Idle , surge , die

[trap4x4]

Hi guys ... hoping for a quick trouble shoot.

Have a '94 6.5. It starts hard ( have to pump it) idles fine for about a minute , starts to surge(high and low idle) then dies. Try to feather the surge out and can sometime save it , but lacks sustained power.

changed the fuel filter without any change. This started after about a 200 mile trip...

Just looking for the most logical place to start replacing parts.

Thanks

 

[THEFERMANATOR]

First it would help us all if you fill out your signature so we know exactly what you have and what mods are on it. Next try and go through the 6.5 diagnostic checklist to help us narrow it down. And I'm moving this one to the 6.5 section where it is more appropriate.

 

[handcannon]

X2 on needing more info.

My first thought is air in the line. If it acts just like a gasser motor when it is running out of gas, then chances of air in the line are high.

Could also be very low fuel pressure. If the lift pump is not working your fuel pressure would be very low.

First thing, put a clear fuel line on the return coming out of the injection pump so you can check for air in the line. The return line is about 6" long and comes from the top of the IP and runs forward to a steel line that goes across the front of the motor. When the motor is running there should not be any bubbles moving through the line.

Do you have a pressure gauge you can install, even if it is just temporarily? Install it and report back what your startup, idle, and highway pressures are.

Don

 

[Turbine Doc]

From the tech library the diagnostic starting point http://www.thetruckstop.us/forum/showthread.php?6300-6-5-Engine-Diagnostic-Troubleshooting-Checklist


And also diagnostics for fuel system http://www.thetruckstop.us/forum/sh...t-Pumps-amp-OPS-operation-and-troubleshooting

 

[Turbine Doc]

Have a '94 6.5. It starts hard ( have to pump it) idles fine for about a minute , starts to surge(high and low idle) then dies. Try to feather the surge out and can sometime save it , but lacks sustained power.

"Pumping pedal" really has little effect as the IP on the 94 is electronic and APP sends electric signal to it vs. a mechanical connection via a pedal/cable like the mechanical IPs have, I suspect fuel delivery issue from lift pump.

Grounds also worth looking at http://www.thetruckstop.us/forum/showthread.php?17457-Grounds-what-are-they-amp-where-are-they