97 3500 6.5 running rough

[Lumbee89]

I bough this truck as a project, so far I've replaced pmd with remote mount behind front bumper on a heat sink, new fuel filter and cleaned the tank, fuel pressure at idle is 7psi, replaced return line on IP with clear tube and no bubbles, clear tube off t handle while truck is running and no bubbles. Truck starts right up, but runs horrible. It has a manual transmission and you cant drive the truck at all bc the throttle is touchy. Barely hitting the throttle will cause the rpms to redline and sometimes get stuck and you have to shut down the engine. No ses light on , I'm stumped

[DmaxMaverick]

Welcome aboard!

I hate to be the bearer of bad news, but if the STS (Service Throttle Soon) lamp isn't on, with accompanying codes, the PMD isn't suspect, and you have no other DTC's to work with, the IP is likely done. Check for current DTC's (SES lamp should be on), and any that may be in history.

[Robyn]

I agree with Maverick....
My feeling with these symptoms is that the fuel solenoid (inside the injection pump) is likely worn out.

Pretty much the only fix is to get the pump rebuilt or replace with a new one OR a known good one.

If you decide to get your pump rebuilt do yourself a big favor...... make a sharp scribe mark across the top flange of the IP and the timing cover where the two mate (USE A SMALL STRAIGHT EDGE AND A SCRIBE)

This will get your pump back on in a spot that the computer SHOULD be able to set the timing .... This trick can many times save one from having to do the TDC LEARN procedure.

I am puzzled though that with the thing running so bad that the SES lamp is not lit up ????

Does the check engine lamp come on when you turn the key on before starting ????

If not...may be the lamp is not working ?????

Have you plugged a scan tool into the rig to see if there are codes ????

[Lumbee89]

I was thinking the ip but was just unsure, the ses light does work bc I can unhook certain sensors and it will illuminate. And I have a programmer for my other rig that can read codes or do I need a certain scan tool for the 6.5?

[DmaxMaverick]

Many programmers work with older models, but some are model year or series specific. Plug it and give it a try. If it can communicate without errors, it will likely be helpful. Your 97 is a first generation OBD-II, so the code list is fairly short compared to the rolling super computers of today. Otherwise, you can use an ELM327 type adapter (cheap -ebay, Amazon) and a smartphone to do what you need. Let us know what you have and what you can do with it.

[Lumbee89]

Sure thing, I'm going outside in a few and I'll post what I find

[Lumbee89]

My sct tuner will not read the codes if there was any stored

[DmaxMaverick]

That may be useful information. Does it connect and attempt to read, or does it not connect or not respond at all? Most diag. ports prior to 2003 need to have the key on or it won't power a device that doesn't have independent power. Many will power the device, but the ECM/PCM won't communicate with key OFF.

[Lumbee89]

It will power up and attempt to read but it pops up unable to read FTC