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Discussion Starter #1 (Edited by Moderator)
Greetings all,

So my truck was running a bit rough. Hard starts when it was hot, and sat for over an hour. It would have to crank a bunch but would fire up. I figured maybe fuel filter needed replacing. This past Sunday i started the truck no problem. Put it in gear and drove 2blocks, and the motor surged (high rpm) then cut out and died.

I got it to start, drove back, replaced fuel filter, and it ran fine for about 40-50 miles. I got in the truck this morning, and drove a block. It did the same thing, high rev, and died.

I have bleed the system, check all the connections. It starts up super easy, and nice. But once under a load it does the same thing. In park the throttle response is great revs up nice and even, but once down to idle rpm it will surge. Not in any consistent pattern. Some times fast, some time long n slow. Then it evens out, and seems fine.

So I'm hoping someone can shed light. I see no visible fuel leaks, no tell tale smells of fuel leak.

I noticed since replacing fuel filter the idle is higher that it was.

Help!

Thank you, and appreciate your help

Michael
 

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Discussion Starter #2
Fyi, I had a crack in my hard line from lift pump to Ip this past May. I replaced the lift pump when fixing cracked line.

The only thing I have not replaced in the fuel system in the past 10years is the fuel tank sending unit. I inspected the rubber lines to fuel take, and they are dry.

Thanks
 

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You have the original fuel filter? These have a tendency to leak air at the seals. I've also gotten crap fuel pumps out of the box.
 

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Discussion Starter #4
It's an aftermarket spin on Racor filter. It's dry all the around.

Yeah I've gotten bad lift pumps too. But it's not leaking or seems to be leaking.

Thanks for the reply
 

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Discussion Starter #5
Also I was out of town for a month, and when I returned the truck wouldn't start. I nearly drained the battery before it fired up roughly. But then it was fine. That was mid September
 

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Thnx Dually. Where is it located? But would it cause a surge(dieseling) under load then engine cut off.
It will look similar to this pic and should be located just aft of the downpipe.

If it is restricted you will get no start conditions, surging and lack of power symptoms
 

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Discussion Starter #12
After sitting over night. I let glow plugs cycle, turn ignition starts up flawlessly. Once in gear and gets going maybe half way through first gear 5-10 miles n hour it surges up then begins to cut out almost to a stall. I let of gas pedal it then jumps around and stalls, or levels off and tries to go back to normal idle. It takes a bit but then idles fine.

I just started after sitting for 30-40 minutes with ease,. No surging. Just chill. I can rev it in park and fine.

I'm totally at a loss. Ugh.

I appreciate you all...
 

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Cat? What do you mean? Explain? It doesn't have one. It's a diesel.
California emissions equipped vehicles will have them.
Catalytic Converter or Diesel Soot trap as it's sometimes called will plug up over time and you will have issues.
 

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Discussion Starter #15
Copy that. It's a dual exhaust, and nothing but mufflers at the very end of exhaust pipe. Then a few feet of pipe. I don't think this could be the issue. But appreciate your input. And I'll rule nothing out
 

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Copy that. It's a dual exhaust, and nothing but mufflers at the very end of exhaust pipe. Then a few feet of pipe. I don't think this could be the issue. But appreciate your input. And I'll rule nothing out
If you have not done so yet, I would install a piece of clear fuel line on the return side of the IP to help locate any air in fuel gremlins.
If you see any air bubbles within the clear line then you will need to hunt down the source of the air intrusion
 

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Discussion Starter #17
Ok so I started the truck again it surged and died. I took off air cleaner, and now there is a small puddle of fuel in the intake gully. It looks like there is fuel leaking out from under the IP.

I can't tell exactly where, but looks like from where it connects to the manifold.

Is there a gasket in-between or is it metal to metal. Or am I just ****ed. I replaced the IP 10yrs ago with probably a reman.


FML.
 

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I would pull the intake and see whats leaking, it could just be a fuel line or clamp.


As for thew surging and dieing, sounds like either sucking air or dead lift pump to me ...


:bigglasse
 

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Yea pull the intake and fire it up, just don't let any rags get close.


I am with the others on either air leak or bad lift pump.

Usually an air leak will just cause hard starting though and be ok for the rest of the day then once it sits overnight then it's hard to starting the next morning.


One area to check is the connections where the lines come out of the tank, they will develop little pin hole leaks.


Good test for your lift pump is to unhook the output side and see if it is pumping a good amount of fuel while you crank the engine over, disconnect power to the IP so it doesn't start.
 
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