Engine/Transmission (1994 - 1998) Hard Start Situation

[arollan]

It has been cold for a while here in NC so the truck has gone to bed plugged in for the most part. When it is plugged in it winds up facing uphill. It has been hard starting lately and I attributed it to the cold temps... however, since it has been warming up I no longer park it uphill to plug it in, it now sits facing downhill. Starts fine even down to 35 degrees. While sitting at work for 8+ hrs it has become hard to start. It acts as if fuel drains back to the tank.

That said, Larry B's fuel line kit was ordered and installed. Still has the same problem, maybe not as bad - hard to tell though. Once the truck is up and running short shutdowns dont affect it at all. Ordered an OEM lift pump and it will go in tonight or tomorrow, however, I have been reading a lot of things about the fuel heater going bad, bad steel lines, shutoff solenoid, etc. Any other ideas out there?

I have a hard time believing it is a fuel relay or shutoff solenoid since the truck acts normal once the initial startup has been overcome...

 

[ttbird]

Check the fuel heater, likes to leak air at the electrical connection on heater. Joe advises it's removal, I rebuilt mine with Cummins parts, if you check the search forum, you should be able to get the parts numbers from there. I did, awhile ago but can't find them now in my mess of papers that never get filed.

 

[Joe G.]

If anyone can show that the fuel heater is actually doing something useful I would advise rebuilding it too. As far as I can tell it is just a failure waiting to happen. Rebuild it and it will still fail eventually.

 

[Missouri Mule]

arollan, Fuel leaks, Bad lift pump and bad overflow valvel can produce the same symptoms. Since it is not constant the overflow probably can be ruled out.



You already took care one the most infamous leak problems ( fuel line hoses).

The lift pump check valves can go bad. If putting a new one on does not solve the probelm you will need to look for leaks in other places (fuel heater, o-ring leak at fuel water seperator valve, hose from heater to lift pump ... ).

 

[arollan]

Update

Update:

Installed lift pump... what a pain by the way!

Hard starting condition solved - at least the 24 hr test has worked out. It stumbled for a split second after work today, but not like before. That leads to the new problem - fuel leak. I beleive the truck has had this leak developing for a while now, what I initially thought was an oil leak, now I believe is a fuel leak.

The leak developes at the rear engine side of the injection pump. There is a small bracket that connects the pump's lower right corner to the block. The drip falls off that bolt head. I have looked and looked, all I can see is the actual drip, not where it originates from. From the feel of it, the entire lower part of the pump is wet, but hard to say for certain. The check valve sounds like it is working - when priming the filter you can hear it open and bleed off. Any gaskets in that region of the pump that tend to go bad? If so, does the pump have to be removed to replace gaskets? Time for a rebuild? (Hope not... ) Truck has 200,000 miles on it btw.

Thanks in advance - time to study the manual on injection pumps...

 

[arollan]

I've been doing some reading and I presume the swap to ULSD could be a culprit. I am beginning to think I need to get a seal kit for the IP... any advice for doing this rebuild? Any part numbers or prices?

 

[RottenRon]

I had a similar mystery fuel leak on the injection pump. I had a buddy work the accelerator while I looked at the pump with a bright light; found the leak was from the overflow valve washer between it and the pump. Replaced the washer and... still leaked. Took it apart again and saw that there was a slight gouge on the pump. I just sanded it smooth and put on yet another new washer... no more leak.



Got the sealing washers at the local Cummins repair shop. P/N is 3918192 Washer,Sealing $5. 19 each up here in Canada. Get two. Hope this helps.



Ron

 

[RottenRon]

The metal return line on mine also leaked behind the pump. They are no fun to change.

A few things that worked for me:

- had to file the head a bit to get clearence to remove the overflow valve

- there are two bolts holding the line on, one you can see if you look down from the overflow valve and the other is at the back of the pump

- I couldn't pull the metal return line out until I disconnected the oil feed line to the pump which is behind the pump. It was hard to disconnect and even harder to get back on when you're done



This job required a big pile of patience! If you find yours is leaking I'd recommend just getting a banjo bolt with a male fitting on it and running 5/16 marine fuel line from the overflow valve to the metal line by the transmission. Leave the old metal line there.



