Help! I have a p38 problem!

My p38 4.0 petrol has an idle problem.. there far too low and has a tendensy to cut out
When I slow down for example.. when I park or slow at a junction.
Can anyone help?

i had this with mine, check the intake hose for leaks/splits after the MAF. could be letting in too much air after the ECU has decided how much fuel to inject.

my garage also re sealed my plenum chamber as that was leaking air in

First thing comes to mind would be Idle Air Control Valve.

:5biagree: Remove and clean may do the trick. Happened to me a month ago nice cheap fix

gibby_wls said:

i had this with mine, check the intake hose for leaks/splits after the MAF. could be letting in too much air after the ECU has decided how much fuel to inject.

my garage also re sealed my plenum chamber as that was leaking air in

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That would make it rev higher not lower.

I'm with Martyn on that one. The idle control needs a good clean & freeing up. It'd be a good start before you look at other areas.

It makes it run lumpy where the ECU is struggling to compensate.

I started with that on mine, but only found the split when i removed the hose form the MAF to plenum chamber, it was in one of the ridges on the underside of the hose

Thanks for the help guys! one problem being Im rather new to all of this and wouldn't know where to find the Idle air control valve.. any chance of trying to explain where ill find it?

P.S Martynv8 Your P38 looks amazing! need to have a look at more pics and find out where to get some of the nice add ons!

As far as I can remember on the GEMS Engine it is screwed into the plenum on the top of the engine on the side closest to the firewall....



Item 16 in the attached parts image

Saint.V8 said:

As far as I can remember on the GEMS Engine it is screwed into the plenum on the top of the engine on the side closest to the firewall....

Item 16 in the attached parts image

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Thanks mate I'll try and give it a go when I get a chance.
Scared I cause more bad than good.. gotta start somewhere though!
Thanks again for the info.. have you got a p38?

mike91 said:

Thanks mate I'll try and give it a go when I get a chance.
Scared I cause more bad than good.. gotta start somewhere though!
Thanks again for the info.. have you got a p38?

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I have had 3 P38's previously - 2x 4.6 HSE's and a 2.5 DSE....awesome machines....if my L322 hadn't have come along at the right price at the right time....I'd still have my DSE....love 'em to bits!