SLROC Forum

Hi, have a 1999 TD5 Disco which has an annoying misfire at about 2,500 revs. Had loom done but no better?
At 2000 revs and at 3000 its fine just a real pain at 2500,anybody any idea's.Thanks

diesels should not misfire unless there is no fuel in the cylinder, as it is firing at 2000 and 3000 revs there seems to be fuel there.

perhaps the new injector loom is a faulty one? (there is no guarantee that the crimp connections on the new loom are any better that the old one. sometimes it just best to solder the crimp joints)
afre the connections to the main loom ouside the rocker cover clean?
are the connections to the ecu clean?

the frequency of vibration at 2500rpm may be wobbling some loose wirework or sensor at its resonant frequency causing some intermittent voltage to the injetcors etc.

just one thought......

chhers for your prompt reply, local garage did the loom , maybe misfire is wrong word but best way I can describe it bit like kangaroo petrol !!! can accelerate through it and have plenty power just at 2500 feels like misfire!!!
Will check out your advice and thanks again

Take the plugs off the ECU and see if there is oil in the Red one.

What is usually described as the kangaroo effect is a sticky wastegate and the ECU cutting fuelling when it notices overboost. Depending on how sticky the wastegate is, I assume it can happen at various rpms from 2000. But then you would have reported loss of power going up in the revs (or trying to). As you're not reporting that, it must be something else.

Hi All
Have had injector loom replaced,garage cleaned plugs etc !! re wastegate sticky will get that checked ,vehicle goes great at 2000 revs 50 mph only between 2000 and about 3000 really struggles to run smoothly then once past 3000 or so it is all good again. Looks like need to get it on diagnostic !!!!
Thanks all

Yes. The diagnostic might not give you the answer but it could point the way. You could find someone with a nanocom in your area and you could go for a drive and record fuelling.

Hi All
Have had injector loom replaced,garage cleaned plugs etc !! re wastegate sticky will get that checked ,vehicle goes great at 2000 revs 50 mph only between 2000 and about 3000 really struggles to run smoothly then once past 3000 or so it is all good again. Looks like need to get it on diagnostic !!!!
Thanks all

I would double check your plugs, even although they have been cleaned you do still get a little residue coming out.

The other think to is check your turbo hoses for delamination (need to take them off) a restriction will also cause the problem you describe. (had this on two different TD5's now)

I have a nanocom and happy to plug it in for you but dont think it will show what the problem is.

Yep check all the hoses thoroughly. Also check the ECU isn't full of oil (remove and stand it on end), same for the fuse box. Have known the contamination to get so bad that these parts flood and the oil shorts connections! As said, check the wastegate actuation.

A plug in to Testbook will show whats working as it should and what isn't! Can put you in touch with a ood uy if you need a contact

Hi All
First just to say thanks to everyone for all the help and suggestions first class crowd. Rangerovering ! yes would apprciate any contact you can give me.
Again many many thanks yu guys

PM Sent