Engine/Transmission (1998.5 - 2002) engine is surging when cold

[Kf6cmp]

Hi all. I don't know if surge is the propper term or not but when my engine is cold, sits overnight when cold out, i. e. 40 degrees or so. , the engine starts up as usual then it drops rpm by 500 or so and go's up to normal rpm's and back and forth untill it die's. Then it cranck's with out starting. I don't continues crank ,to not overheat the starter, and after a few tries at starting, it starts and runs fine all day untill the next morning. I was going to clean airfilter and fuel filter, both are over due. There in not a code being throne either. I have aftermarket lift pump that is at around 15 pressure. I replaced the vp around 4 years back. any one have an clue to the problome?

 

[BGlidewell]

run some additive like opti-lube and see if that helps.

 

[RonaldLarson]

Had the same issue last week. Looked at my fuel pressure: Zero! It wouls run rough, surge and die. Dumped in spome Howes, sat overnight, Voila! No problems. Our temps were in the teens.

 

[BGlidewell]

Had the same issue last week. Looked at my fuel pressure: Zero! It wouls run rough, surge and die. Dumped in spome Howes, sat overnight, Voila! No problems. Our temps were in the teens.

I hope its not that cold in San Diego

 

[DavidC]

I will take a shot at this. The fluctuating RPM is the grid heaters cycling but the fuel canister also has a heater. Could be no heat at the canister or air in the fuel line. Do you have a fuel pressure gauge ?. Fuel could be siphoning back to the tank and once you use up the canister volume it dies until you cycle the ignition switch to get enough fuel to restart.

Dave

 

[Kf6cmp]

Ok. I found a air leak in the air intake. AEF gromet on the air filter sensor. repaired and retried engine. not the problem. I found a fuel leak on the top of the fuel filter housing where the fuel heater wires go in. I know that there is an o-ring on this and will replace it. Has anyone had this issue? I figure there must be air being introduced into fuel system and thus making it hard to start. Does this sound right?

 

[DavidC]

Sounds right to me. Either way the fuel system needs to be air tight before you can move on.

Dave

 

[Kf6cmp]

hey what would happen if the fuel heater didnt work. what are the symptoms be ?

 

[DavidC]

From Service manual
FUEL HEATER
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation. The fuel
heater assembly is located in the top of the fuel filter
housing (Fig. 3).
The heater/element assembly is equipped with a
temperature sensor (thermostat) that senses fuel
temperature. This sensor is attached to the fuel heater/
element assembly (Fig. 4) (bottom view). When the
temperature is below 45 plus/minus 8 degrees F, the sensor
allows current to flow to the heater element warming
the fuel. When the temperature is above 75 plus/minus 8
degrees F, the sensor stops current flow to the heater
element.
Battery voltage to operate the fuel heater element
is supplied from the ignition switch and through the
fuel heater relay. Also refer to Fuel Heater Relay.
The fuel heater element and fuel heater relay
are not computer controlled.
The heater element operates on 12 volts, 300 watts
at 0 degrees F.

Dave

 

[DavidC]

Heater Relay
FUEL HEATER RELAY
Battery voltage to operate the fuel heater element
is supplied from the ignition switch through the fuel
heater relay. The fuel heater element and fuel
heater relay are not computer controlled.
The fuel heater relay is located in Power Distribution
Center (PDC) (Fig. 5). Refer to label on inside of
PDC cover for relay location.

Dave

 

[Kf6cmp]

well the o-ring i bought didn't stop the leak. I now am looking all over for the propper o-ring. Dang , darn frustrating!!! I guess it has to be juuuust right. Thanks for all the help so far. P. S. it has been cold for San Diego. I know , sounds trivial, but cold hear is anything below 40.

 

[Kf6cmp]

O'Reillys Schucks
PN 64016
Width: 1/16"
Inner Diameter: 5/8"
Outer Diameter: 3/4 this is the o-ring that supposedly works, according to diesel trucks resource forum. I had to order them. monday we shall see.

 

[Corriher]

Geno's makes a replacement fuel filter kit number FFK9799 that does away with the heater and changes it to a spin on filter. I put one on about 2 years ago and it works great. No fuel problems here in NC and sometimes it gets has low has 15 degrees and even colder in the mountains when we go sking. 1999 3500

 

[RonaldLarson]

I buy all my dispoasables from Geno's. Great outfit.
I'm going to look up that kit. Sounds like a good idea.

 

[Kf6cmp]

still waiting for the o-ring from O'Reilly's. if this doesnt work then I'll switch to the one from Geno's.

 

[Joe Mc]

Check the metal supply and fuel lines on top of the tank. One of mine had a rusty spot and a pin hole, it would lose prime overnight and do same as yours is now. Prime time to install the vulcan draw straw - see Geno's catalog or on-line.

 

[Kf6cmp]

I installed the o-ring and put a bit of silicone seal for extra seal. installed the housing in truck and after cranking for awhile to purge air,truck started up with out a leak. I believe problome solved. I still have to wait overnight to see if it starts normally to be sure problome is completly solved. Thanks for all the replies and advice.