Thread: Help needed.

Originally Posted by derpomz

Just cam back from a shortish trip, i have found the Rangie is idling a bit rough.

How do you adjust the idle on these P38,s.

I don't think you can. It's all controlled from the ECU's preset setting i'm pretty sure. However i'd be looking towards a MAF sensor clean, check the stepper motor for carbon build up & spraying some carbon cleaner down the inlet plenum and give the butterfly valve a wipe. If this doesn't fix it, then it could be time to have a look at your spark plugs & leads.

Testbook (and other diagnostic gear) can reset the idle but if it was fine before & not now, check out the suggestions above first.

If it's ideling rough I'd be looking at a vacuum leak somewhere. Is it gems or bosch?

If gems, the fuel pressure vacuum pipe and the pcv pipe on the driver's side cover can be culprits.

Gems idle is adjusted by an Allen key on the inlet manifold, but to do it properly you need diagnostics, as the stepper motor should be at 12 steps at 750rpm (aircon off etc.)

If it were ideling good before hand if day something is a miss as opposed to bad idle setting.

If the idle is bouncing up and down this can signify that the stepper motor plunger needs cleaning (must keep the ignition of when doing this! )

Sent from my GT-I9305T using AULRO mobile app

I had a rough idle that was getting worse, ended up being build up on the butterfly valve.
Very easy fix, take off the air inlet hose and spray throttle body and carby cleaner onto the valve, move it open by hand and use a clean rag to get all around the edge.
That's what worked for me, I do that as part of my maintenance now if it needs it or not.

[QUOTE=redandy3575;2189510]I don't think you can. It's all controlled from the ECU's preset setting i'm pretty sure. However i'd be looking towards a MAF sensor clean, check the stepper motor for carbon build up & spraying some carbon cleaner down the inlet plenum and give the butterfly valve a wipe. If this doesn't fix it, then it could be time to have a look at your spark plugs & leads.[/QUOT

Ok thats fine................WHAT THE HELL ARE YOU TALKING ABOUT.

I am new to this Rangie stuff and have no idea what you have said. Can you please explain what all this means so i can work it out.

Do you have a copy of a document called RAVE? It's a land rover publication obtainable in pdf format online ...for free if you search hard enough, or for a few $ see home page of this forum... it contans over 1500 pages of searchable information on how to do almost anything on a Range Rover / Disco / Defender etc. It has at the beginning of each section a detailed, plain english description of the relevant system,how it works etc.

Once you have an understanding of how stuff works the life of a LR owner takes on a whole new meaning You learn to use words and concepts you never thought possible!

Having lived inthe ACT for almost 2 decades ...that was 2 decades ago to know what I now now about LRs and P38s in particular.. I could well become The Captain of the Queen's Nav-ee so if you are seeking worldly fame and promotion... study land rovers! You will learn about complexity theory, string theory, politics ... just read it...RAVE I mean...