Change the CPS first. Bad timing data could be causing the other codes.
The other codes 370 and 251 are related to PMD or injection pump.
Many times when they show up together the IP is bad. But can also be caused by a bad PMD. You really need to get a resistor in the PMD. That may help. Its not good to run without the resistor.

 

hello tommygunner so today i changed the fuel filter and removed all the fuel in the housing and refilled while I primed the engine with the key on I removed like this cloudy brown diesel in my fuel filter housing I added honey product two days ago but that wouldn't make my diesel turn brown and did fuel up 75$ worth of diesel the day before all this started to happen but that still doesn't explain the lack of power in the system like with just getting up in speed I ran the truck today after replacing the fuel filter and the #5 resistor I order a number #9 that will be here Saturday with a brand new pmd but I reused my old/new one I bought off of amazon for 130$ and it ran better not bucking or misfiring but I still got a real lack of power and i got abs codes as well C0273 C0237C0266 but could that give me the other codes im getting on the engine side of the ECU.. this truck is stock no mods or updates expect for oil changed and fuel and oil filter I run 15w40 delvac all year round and same for my dad when he drove it... could all these code be happening due to the CPS and if so what do I do after replacing it because I hear you have to relearn the system with TDC and I don't have a tech 2 scanner I got a bluepoint code reader that only gives me 6 things to see and they are useless for me because I can see all that info on my dash RPM oil and 12v and temps but nothing for my timing or that could be useful for this issue with the relearn... I will be doing the CPS on Saturday and as well for the pmd and #9 resistor

side note doesn't the optical sensor acts as a back up for the CPS and if so could have I fired my optical sensor since it was the only thing keep everything in time and if so doesn't that mean a new sensor all around or did I just mess up my 6.5

 

Dont need a tech 2 to do a relearn. With OBD2 after CPS install you need to do the KOKO procedure.
If you dont know how Go here: Info: - The 6.5L FAQ's... The Master List of...
Scroll down to TDC offset. KOKO is covered in that section below.

 

I just read the KOKO system and found that you need a scan tool that can read the TDC mine bluepoint one doesn't and idk why so do I just wing it and do the CPS and then run it to 170 degrees then koko because now idk what Todo because I read the following list that said you should only do a KOKO is when replacing the engine or PCM or the front engine cover has been replaced and has well for the IP CPS was not on the list for the this KOKO

 

When you replace the CPS be sure to use AC/Delco brand only!
Aftermarket brands will bring issues

 

hello OkDually I just installed my CPS and yes is for sure a AcDelco part only one I will buy for my GM truck
as of right now I got to put back together what I toke off to get to it I removed the power steering bracket and as well the coolant housing since it was in the way when I tired to remove the power steering bracket but as of right I got everything put back together but I broke a part along the way so I gotta go out tomorrow and finish it
I will update y'all if it has fixed the issue but if it don't ill be back with more questions and hopefully get more answer

 

The only reason you need a scanner to do KOKO on OBD2 trucks is to clear trouble codes before doing KOKO. You said you already have a basic scanner so you are good to go.
Dont need to read TDC. Just get it to temp. Clear codes. Do KOKO. Easy.
OBD1 6.5s require a Tech 2 or software.
The CPS is part of the front engine cover. Sometimes when replacing they don"t go in exactly the way the old one was installed. So the KOKO will get the PCM to re-learn the new CPS.
You dont have to do the relearn. If you get CPS installed and it starts and runs good. No worrys.
But if you have issues, hard starting, rough running, ect. Then do the KOKO.

 

I keep getting the two codes p0251 injection pump rotor / cam system and p0370 timing reference high resolution system I ran the truck 170 plus and then cleared all codes and did the koko system still not starting unless I hold the pedal to wide open throttle and then it will run if I let off it will due out but if I hold it for a little the revs will only make it to 1000 prm when still holding hit I will shoot to 2500 rpm and shold idle at 1000 still bucks and still smoke a blue tint smoke at this point idk what I did wrong but im am stressed out

 

Okay will be continue until next weekend.
I will start with that and if I find air in fuel then I should probably fix that and if I don’t then what could that lead to next because if I did the KoKo system wrong how could I tell and if I try to do it again could it mess up other things.. I wish I was able to bring it to someone like you guys that Been there and done that and fixed it right!! I am just super happy you guy’s Are taking your time to walk me through things
I just love these old trucks and the way they run and sound and just look overall the best truck from the 90s in the k3500 series (in my own opinion)

 

