6.5 running rough and surging

[Joseph R]

Hey, so about a month ago my clutch rod broke on my clutch master cylinder on my 6.5. Long story short I didn't fix it right and it sat until I got it towed to a shop last week and the day I got it towed I went out and brushed the snow off and reconnected my batteries. and ever since I got the truck when I go to start it and I turn the key on there would be a pretty loud sound that I assumed was the glow plugs because it would come on when I turned the key and would go off when my glow plug light turned off. but when I went to reconnect my batteries I turned the key and my glow plug light came on like normal and went off after a normal amount of time but there was no loud sound with them but I could hear them click off when the light went away which concerned me so I didn't try starting it. but I looked it up and apparently glow plugs don't make a sound so I didn't really know what to think. and the shop got the clutch fixed and squared away but when they went to test drive it they said it was running rough and stumbling and I've kinda hit a brick wall because this is my first truck and I know nothing about diesels. after looking up if glow plugs make sound google said the sound I'm hearing is the "fuel injection control module" and when I looked that up for a 6.5 all that came up was PMD's so I'm thinking my PMD went out and I have another in my truck so tomorrow in going to the shop and gonna swap it out in the parking lot but I just wanted to know what the more knowledgeable people thought. could it actually be my PMD?

 

[Dave69]

The clicking you hear is the glow plug relay. I would be looking for air in the fuel lines for the cause of it running rough after it’s warmed up . If it does it when it’s cold then goes away as it warms up I would be looking at glow plugs.

 

[RLC2020]

check lift pump pressure too. A bad filter and a faulty lift pump would restrict fuel and that could be your issue. Open the fuel valve at the front of the engine and turn the key on, you should get a steady stream. The sound you are used to hearing is probably the lift pump running. without it the engine will be hard to start and could have running issues as well.

 

[Joseph R]

The clicking you hear is the glow plug relay. I would be looking for air in the fuel lines for the cause of it running rough after it’s warmed up . If it does it when it’s cold then goes away as it warms up I would be looking at glow plugs.

it's not a clicking sound, I don't know how to describe it I wish I could post videos here.

 

[fancyTBI]

it's not a clicking sound, I don't know how to describe it I wish I could post videos here.

Film the video then post it to YouTube. You can set the video as private so only people with the link can see it. Or maybe it will go viral and you’ll get some money.

 

[Joseph R]

Film the video then post it to YouTube. You can set the video as private so only people with the link can see it. Or maybe it will go viral and you’ll get some money.

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here’s a cold start video before it broke down, that sound comes on and goes off with my glow plug light and when I went to reconnect my batteries last week it made no sound

 

[Dave69]

Well, I’ve had a bunch of these trucks best thing I can think of is lift pump ,,, maybe a rotary pump? It’s noisy

 

[Joseph R]

Well, I’ve had a bunch of these trucks best thing I can think of is lift pump ,,, maybe a rotary pump? It’s noisy

It is very noisy isnt it.

 

[CumminsFever]

That is definitely a lift pump, and is not the factory gm "ticker" pump. It's failure to run could easily cause the running issues you're experiencing.
There is also another thing, sometimes, when you unhook the batteries, the computer will lose it's timing setting. This doesn't happen every time, nor on every vehicle. Just sometimes. Good ol' gm programming!
Get that lift pump running and see where you're at with the running issues.