8v Griso persisent misfire

[Trogladyte]

This is puzzling me.

For a while I've had the classic running on one when wet symptoms. Its been getting worse, so I thought I'd better tackle it. The issue is on the left cylinder.

 I'm already running NGK plug caps but I got some new ones anyway. Fitted  new cap and new HT lead, but even in the dry I'm still getting a slight misfire - misses a few beats at low revs after changing up from time to time. I can't see any signs of arcing and I can't see any arcing when running in the dark.

What's next?

Incidentally, I don't understand how Fowlers can justify £50 of your Eengleesh pounds for an HT lead. I mean, for real? I ddn't pay that - I got a length of HT lead from Gutsibits. And £670 for a full loom. R.U. Sirius?

[beetle]

Check the ECU connector for corrosion?

[lucian]

Are you sure it's a misfire, or maybe a cough or hiccup back through the throttle bodies. Has the sacred stop screw been tampered with?

[beetle]

Yeah. ^^^^^^. What lucian said.

[pete roper]

Excessive lean-ness will cause spitting back through the TB's. What map are you running if non-stock? If you're running the stock closed loop map any messing with the throttle stop screws or linkage rod can cause a host of problems as its already trimming down to lean as buggery.

Pete

[Huzo]

An old fashioned approach I admit, but is it possible to change the 12 V feed to the opposite coil/s and cross the plug leads to see if the failure moves to the other side ? Would positively eliminate coil and plug leads etc as a possible cause. Not conclusive, but if it's rpm related, more likely a fuelling issue ? I'm clueless in this area so I hope that wasn't too stupid. Are the plugs burning the same colour each side ?

[Huzo]

This is puzzling me.

For a while I've had the classic running on one when wet symptoms. Its been getting worse, so I thought I'd better tackle it. The issue is on the left cylinder.

 I'm already running NGK plug caps but I got some new ones anyway. Fitted  new cap and new HT lead, but even in the dry I'm still getting a slight misfire - misses a few beats at low revs after changing up from time to time. I can't see any signs of arcing and I can't see any arcing when running in the dark.

What's next?

Incidentally, I don't understand how Fowlers can justify £50 of your Eengleesh pounds for an HT lead. I mean, for real? I ddn't pay that - I got a length of HT lead from Gutsibits. And £670 for a full loom. R.U. Sirius?

Worth getting Paul from Corsa to check it out ? He's in Epsom.