Code 34 and 49 need some help

[Acesneights1]

I was down on LI this weekend helping a buddy with a few 6.5s he had. He has a 94 k3500 4dr dually. He asked me to look at it. Don't have much history on it but here's the symptoms and here is what I found upon inspection.
Truck is a little rough starting it was around 75 degrees out. Once started very loud. An even kind of loud not a singualr knock but just real marlbaly like a 6.5 would sound on a -5 degree day not plugged in. Truck has 191k on it and no history of when and if injectors or pump were ever done but it has an SS verion of PMD(sink on manifold with standyne PMD) I gave him a lecture about that and showed him mine. He said the truck is a dog but it was blocked in so we didn't road test. I notice alot of black smoke when dry revved it. Put GMCTDscan on it.Before starting had dtc 34 stepper motor and dtc 49 service throttle light. Cleared codes and started engine. Tried to read DTCs again but would not read DTCs while the truck was running. ONly after I shut it off then turned key to on.
When I read it again had same codes but as historic. Once he truck was warm I tried running it up to 2000 rpm and I could not hold it there plus it fel like it had a step off when trying to bring rpms slowly back down. I'm thinking pump and injectors ?? I am no longer in NY so any further info I would have to have him gather. He does not have GMCTDScan.

 

[chrisk1500]

Clear the historic codes.

Check to ensure TSM movement with a buddy giving the throttle a quick 'blip'

 

[Acesneights1]

Unless there is more than one way to clear codes I think I did that . I used the "clear all codes" on GMTDscan and they came back. Can you read codes while the truck is running ? I tried to explain to him about TSM but he at that point said I might as well change the IP. I said if it has 191k original it may not hurt but I would rather know that is the problem.What does the code 49 service throttle soon lamp mean ? The bulb is bad or something else ?
I took him for a ride in my Tahoe and he was in disbelief over how fast it was. I told him about your truck running 16s.

 

[gmctd]

191kmi?????? TIMING CHAINSET and HARMONIC BALANCER and timing cover seal and CPS and IP and injectors and OPS and Lift Pump and filters and accessory drive pulley and TDR url and .................

 

[chrisk1500]

Try forcing the lamp 'on' with the scanner - that will answer that question....

JD is right about the chainset....that truck is getting a little experienced...

 

[chrisk1500]

BTW - you can read and clear codes while the truck is running....

 

[Acesneights1]

BTW - you can read and clear codes while the truck is running....

That's what I thought but have only used GMTDscan a few times. So he may have other issues. I will pass on recommendations because that truck for him is a keeper.