While driving home today in my Sapph 4x4 Cos I played with a ST220 and i felt a tiny/"smooth" misfire at high boost.

However, everytime i booted it the misfire got worse and occured lower down, it got to the point that it almost cuts out when it reach positive boost.

The misfire aint as brutal as the boost limiter or "blown out" spark, its more like its almost cuts out and the comes back on again just to cut out once again. Its pretty much undrivable at boost.

Any ideas what to check? Could it be the plugs anyway?

Car is Sapph 4x4 Cos running stage 3.

/Andreas

[Edited by Reckie - 9/14/2003 5:21:05 PM]

Hi Andreas..;)...Try plugs first mate,then take it from there..:)

Phil H

Plugs first,dizzy cap and arm,then i would go for the leads as it sounds like an ignition problem.

I had the same problem acouple of years ago and it turned out to be the distributor its self :(

My old three door did that. Took it to Power and Mervin sorted an eaten plug in a jiffy. check yours first off.
astraboy.

Andreas,

Check all of the above as listed, but also make sure your lead from coil to dizzy isn't anywhere near the MAP sensor.

What affect does that have rich, and how close is too close ?

Cheers for the help, will go have look right away.

I tried being bufty so i cleaned the panels below and around the coil, also pulled some HT-leads so perhaps i broke something.

Update: looks like Rich could be right about HT-lead to close to MAP-sensor. The clip that holds it togheter with another hose had come loose so its possible for the lead to move closer to the sensor by air drag or accelleration.



[Edited by Reckie - 9/15/2003 11:46:58 AM]

I agree that it's probably just eaten a plug. Common on high boost cars I think.

Paul