P38 looses power & stalls and the tickover is rough.

Hello one and all.
I was wondering if any of you chaps can help me out. My old man has bought a 1998 R-reg p38 Range Rover 2.5 diesel DSE manual which has done 122k, but he is having a few problems with it. Whilst driving the vehicle between gear changes the vehicle loose's power on occasion and stalls and the MIL light comes then goes off. Also when the car is warm it does not seem to tickover correctly, its off around 900rpm then drops down to 700/750 rpm and begins to hunt and the engine shakes and vibrates. If you blip the throttle it cures it for only about a couple of seconds and then it back to normal shaking. I have read a few posts on here and the first thing I went to check was the MAF sensor by the air filter but funny enough it is not there its just a black pipe. I don't think its anything to with with injectors or pumps, no air bubbles, no leaks. But I hope I am not right but I was thinking on more of the lines of the £££ DMF wheel£££ may be, or has anyone else got any ideas ?

Sounds like a fuelling problem to me....fuel Pump / Filter ect ..... I'd go for Filter myself as if you depress the accelerator, fuel pressure will increase forcing it thru the filter if (as you say) it "Won't Idle" so a "lower Fuel pressure won't force it thru the filter so... either low fuel pressure or more likley a blocked fuel filter

Yeah that seems like a valid point, I will have to check that out, Always go the cheap route first. But would fuel starvation cause the engine to really shake/vibrate and sound rough on idle, surly the engine would just cut out. The Range Rover is book in tomorrow at the local workshop for a diagnostic, So fingers cross the computer will come up with some error codes.

DaveEb14 said:

Yeah that seems like a valid point, I will have to check that out, Always go the cheap route first. But would fuel starvation cause the engine to really shake/vibrate and sound rough on idle, surly the engine would just cut out. The Range Rover is book in tomorrow at the local workshop for a diagnostic, So fingers cross the computer will come up with some error codes.

Click to expand...

I would imagine (I don't have a diesel, ANY engine shaped in a "V" be it 6,8 or 12 will do fer me!!!) that if its JUST getting enough fuel to run then it'll shake like a 1955 routemaster bus on a cobbled street!!!

You mentioned it "Hunts" therefore its "Looking fer fuel" but not getting any, but if you depress the Acc a bit it evens out, i.e its getting what its looking for.

YEAH!! gotta be a partially blocked fuel line/filter or a partially blocked injector..

So a new fuel filter, load of diesel and some injector cleaner and a bloody good run might do the trick. But when the rev's drop from 900rpm to 700/750 rpm on tickover and then the engine shakes rattles and hunts with a blip of the throttle it cures it for about 2 seconds but when you dip the clutch the engine still shakes and hunts but not as bad. Thats why I was thinking more of the lines of the problem being the dual mass flywheel because that could be messing with the timing of the engine.

DaveEb14 said:

So a new fuel filter, load of diesel and some injector cleaner and a bloody good run might do the trick. But when the rev's drop from 900rpm to 700/750 rpm on tickover and then the engine shakes rattles and hunts with a blip of the throttle it cures it for about 2 seconds but when you dip the clutch the engine still shakes and hunts but not as bad. Thats why I was thinking more of the lines of the problem being the dual mass flywheel because that could be messing with the timing of the engine.

Click to expand...

As you said Dave ... Easyist first (& Cheapest!!) ....swop out the fuel filter & chuck some injector cleaner thru it .... if its bin owned & run by some pussy whos never taken it over 50MPH then it will run DOG ROUGH!! go & Naill the fooker down the motorway ( Red line it in every gear) & watch the ****e fly outta the back...........Another thought occurred to me check out the EGR valve they are prone to sticking if it coughs & splutters AFTER a good run its usually the EGR stuck open ..... The Disco boys Blank em off (Not sure you can do that with the BMW engine)

with regards to the DMF .... I have seen posts, More on the Toyota & Ford forums (Amazons, Surfs & Land Cruisers ect +Mondeos & Transits ect) where guys have WELDED the DMF together !!!!

But lets concentrate on getting the Fuel right first....... Now, The suns just come out so forget it for today & go & sit in the garden wiv a beer (if the Mrs asks what yer up to just say ..... "Just planning what to do on the Rangie dear".....

Good Luck & lets us know the outcome ....

Keith

Fuel starvation wil certainly cause the idle to drop and the engine to shake. By MAF sensor I think you mean MAP sensor, manifold absolute pressure sensor. that does not affect idle on mine if the pipe is off the sensor. The other place to look is the MAF, mass air flow sensor in the air intake by the airfilter, that should show on the diagnostics. Fault codes is the place to start.
If you car has an EGR valve, thats another possible problem area.

if the air filter is blocked that can cause fueling problems and also check the turbo and intercooler hoses if they are split or loose that would make it down on power as well

Funny mine does that

The cut out bit
It only seems to do it when u short shift it, or change up at a low speed
( never happens to the missus but she obviously nails it harder than me)

did the shake thing but a good service cured that

good luck

Well chaps,
Just pick up the old range rover from the workshop from having a diagnostic today £50.00 later. No errors appeared on the computer. So far I have change some of the leak off pipes because they were a bit worn and inside they were all full of oil and ****, the RR seems to be behaving itself but I am not yet convinced. Check all hoses for cracks and splits etc. Cleaned all six pots where the injectors sit. I will be putting a new fuel filter in tomorrow and a one way valve to stop any air being drawn in, so the mixture isn't so weak in the mornings. Then I will give the old girl a good old red line thrashing. Thank you all for your comments I will let you know how I get on.