96 K2500 454 engine starts then stalls then hard to start DTC - P1351
 

Hello! Thanks in advance for any assistance. As the title states, 1996 Suburban K2500 454 with about 265K. Engine starts then stalls immediately. Engine hard to start afterword and CEL on. P1351 (Ignition control module circuit high voltage) Engine starts and runs fine after about 10 seconds of cranking. Was only happening about once a week so it didn't concern me much but now its happening every day or twice in a day.

Also, although possibly not related, engine has a random misfire at low idle with about 5% throttle and goes away when additional throttle applied. Fuel mileage has gone down as well.

From what I've gathered and checked/replaced:

Possible bad ICM. Replaced with no change. Harness ok and connections look fine.

I have replaced the spark plugs, plug wires, ignition coil, cap and rotor.

Has anyone else experienced this? Any suggestions? The only other thing I can find mentions a false P1351 generated from a leaking fuel injector. Can anyone confirm that could cause this? My next step is probably going to be buying a fuel pressure gauge and checking for pressure loss when sitting.

Thanks again!

Yeah, it's likely the fuel presure regulator, or worse, a bad fuel pump. Dont know about the leaking fuel injector, but its possible, although it is less likely then the former two issues, IMO.

Same exact problem with same exact motor
 

Hello i have the exact same issue, I have replaced everything that it could have been and more! Even down to replacing the ecm and every sensor, still no fix. The only thing I haven't replaced is the injectors. Have you fixed your problem? I will eventually get the injectors replaced to see if that's what it is i will comment back here if it does thanks!
I have also replaced the fuel regulator and fuel pump.

Still dealing with this issue...
 

I still have this issue. I pulled the entire top end off. Replaced every sensor (maf, tps, iac, cps, coolant temp etc). I pulled the injectors and replaced the orings since the injectors themselves looked fine. I replaced the fuel pressure regulator, the fuel pump, fuel filter, I even replaced every ignition component with MSD including an msd ignition control box. New spark plugs as well. Still no change. I don't know where to go next.

I replaced my injectors, it was the problem! So it does throw a false p1351 I guess because of the extended cranking is why. Bun nonetheless it solved the issue! If you dont want to spend 800 dollars to replace the injectors you can get lucky by pulling each spark plug and looking for wetness also with a smell of raw fuel. It can tell you which injector is bad. Another way if you take the manifold off and take off the fuel rail injectors still plugged in to the rail and cycle your key to build pressure then put your finger over the sprayer end of the injectors you will see fuel coming out on your finger not much but enough to wet your finger.