Beings you have a number of codes. All we can do is process of elimination. Got the P0335 cleared so on to P0251. Yes check for air in fuel as OK said. That is an important step. It is possible air in fuel to trigger P0251 because it involves bubbles in the optical sensor. Even if not the cause of 251. Air in fuel is a common problem and causes all kinds of running issues.
One more thing to check. Where the wires hook up to the Optical sensor on the top of the injection pump. You will see a black box in line with the wiring harness, That is a filter. It does go bad. Simply unplug the filter and wiring from the harness and plug the harness back in to the OS.
Removing the filter may fix your problem. You can run without the filter with no problems. Many just remove it for good.
Here is a pic of the filter

 

Hello I’m back again I do not have that in-line filter for the optical sensor I also checked all the prongs and the pins to make sure everything was being connected and I’ve been flushing out my diesel by the T valve and the truck seems to be running better and better the truck is idling right now with no issues but if I do pick it up the revs it will sound like it’s miss firing I think I got bad diesel and I think i am missing a ground strap!! Does anyone have all the location for the grounds in the engine bay. I wanna go over all my ground and see if I am missing any I did have the exhaust manifold taken out valve covers done and intake gaskets replaced

 

Grounds links and more can be found in the 6.5L FAQ page as mentioned above

Grounds-Grounds-Grounds The importance of good grounds.....

This is not completely 6.5 related but I think it's very relavent. We always hear the people in the know around here (gmctd in particular) talking about checking your grounds for almost every problem under the sun..... Q. "Yeah I got a slow leak in my passenger's side rear tire, what could...

www.dieselplace.com

 

 

I also have the P0251code on my 98 K2500 HD. Had the injection pump replaced. Drove about 4K miles then went to Walmart about 30 miles truck drive fine. Was idling while I was checking tranny fluid and dies. Now all it does is crank but won’t fire. Checked the T valve and fuel is coming out. PMD has been relocated but not replaced with IP. I’m not sure where to find the CPS

 

Also all 8 injectors were replaced at time of pump. And is the cam sensor and the crank sensor the same thing? I know the crank sensor is by the harmonic balancer. Not sure if the cam sensor for the P0251 code is the same thing or not

 

I just don’t understand I installed at LP and change the fuel filter and redid all my ground cleaned up
It runs but feels like no power it drives around and around the block and once hit a hill it struggles feels like it’s holding back turbo kicks on fine no problem but it makes a pop sound when in high revs or if I hold it down in idle it seems like it back firing
Oil has been changed did all new valves cover gasket and intake
Literally all I did different was filled up my tanks for once because I had the extra money I normally throw in like 20-30 $ because I’m not going that far I filled up for 75$ And bam the day after went up a big hill to grab coffee 25% grade drove down it fine and then got coffee and then at the top no throttle response I had nothing at the foot pedal once I drop down to maybe like 30 miles an hour 25 I gain throttle pedal again pulled over ran the codes wrote them all down cleared them start the truck up again and it was just hard to start struggling I replace the PMD and now I have a number nine resistor installed

SO I just don’t understand at this point I want someone to work on it it’s 29 degrees outside and I’m am struggling Here if I can find a shoo that can time it for me then it might have to be like that because I don’t have the scan tool that everything talks about I got a blue point one and y’all keep telling me it’s garbage so. I don’t know what codes could be what and I have noticed that on my wife’s BMW

 

I just don’t understand I installed at LP and change the fuel filter and redid all my ground cleaned up
It runs but feels like no power it drives around and around the block and once hit a hill it struggles feels like it’s holding back turbo kicks on fine no problem but it makes a pop sound when in high revs or if I hold it down in idle it seems like it back firing
Oil has been changed did all new valves cover gasket and intake
Literally all I did different was filled up my tanks for once because I had the extra money I normally throw in like 20-30 $ because I’m not going that far I filled up for 75$ And bam the day after went up a big hill to grab coffee 25% grade drove down it fine and then got coffee and then at the top no throttle response I had nothing at the foot pedal once I drop down to maybe like 30 miles an hour 25 I gain throttle pedal again pulled over ran the codes wrote them all down cleared them start the truck up again and it was just hard to start struggling I replace the PMD and now I have a number nine resistor installed

SO I just don’t understand at this point I want someone to work on it it’s 29 degrees outside and I’m am struggling Here if I can find a shoo that can time it for me then it might have to be like that because I don’t have the scan tool that everything talks about I got a blue point one and y’all keep telling me it’s garbage so. I don’t know what codes could be what and I have noticed that on my wife’s BMW

Posting those codes when you get them each time will help us..
You could be getting a fuel limp, it could be an electrical issue, etc.. those codes will help us to help you