Lumpy idle and cutting out

[Rich_G40]

I've not long ago got the g40 up and running for the road. Took it to the rolling road on saturday to get it set up, Ran like a dream producing standard figures for a sort of stock setup (running boost return and blended charger)

Then Sunday half way through the day I was sitting outside a mates house with the car ticking over and the idle started to die (battery light flicking on and off)

Took it out for a run and it didnt like going slow and was putting out some black smoke from the tailpipe. It boosted up fine but doesnt idle very well or run smooth.

Started the car up the other day, it ran fine for a minute then went all lumpy and died after 30 secs or so.

What Ive checked:

Battery charging while running 13.8 volts
Compression checked the pistons and added oil aswell to check for ring wear (all fine just over 10 bar)

Took the injectors out and put ignition on to see if the injectors are weeping
Turned the car over with the injectors out and there firing fine
co pot is set at 600kohms
changed blue temp sensor
no boost leaks
still boosts to .5 bar(how its always ran with a stock pulley)
spark plugs look in good condition just black sutt
dizzy number 0 0237 521 048 bosch and looks in good condition
points in the dizzy cap look fine.number on the dizzy cap 030905237x
Took the lamda sensor out and cleaned but it only passed the mot 2 weeks ago and the emissions were fine.
Checked earth leads (going to renew on friday)

Still the problem persists

[PeteG40]

just thinking about this - whats the battery putting out when not running.  Mine was charging, and putting out ok volts, but was 100x better after i'd charged the battery on a house charger.


ps - thought you had a stock pulley - not 68mm?!

[Rich_G40]

Will check when I get home.....My bad on the pulley... its the same size as when you last seen it. Stock

Changed the post

How does the ISV work. Any way of checking operation?
I know its in a crappy place to get too.lol

[vwmk3jon]

ISVs not too hard to get out but can be a fiddly bugger to put back in again!

Give it a good clean out (i used wd40 but other people use different stuff) and then try again.

[Rich_G40]

Might have a nosey at that later 

[PeteG40]

what brand and model of plugs are you running?

[Rich_G40]

NGK
BP7 EVX

Battery sits at 12.6 volts.

just taking out the isv thingy

[Rich_G40]

There was a little bit of oil in the isv, cleaned it out with sum wd40?
Going to add my home made earth straps later and fit isv will keep you guys posted.

[G40supercharged]

The ISV "idle stabilisation valve" is actually an "auxilliary air valve" and doesn't control the idle. It just lets in extra air when the car is cold. When fully warmed up you should be able to block the pipe to it completely with no affect on idle (try squeezing pipe closed between your fingers and see if engine reacts). Idle is controlled by the ECU making adjustments to the timing. I would try some new ignition leads if you haven't already.

[Rich_G40]

Thanks fella.
Ive got my inline adaptor for the spark plugs to see if there firing. Will try it later.
At least Ive learnt what that does. Cheers

[Rich_G40]

Right..................................

Upon putting the ISV back I noticed the live wire that goes from the battery to the starter motor had been rubbing on the steering rack. That is now sorted, but it was still cutting out. I have changed the HT Leads and now runs ok.


It still hunts a little on the revs 900-1200 but other than than its spot on

[PeteG40]

hunting - can be timing or idle screw.

[Rich_G40]

cheers for all the help guys

and the 2 latest editions pete