p38 engine Judder/ revs serging HELP

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bezop38

New Member
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hi guys so i really need some help with my p38.
my dads just purchased a 1996 range rover p38 2.5dt manual BMW engined off ebay.
after not really knowing anything about them and have never owned one we was never too sure but with full service history etc we thought it was a good idea. turns out we bought a ****ter.
so i need help with...
while ticking over the revs serge under and over 1000rpm
sometimes does struggle to start sometimes you have to hold the throttle to the floor to fire up
second. while driving very slow with just resting my foot on the accelerator it drives lovely and if you drive it like you stole it it smokes alot but still drivers superb. but if you driver sensibly around 2000rpm doing 30mph 40mph speed limits it does this horrible judder/jumping almost asif your running it on kangeroo diesel or something. if you slip the clutch slightly and let the revs build up the judder stops. but i dont want to have to do that everywhere and then end up messing the clutch up.
so ive tried unplugging the air flow meter and there was no change to revs or running. so i am going to change that because im guessing thats nakered but in mine and my dads eyes that wouldn't make it do this judder/jumping while driving and that it will only be making it do the serging of the revs.
it has history of the tank pump being replaced plus lines and returns pipes. engine looks very clean with history of services oils plugs etc you know what i mean. everything else works as it should and really is a clean and nice p38
its just the BMW engine letting it down.. i would really appreciate any help or advice with this please as i need to get it sorted regards Ryan...
 
As Wammers said, diagnostics. IMO someone has been at the FIP.

+2 the FIP needs to be set to thousandths of an inch with a dial gauge - there are plenty of muppets out there thinking they can do it "by eye". Even if you get it running okay like that it'll still be miles out.
 
hi guys so i really need some help with my p38.
my dads just purchased a 1996 range rover p38 2.5dt manual BMW engined off ebay.
after not really knowing anything about them and have never owned one we was never too sure but with full service history etc we thought it was a good idea. turns out we bought a ****ter.
so i need help with...
while ticking over the revs serge under and over 1000rpm
sometimes does struggle to start sometimes you have to hold the throttle to the floor to fire up
second. while driving very slow with just resting my foot on the accelerator it drives lovely and if you drive it like you stole it it smokes alot but still drivers superb. but if you driver sensibly around 2000rpm doing 30mph 40mph speed limits it does this horrible judder/jumping almost asif your running it on kangeroo diesel or something. if you slip the clutch slightly and let the revs build up the judder stops. but i dont want to have to do that everywhere and then end up messing the clutch up.
so ive tried unplugging the air flow meter and there was no change to revs or running. so i am going to change that because im guessing thats nakered but in mine and my dads eyes that wouldn't make it do this judder/jumping while driving and that it will only be making it do the serging of the revs.
it has history of the tank pump being replaced plus lines and returns pipes. engine looks very clean with history of services oils plugs etc you know what i mean. everything else works as it should and really is a clean and nice p38
its just the BMW engine letting it down.. i would really appreciate any help or advice with this please as i need to get it sorted regards Ryan...

Don't bother changing the MAF waste of time and money, IF you can get one. It only controls the EGR.
 
Don't bother changing the MAF waste of time and money, IF you can get one. It only controls the EGR.
Here we go again, but this time you are right, changing the MAF for that problem will do nothing. Disabling the EGR and ensuring it's closed would do more but is not likely to be the cause either.
 
Here we go again, but this time you are right, changing the MAF for that problem will do nothing. Disabling the EGR and ensuring it's closed would do more but is not likely to be the cause either.

Keith the MAF monitors airflow so the ECU knows how much exhaust gas is being released into the manifold at any particular time. More air flow through MAF less exhaust gas, less airflow through MAF more exhaust gas. Simple as that it has no fueling loop.
 
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