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Chasing a Ghost

Cabledog

New Member
Messages
13
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0
Location
Princeton NC
Thread starter #1
Ok y'all I need some guidance here. I have looked and looked for a thread with my problem and have yet to find something close. I have a 1998 C3500 HD with the 6.5. It is hard to start when it's cold and I am talking about just the motor hasn't ran in a few hrs. It's only 70 degrees here at night right now. It spits and sputters and stalls. I have to start it about 8 times for it even to idle. When it does get to idle it does so like it has a big cam in it and lopes. I can leave it running for about 15-20 min until it gets to operating temperature and shut it off and restart it and runs perfect. Fuel pressure is good. Replaced the ignition and the harness to rule it out. And sometimes driving down the road it goes into a limp mode and won't go above 12-1300 rpm so I shut it off while driving down the road and restart and runs great. If anyone has had this problem please let me know or a solution ASAP. It's a bucket truck so it's keeping me from working right now. Thanks in advance
 

JayTheCPA

Well-Known Member
Messages
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993
Location
Annapolis, MD
#2
Welcome to TTS!

Any codes? FWIW, the PCM might set codes without triggering the SES light (yet).

For the grouchy cold starts, glow plugs seem like a possibility. Given the other symptoms, cannot rule out air and / or fuel delivery or electrical grounding. Although, given the comment about limp-mode effects going away after a restart brings the question about the PCM throwing codes again.

And, at what point was the fuel pressure checked?
 

Will L.

Well-Known Member
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Location
Boulder City Nv
#3
In the summer in Las Vegas, a 6.5 needs glowplugs.
ONLY AC Delco 60 G or Bosch 80034. avoid all others like the plague- they can destroy an engine.

checking fuel pressure after filter and before ip, right? 9-14 psi right?
 

Cabledog

New Member
Messages
13
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0
Location
Princeton NC
Thread starter #4
Thanks for the responses. I really appreciate it. Now yes I did check the fuel pressure and it is between 12-13 as far as the codes I can't remember off the top of my head exactly what they were but there was 2 and the one was about the timing for the IP. But the truck just shut off again after running 10 miles and idling for 30 min. Just sputtered and shut off. Started right back up with no issues. I know these motors were not meant for this type of abuse hauling around 15k lbs but I have to make it work for at least a month or 2
 

JayTheCPA

Well-Known Member
Messages
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993
Location
Annapolis, MD
#10
Knowing which codes will help lots toward focusing on a cure. Without them, it is more like shooting in the dark and not really knowing whether we are aiming toward the target or the neighbor's barn across the county. Just say-in . . . ;)

For getting the codes, consider a scanner versus one of the simple code-readers. Reasoning is that the code-readers only go so deep where a scanner can show what the ECM sees in real-time and pull historical (recent) codes that are no longer active.
 

Will L.

Well-Known Member
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Location
Boulder City Nv
#11
And this engine can handle the abuse well if you treat the heat issues and out the micro turbo for one more approximately sized for a v8.

Grab the codes and let us know.

The cps and ops work together to feed the evil komputer. Unplug one then start it. If it runs plug it back in and unplug the other. Start again. It will be harder to start but will start. If it doesn’t start while one is unplugged, it may mean the other component still plugged in is toast. DO NOT just buy one and install it. Let us know for proper diagnostic.

Cleaning all the grounds is never a bad idea and solves issue frequently. But understand you have to remove the wire, clean mounting area and the terminal, replace terminal if needed. All engine grounds, and both ends of battery cables.
 
Last edited:

1994ch

Active Member
Messages
458
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245
Location
South Carolina
#13
You could have two issues......something like a couple bad glowplugs or getting air in the system when shutdown causing the rough start.
Then a flaky PMD or CPS or Optic Sensor causing your loss of power / stalling.
 

1994ch

Active Member
Messages
458
Likes
245
Location
South Carolina
#14
Since it takes a while to clear out I would guess air in the system for the hard start.... have you tried putting clear hose on the fuel return line coming out of the IP to look for air bubbles?
 

Will L.

Well-Known Member
Messages
7,826
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6,859
Location
Boulder City Nv
#16
Go to any hardware store. 6” of 1/4 clear tubing. Look where it goes in video. This video is a horrible case of air in line. Truck was crazy hard to start and keep Running.
$3 for hose and 3 minutes to install. This is number one test GM calls for. Leave hose on permanently, will need replacing every few years but worth it for instant diagnostic any time there is any problem. All other fuel line should be sae30r9.


 

JayTheCPA

Well-Known Member
Messages
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993
Location
Annapolis, MD
#19
Cleared all the codes (it had 4 of them) ran it for and hour straight no issues. Then it died and threw the code P2051
P2051 looks like it is very rare for a 6.5. Might have to do with the injection pump.

What were the other codes? Did the P2051 repeat, or was it new?

Reason for the question is that the combination usually means something different than just the one.
 
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