facets

Well, here's my problem. Hopefully someone out there can help me.
Since 8500km I have had a problem with my S2000 missing and flat spotting at 7000 RPM.
Honda have pulled the car apart and changed numerous sensors including 3 new clutches saying that the problem may have been balance problems setting the knock sensors off . All to no avail. 18months on and numerous changes in sensors they decided to check the spark plugs. What they found were fowled plugs with a rust coloured residue that they could not explain and blamed me for bad fuel.
As I have since found out, it is premium fuel that changes the burn colour and not bad fuel. I now have 65000 on the clock and the problem has started again.Number 3 pot has a different burn colour and fowls after a short period of time.We changed the position of the plug and ignition coil to another pot but no.3 still fowls to the point of running on 3 cylinders until I give it a bit of juice and it clears at low revs but still flat spots at 7000.We have changed the map sensor twice to no avail,had the injectors out, cleaned and tested 100% ok. The problems only happens after 10km of driving and only after I have taken it to 7000, if I drive around without engaging over 7000 no problem but once it starts it gets progresivly worse. Has anyone expierienced this or can nanyone offer suggestions to check.
I am booked in for a dyno on Friday. Should have some readings to gauge.

johninator

Try the water temp sensor and the 02 sensor. If the plugs are getting fouled, it may be that the ecu is not going into closed loop thus running richer.

facets

Thanks, I'll give them a try after the Dyno.

s2ksimon

pm xviper when you can

Barry in Wyoming

Compression check?
Bad rings on #3?
Just a guess. I'm a doctor, not a gear-head.

pjkwong

check with turbopwr
he had a problem with his car when he hits vtec