Wyked88
Member
2008 LMM … just replaced engine (used).. and came across info that i needed to re-program injector flow rates .. GPCM was not with replacement engine. anyway, i came across this looking into a SLIGHTLY rough idle. so, i programmed the injectors into the ECM/GPCM and the idle remained a bit shaky. everyone says its fine, but i know MY truck, and it just doesn’t seem right. so looking at the injector flow rates, i noticed one seems a bit out of whack. everything i’ve read (including AllData and multiple other threads) that “good” is -4 to +4 … i’ve attached an image of my #s … CYL. 4 seems a bit high. this is @ operating temp, a/c and all accessories off. ideas? opinions? next steps? just swap it with one off my old engine, and see what happens? when i did a CYL. Balance test, it seems to all be within spec. 