# 06 Cummins surging when cold



## barbless (Jul 27, 2004)

after startup in the morning my 5.9 surges a little at idle but not above idle and not when the engine is warm at idle. It runs great but I'm concerned this cold surge is the precursor for something about to go out. Could it be the the fuel control accuator?


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## devil1824 (Sep 4, 2010)

When its REAL cold my 06 does it. Just guessing here but I would say below 40. Never in the summer time though.


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## barbless (Jul 27, 2004)

mine is surging now after sitting all night. Don't know what'd it do if it was really cold out.


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## reedkj (May 4, 2009)

just my .02 but you might have your injectors looked at... how many miles are on the truck? any mods?


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## JED (Nov 14, 2004)

There is a air intake "grid heater" that creates a surging at idle on cold starts. It takes the place of glow plugs on the 5.9 and helps the engine warm more quickly and controlled. Mine only kicks on when it's colder and not at all during the summer.
The sensor is on the plastic intake tube right down stream of your air filter, it may need cleaning or replacement.


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## barbless (Jul 27, 2004)

96K miles on truck. I know about the grid heater surge but the time between surges is very short and it shouldn't be coming on now. I bought a qt of Lucas fuel system cleaner so I'm hoping that takes care of the problem but i'm not holding my breath.


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## reedkj (May 4, 2009)

my father's truck started doing this around 185K miles, injectors were "leaking" . He would have to plug his truck in everynight so it would start in the morning. New injectors fixed the problem and the truck is still running hard at 260K miles


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## JED (Nov 14, 2004)

barbless said:


> 96K miles on truck. I know about the grid heater surge but the time between surges is very short and it shouldn't be coming on now. I bought a qt of Lucas fuel system cleaner so I'm hoping that takes care of the problem but i'm not holding my breath.


If your voltage isn't fluctuating during the surging then it's not the grid heater. I've heard of guys 'mainlining' injector cleaner they say it helps but I've never done it. They change the fuel filter and fill the reservoir with injector cleaner. Some will go through the injectors and most will get back to the tank. But it will put undiluted cleaner where it counts.


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## Knot Kidding (Jan 7, 2009)

barbless said:


> after startup in the morning my 5.9 surges a little at idle but not above idle and not when the engine is warm at idle. It runs great but I'm concerned this cold surge is the precursor for something about to go out. Could it be the the fuel control accuator?


This can cause a surge. Do you have any hesitations when taking off. Any check engine lights?


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## barbless (Jul 27, 2004)

KK, no hesitation and no engine lights. It stops surging if i just give it a little throttle above idle and runs fine down the road. When warm there is no surging at idle or at any RPM.


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