Hey guys i signed up on this forum a while ago and never got on to it, and now im have problems with my 1990 300zx tt the car is stock no engine major engine mods it has a high flow intake, hard pipes, and a jim wolf upgraded ecu. I bought the car completely torn apart and the guy was complaing of a missfire before he stripped it down. When i brought it home i did all new gaskets new knock sensor and the sub harness, also a new engine harness and a ptu just because of there history. Put it all back together and it ran good, parked it for winter and went to bring it out the other day and it has a miss in cylinder 1 and 3.

i did a compression test that came out good
have spark in all of the cylinders, also switched coil packs to running cylinders and they worked fine
i have pulse at the connectors for the injectors also
run a diagnostic test and i got a code 34 (detenition sesor) is it throughing the code because of the misfire?

i also did notice the injectors in cylinder 1&3 have brown tops and the rest are the oem purple.

anything else i should check?

my thoughts are injectors but i wanna make sure before i spend that kind of money.

any help would be great thanks

 

OHM the injectors. If you have a miss on 1 and 3, and 1 and 3 have different injectors, that would be my guess.

 

I figured it would be my injectors. I tryed ohming them but my multimeter sucks so the reading just goes up and down never a constant reading.

 

Well the only reason he's having you get the reading of the resistance on the injectors is to narrow down the problem to whether it is an injector or not. I borrowed someone's multimeter to check mine and found I had a bad injector not too long ago so go ahead and do that or get a better multimeter.

 

injector in cylinder 3 ohmed to 30.2 and cylinder 1 12.6. looks like im buying some injectors.