Dchampn

New to the forum but I've had a problem lately with my 99 Si. I'm getting a CEL code of misfire 1, 2, 3, and 4 also multiple misfires. I've replace the distributor with an oem replace, adjusted valves (none were loose), cleaned injectors, replace fuel filter, and sprayed IAC valve (idle was still rough after this). Idle is rough, engine shakes when accelerating but this all only happens when at normal operating temp. When cold idle is fine and not flucuating, but once warm it runs horrible! Please help lost what to do next

go-part

I would suggest getting those codes read before you go replacing parts.

Looks like your issue is timing related..

Dchampn

Ok I'll gather the codes and get back to you with them. If the timing was off what do I need to do to fix it, just get it retimed?

Dchampn

Also when warm and fluctuating idle and active misfire the misfire stops if I turn the heat on or give it a little gas to hold the RPM around 1200. When I do that it smooths out