Hi all

I have a 2001 4.8 V8 P38, currently having an issue with misfiring which has been there for a while.

My question is does anyone have a picture to show which leads go to which sockets on the coil packs. I have changed the coil packs and put the leads back to where they were, but now have just thought were they in the right place to start with as i still have the problem of a misfire.

I just thought i would go back to basics with trying to locate the misfire. Maybe right maybe wrong but got to try all avenues.

Any help appreciated.

P38BORDEAUX said:

Hi all

I have a 2001 4.8 V8 P38, currently having an issue with misfiring which has been there for a while.

My question is does anyone have a picture to show which leads go to which sockets on the coil packs. I have changed the coil packs and put the leads back to where they were, but now have just thought were they in the right place to start with as i still have the problem of a misfire.

I just thought i would go back to basics with trying to locate the misfire. Maybe right maybe wrong but got to try all avenues.

Any help appreciated.

Click to expand...

Search on here for RAVE and download it.Has all the info on there

Here land rover rave technical system

try this, works for a 4.6 don't know about 4.8 ?

Missfire's not always easy to diagnose, could be coils, HT leads, plugs for these try a spark tester set for High Level that will see if there is sufficient energy to fire the spark plugs. Plugs can also fail, pull each one off (engine off) run it and see if it makes a difference. Next I would do a compression test.
If all OK and you are getting good compression on all cylinders you should, at this stage, get some diagnostics done this might point to MAF sensor or other areas such as lambda sensors or Cat problems. If everything checks out try a vacuum test, on the top of the plenum you should be able to connect a vacuum guage, run the engine and if the guage is rock steady you may have (this test is not perfect) no mechanical (valves) problem if it is all over the place you may have a mechanical problem. Ok, if no luck so far) next on a Thor engine is to remove the top plenum and test that the injectors are receiving a signal from the Engine ECU (ECU,s not too expensive on eba..), you will need a noid light set for this. If all is OK you need to find out if each injector is fireing, you can do this in situ but will not tell you if the injector(s) are running properly, only way to do this is to have them checked over on a flow, leak and electrical test bench. So if the injectors are all ok what next? Well its out with the injectors and out with the lower manifold, off with the valley gasket and examine the crankshaft and your wallet. Let me know how you get on and will suggest the next move. Don't worry too much its probably something simple !! like an air leak, get some easy start and very carefull (with a fire extinguisher to hand) spray arround all the areas where such a leak could occure, I had a bad one around the big flexible pipe going into the throttle valve, if the revs increase you have found it. BUT be very careful.

ps must have missed something, but the chaps and girls on here will pick that up!