P38 Diesel - Lumpy Idle on Warm Start Up

Hello All,

I'm off for 3000 mile road trip around europe on friday in my 1997 Range Rover DSE.

Unfortunately it seems to have developed a lumpy idle on warm start up. When i say lumpy i mean severely lumpy, like its running on 5, 4 maybe even 3 cylinders. Its clearly not just misfiring however as all i have to do to resolve it is hold it at 2000rpm (which sounds absolutely normal) for 30 sec and she returns to idle normally.

It hasnt done it yet on cold start up, but i have only had her for a week.

I would say it sounds like when you start and engine and it hasnt got enough fuel, and i have read that they can suffer with air in the fuel?

Any ideas as to what it could be? and how i can test to find out if it is?

Any help is much appreciated.

Im currently in Norfolk/Suffolk if anyone is nearby to listen.

Anthony Day said:

Hello All,

I'm off for 3000 mile road trip around europe on friday in my 1997 Range Rover DSE.

Unfortunately it seems to have developed a lumpy idle on warm start up. When i say lumpy i mean severely lumpy, like its running on 5, 4 maybe even 3 cylinders. Its clearly not just misfiring however as all i have to do to resolve it is hold it at 2000rpm (which sounds absolutely normal) for 30 sec and she returns to idle normally.

It hasnt done it yet on cold start up, but i have only had her for a week.

I would say it sounds like when you start and engine and it hasnt got enough fuel, and i have read that they can suffer with air in the fuel?

Any ideas as to what it could be? and how i can test to find out if it is?

Any help is much appreciated.

Im currently in Norfolk/Suffolk if anyone is nearby to listen.

Click to expand...

Look for air in the clear pipe filter to pump. If you have any check the lift pump is working.

wammers said:

Look for air in the clear pipe filter to pump. If you have any check the lift pump is working.

Click to expand...

+1. If you look in the Technical section Wammers has done a How To test the lift pump.

I think the previous owner has removed the clear pipe filter, is it in the engine bay before the fuel filter?

After it. After the filter and before the FIP. Try cleaning it with some diesel or petrol as it can get pretty mucky.

Previous owner has fitted a one way valve before the filter. I will try find the clear one section and look for air.

Anthony Day said:

Previous owner has fitted a one way valve before the filter. I will try find the clear one section and look for air.

Click to expand...

Done you a favour there. The new lift-pumps don't have one but the older cars need one.