1997 Chevy Truck P1351 and P0302: Hard start, Hesitation, S

The ICM you replaced same part number? Check terminals and connection. P1351 is high circuit voltage in the ICM. Verfiy spark to cyl 2 and voltage to injector easier with Noid Light. Check fuel pressure

Hi Docfixit, I put back the old original ICM (because I think it still good, I replaced it by guessing with the one from Autozone) and it clear P1351 (hope it don't come back), clear the code, drive around a block couple time, then scan again, I still have P0302, I though I replace # 2 Injector it should take care of P0302? but it not. So I might still have problem with # 2 cyl? but if it missing only # 2 it should not be that bad, at idle it misfire, (seem like more then 1 cyl) then smooth out at high rpm, it hard start in the morning, take 3,4 time before it start, when driving, step on gas it stumbles, stutter, then at around 10 to 20 mph it shoots up to 30 to 40 mph. Almost as if something was stuck in the airflow or something was restricting the system?

Check compression and get some MAF cleaner and clean it

Yes, clean MAF did help with start up, it start right up. But compression good, still get P0302? and at idle it misfire, (seem like more then 1 cyl), when driving, step on gas it stumbles, stutter?

Well where making progress. If not a big hassle switch Inj #2 with another see if code follows inj.

Hi Docfixit, I still working on my truck on the weekend and still have problem. I currently have code P0300 and don’t known what it could be, since P0300 not clear or point to any component? Still rough idle, hesitation, stumble when step on gas from 15 to 25 mph, get better from 25 to 70 mph but still can feel little misfire. What else can I try? Please help.

Hi
P0300 is multiple cylinder missfires by far the toughest code to solve. Most common is low fuel pressure check pressure must be 60-66 psi.

Hi Docfixit, the fuel pressure is 52 psi and step on the pedal it jump to 57, is that low is nough to cause code P0300, rough idle, hesitation, stumble when step on gas? is fuel pump bad?

Well according to Chevy if not at least 60 psi replace regulator if still not 60 psi replace pump.