m20b25 not quite right

[BavBeater85]

Hey, Ive recently swapped a m20b25 into my 85 325e...it has 19# mustang injectors and a mark d chip for 93 octane but is otherwise stock...I did just add a deatschwerks 255 fp and put a new 3 bar fpr on it...problem is I seem to have some misfire which first showed itself by variations in the torque reading on the dyno, but the numbers were strong at 145hp and 185 tq...today I pulled the plugs and they show signs of running too rich and detonation...any ideas?

[BavBeater85]

also she does have some stutter on acceleration and occasionally idle varies a bit. I at first was thinkin Im running too much fuel, but as Im overthinking it, now Im not sure if its crappy fuel, timing is advanced too far, running too rich or a combo of all three....has anyone ever had issues with the mark D chip because I def got the one for 19# injectors and 93 octane, which I always put in the car

[BavBeater85]

also pulls a 0a code, which I believe is air/fuel ratio is either too rich or too lean

[dnguyen1963]

vacuum leak is most likely your problem.

[BavBeater85]

huh....thinkin it must be internal then, because all of the hoses are new or tight, though I do hear a hollow hissing that sounds like its coming from inside the tb....gonna haveta get it smoke tested tomorrow

[jlevie]

Is the chip tuned for 19lb injectors? Just tossing those injectors in with a chip meant for 14lb injectors isn't going to yield a good result. You did replace the DME with one for an M20B25 (and the harness & AFM) when you did the swap, right?

There is no way an M20B25 engine is going to make 185ft-lb torque, so I have my doubts about the dyno data.

[BavBeater85]

yeah, mark d 19# chip with 7100 rev limit, and the dme is the 1.3 173....but like i said the torque numbers were a bit quirky, dude said he had trouble with the distributor set up...its just a mathematical number anyway

[BavBeater85]

but yeah, I ordered the chip from Mark d'Sylvias site to my required specs