Peterbilt 386 starts and dies immediately

[shawn21998]

(11-16-2023 )Rawze Wrote:  

(11-16-2023 )shawn21998 Wrote:  ...
I got the new ECM and unfortunately the truck still has the same issue. Still trying to figure it out... The only active code is SPN 168 FMI 1 SAE- Battery potential (Voltage) Data valid but below normal operational range - Most severe level. From component #128. I can't find any info on that code or what component 128 is.

What is the fuel pressure and oil showing while cranking?... and after, as it dies?.

What is the ecm voltage while cranking?>,.. and after, when it dies?.

Also, what does the Insite software show for active and inactive faults instead of some after-garbage SPN-type code reader?.

Fuel pressure while cranking 6300psi, up to 7400psi when it runs then drops out to around 2000psi after it dies. Oil pressure is 2psi while cranking then 10.5psi when it fires. ECM voltage while cranking drops to 8.5 from battery voltage while key switch voltage stays at 11 at ECM. Jumps up to 11 when it starts then dies. Component #128 voltage drops to 8.5 as well. There is no active or inactive codes on Insite. Jpro is showing low voltage codes from EC-60 ABS and component #128. Using jpro while monitoring voltages it shows the component #128 being CECU3.