99 5.7 vortec P1351 Crank no start

[marinekilz]

Just looking for input right now, I will get to testing later in the week and update the post.

So I have a crank no start. Put fuel in the tb and it start but won't rev up. P1351 with no cel on. P1351 is for over voltage to the icm. Could low fuel pressure cause that fault to be set?? I will check fuel pressure on the truck as well as the signal to the icm making sure it is between 1-4 volt.

Has anyone come across this before?? Any input would be helpful!!! Am I missing/overlooking something?? Let me know please!!

Thanks in advance

 

[marinekilz]

So I got some testing done today.

fuel pressure 53psi priming to 55-57 when running or under load. I have seen two specs for fuel pressure 50-65 and 60-66.

Which fuel pressure range is correct??

Pressure bleds down to the 40-45 psi range after 10+ minutes.

Could lowered fuel pressure cause the p1351 fault??

so I followed the trouble shooting table for p1351. deleted fault. disconnected injector plug. cranked engine, code p1351 came right back. reconnected injector and disconnected the icm. checked ac voltage on terminal b on icm. voltage 1.6-1.9 within the 1-4 spec. checked ground on terminal c on icm. found 3.2 ohms resistance to the ground on the battery.

Is that normal for the ground on the back of the r/s cylinderhead to have so much resistance to the ground of the battery?

checked resistance from terminal c on icm to the wire connected to back of head and got .2 ohms. removed the cables from the cylinderhead ground and cleaned the connections. reinstalled ground and the resistance did improve to 3.0 ohms but that still seems alittle high to me.

Checked for proper voltage at terminals a and d on icm. found battery voltage with a 0.2 voltage drop.

Now the troubleshooting table advises to replace the icm.

Did I miss checking something?? Any opinions?? any advise?? Thanks in advance.

 

[lesterl]

I think the head grounds to the frame, then frame to battery, so clean the connections at the frame also... I dont think this is the issue tho.... Sounds like a bad ICM......????

 

[marinekilz]

I was thinking of of running an extra ground wire from the back of the head and routing it to the ground where the battery ground attaches too. Just to be safe. I got some thick gauge wire laying around somewhere.

Well we will see if it is the icm, It is a cheap part so I gonna just get it and keep my fingers crossed.

will update good or bad when the part comes in.