke or knock.
How well does it start when cold?
They are not the best but thats way down on power.

Nick.

Should handle steady 50mph on flat with wind in favour. Hills or strong head wins have a big impact, 3rd at 30 can usually handle anything. As suggested sounds like u have a minor issue, a good tuning makes a massive difference!

Air in the fuel system? Try bleeding it. 25 mph is woeful. I once bought a series of a lad who said it wouldn't go over 30 mph. turns out it was in low ratio...
On another subject try the air inlet pipe from the air cleaner to the inlet manifold, I had a series once where the internal integrity of the pipe had started to collapse, it was ok at idle but as soon as there was any suction on acceleration then the internals collapsed strangling the air flow.

Thanks chaps I'll have a good route round as suggested over the next few days now that I know it is definitely 'underperforming'. Dave.

charlie701 said:

Thanks chaps I'll have a good route round as suggested over the next few days now that I know it is definitely 'underperforming'. Dave.

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It takes a while to get there but on 7.50's I can hold 50mph in 4th happily, and 55-60 mph in overdrive (on the flat, show it a hill and it slows down). In overdrive with a bit of down hill it will get to 70, but that is a little scary.

You have said it has had a full service but who carried it out? Unless it was yourself or someone you trust I would go back and check everything. the above suggestion are a good place to start. If it was a brake binding ti would very quickly get very hot, so I would suggest it is an engine problem. Although I expect you could tell the difference if you have had land rovers before it may be worth checking it is not stuck in low range due to a seized linkage even if the lever is in high. Other than that, I would bleed the fuel system, and check no air is getting in or fuel getting out, and then check the timing.

Put some injector cleaner through it as well, may help. Is the exhaust clear? The diesels can gum up the silencer. I agree re full throttle check, when mine developed a top speed of 40 the throttle link had slipped round on the shaft. Check the shut off is fully in the run position.

rob1miles said:

The diesels can gum up the silencer.

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I cannot see this being the problem, Land Rover installed a very clever fix for this in the manufacturing process whereby the silencer would rust away allowing for more free air movement though the exhaust as the vehicle aged and the silencer material became blocked with soot

Based on the chassis drain design?

Are you getting max revs in neutral it should be set for 4200 rpm , this is 48mph in 3rd I got 45 in my road test earlier today, it can be altered with the control screws on pump as in manual