Missfire, whats going on?

[wizzer]

My S2 has been running well for ages now, this evening having run about 4 miles as normal I changed down for a slow bend. As I tried to apply power there was a loud back fire and a loss of power, just enough power to move the car off the road with a lot of back fireing. The car was ticking over but very lumpy, as I blipped the throttle the engine cut out. After a minute or so I started the engine and it ran as normal. Now I cant replicate the fault in an effort to trace the problem. All I did before restarting the engine was push all the plug and dizzy leads to make sure they was on tight. Any thoughts as to the cause, now I'm waiting for it to happen again at some inconvenient moment.

Edited by wizzer on Wednesday 28th September 09:35

[ketvrin]

Coil to dissy lead ?

K ;-)

[GreenV8S]

Massive loss of power but still running makes me suspect fuelling - if the load sensor has failed the engine will have enough fuel going in to idle (roughly) but as you open the throttle the engine leans out and goes flatter and flatter.

I had a hotwire sensor fail on my V8S, and it would idle a bit lumpily but nothing happened when the throttle was opened. It would literally sit at full throttle full boost barely above tickover producing no power at all - but still running. Then an occasional dab of the throttle would throw in enough fuel to get it to run properly for a moment so it would spin the wheels in whatever gear it was in, and then immediately go back to taking-the-pi$$ mode. It was utterly bizarre to drive.

So, if you have the flapper style AFMs I'd check the electrical connector on the one that's being used.