View Full Version : light throttle misfire

02-18-2007, 11:32 AM
Ok, so I took my 86 out last night to run and get some tools to work on my 87. The 86 hasn't been driven in about a week, and it ran fine then. Last night, I realized that it's sputtering around 2500rpm while cruising (4.10lsd). So I started expiramenting more with it, and by the time I made it back to my house, it would do it most of the way through 1st and medium throttle, but in 2nd and 3rd at full throttle, it ran good. So basically I'm fighting a misfire that goes away at full throttle. Has anyone run into this problem?

specs: m20b27, ported eta head, 283 cam, 325i intake, exhaust, afm, wiring, 173 ecu, 19# injectors.

Today I plan on pulling a couple plugs to see what they look like, and I'll prolly swap in my m30 afm to see if that helps at all.

02-18-2007, 06:53 PM
My current thought is that it had something to do with the afm. I swapped in an m30 one with the stock air box and a new intake boot and icv, and all is peachy. Runs good now, I'll get new plugs on monday for it cause the current ones are black anyway.

02-18-2007, 11:22 PM
Misfire or afterfire.