[shiftspark]

I have a lightened flywheel and 15 pulley and it hasn't been mapped yet but runs as normal except it needs slightly more revs when pulling away from stand still.

 

[NigelStap]

I have a lightened flywheel and 15 pulley and it hasn't been mapped yet but runs as normal except it needs slightly more revs when pulling away from stand still.

mine was OK with the SMF before the cam was fitted.

 

[CarsOrBikes]

lighter flywheel might speed up the idle more than slow it, less drag

 

[NigelStap]

lighter flywheel might speed up the idle more than slow it, less drag

It's not the idle that's the problem. When the engine speed reduces the lighter flywheel has less stored energy, with the clutch pedal pressed down the revs drop quickly enough that the ECU doesn't catch the engine at idle speed and it dips below, sometimes enough to stall.

Leave the car standing idling and it is OK, it will not stall.

 

[KeithyCoop]

It's not the idle that's the problem. When the engine speed reduces the lighter flywheel has less stored energy, with the clutch pedal pressed down the revs drop quickly enough that the ECU doesn't catch the engine at idle speed and it dips below, sometimes enough to stall.

Leave the car standing idling and it is OK, it will not stall.

Still makes me wonder if the bypass valve is not opening quickly enough? has it been cleaned, I know it’s working.

 

[CarsOrBikes]

It doesn't hold it's revs at idle when hot. Start it up after it's stalled and it ticks over fine. Changed the throttle body but it has made no difference.

ok gotcha, read the above as a low idle more than the 'return to idle',

 

[CarsOrBikes]

fwiw it's harder to resolve on the earlier software which has fewer tables to adjust, the 06 version has around 50% more not that all would be relevant to this issue, even then it takes fine tuning on the road from 1320 to help minimise it, not usually an issue for a PH2, what's your idle set to?

 

[NigelStap]

My C310 reader showed an idle value set at 750rpm. I think the cam and SMF combo may need an extra 50rpm.

 

[NigelStap]

I did some digging around today and unplugged sensors one by one and drove the car in between. Both MAP sensors were fine, which I expected. However my short term fuel trim was way out when everything was connected. I unplugged the pre cat lambda and bingo it ran and idled much better. I think I've found the culprit. New sensor ordered as well as a special socket to remove and fit.

Fingers crossed.

 

[NigelStap]

New sensor fitted. Fuel trims are better but it still stalls.

Going to swap out the fuel tank vent solenoid (front left of the engine above the supercharger). Easy to do and can cause the symptoms.