If yours is leaking and you want to replace it, the Fleetguard P/N for the metal return line is 3923171 Tube,Fuel Drain



Hope this helps.



Ron

 

[arollan]

Thanks Ron. I will look into those options.

The fuel leak drips from the right rear (motor side) of the afc housing. Seems to maybe be in the form of a drip from somewhere, running down the surface of the afc and dripping once it reaches the end of the casting. Don't know yet though. I figure ill get a good mirror assy from the store and get a good look in there. Dodge dealer today told me they can't get the banjo washers for some reason or another - I'll call back with pn's tomorrow and fuss at them.

Thanks for the help!

 

[arollan]

Ron, I looked today and the location of the leak is where the metal return line (the pain in the butt one to change) connects to the rubber line that runs who knows where, somewhere behind the fuel filter. Could this rubber line be subject to age or is the the actual steel line you are replacing? Where does the rubber line go?

 

[Joe G.]

The rubber line goes to the steel line that goes to the tank. The rubber line fails many times by leaking from the end.

 

[arollan]

I replaced the rubber line yesterday, not too difficult. However, still leaks. Can the steel feeder line to the rubber hose go bad? Leak is still in the general vacinity of the steel to rubber connection close to the AFC housing...

 

[RottenRon]

Yes, the steel line can go bad. Mine did. Did you check the overflow valve banjo bolt washers yet? I'm glad to see you changed the rubber hose, did you find that the old one was cracked and generally ready to fall apart?



By the way, leaks in this area drove me nuts for a couple of weeks. I ended up changing the metal line, the rubber line that you just changed out, and the banjo bolt washers. I did fix the leak.



Ron

 

[arollan]

Yes the rubber line was cracked internally and deformed by the clamps pretty badly. Nothing hurts by replacing it - what's $1. 50 worth of rubber hose? I got the steel line today from the dealer, which was a pain for them to find on their computer. I will install it tonight or tomorrow, weather and wife permitting Banjo bolt washers are in at the other dealer, will get them tomorrow.

Thanks for all the great help guys - it's good to know all this info is here when you need it the most!

 

[arollan]

Replaced the steel line last night in about an hour and a half. Got used to laying across the radiator and reaching my arm full length around the injection pump, so getting to the rubber return hose and the rear most steel line mount was not too bad. The front banjo was a bit tight but had no clearance problems by taking out the spring retaining bolt in the top of the banjo. The middle mount bolt was the hard one... had to go to the store to get a socket u-joint and some extra extensions, removed the air intake horn and my manifold pressure hardware (just in case the wrench got wild) and with a mighty crack, everything was loose. Getting the line out requires the removal of the oil line supply to the IP, simple enough with the intake horn off. Getting the steel line in and out requires a degree in Geometry too. Took the old line out and began doubting it was the problem of my leak. Wiped it down and gave it the air test and sure enough you could hear air leaking from somewhere. Bent the line slightly and found a MONSTER spiral crack developed around the middle mount. So my leak would leak at the mount and propagate downhill back to the rear mount and then drip. Installed new line and the rest of the components I removed, washed the motor, and let it run for a bit - no leak so far, but that was in the dark at 9pm last night. The real test will be to see if it held fuel prime overnight. Thank you all for the good advice, what started as a frame rail fuel line replacement turned into fuel lines, lift pump, checking fuel heater unit, rubber return line, and steel return line. At least I have a new fuel system minus the IP Keep up the good posts! Thanks for helping me narrow in on the steel line Ron, probably wouldnt have thought to change it until much later without your post.

 

[RottenRon]

I'm very very happy to have helped! I've taken a lot more than I've given from TDR over the last 3 years, it's nice to know I actually helped someone. Glad you found your leak. Post again or send me a PM when you're satisfied that's it's not leaking anymore, I'd love to hear the final outcome.



Ron