Engine/Transmission (1994 - 1998) Fuel solenoid problem?

[GJolicoeur]

My '97 3500 has been acting up lately on startup. I can turn it over, it fires right up and then dies when I let go of the key. If I hold the key in the start position for a couple of seconds after the engine starts, it'll keep running fine until I shut it down again.



After searching the forums, I'm confused as to what might be the problem. I was just going to get a new fuel solenoid since I've got 225,000 miles on the truck, but after looking at other people's symptoms, I'm not so sure that's the problem.



Any advice from the smart ones out there?

 

[Signal73]

Does it stay running if you hold down the throttle a little when you go to start it?

 

[GJolicoeur]

That's how I always start it. A little throttle, and it starts right away on the first piston up on compression. Then, as soon as I let go of the key and let it return to the run position, it dies.

If I hold onto the key in the start position for 2-3 seconds and then let go, it'll keep running.



It just started this yesterday. I noticed that I had to turn the key 3-4 times to get it to keep running, and then, this AM, it wouldn't keep going after any number of start attempts, until I tried hanging onto the key, and then letting go.

 

[GAmes]

Don't get a new solenoid, 225k is just barely broke in. Two bolts, a spring clip and a wire connector is all it takes to remove the solenoid. Pull the plunger out, clean it up with 1000 grit sandpaper, clean the bore with a shotgun brush and reinstall it. Takes 30 minutes at the most.

 

[Got Smoke?]

Sounds like you've got a problem with a connector @ the wiring harness for the FSS. Because one wire is 12V power, other wire is 12V hold up, 3rd is ground.



Also check the blue wire on the + battery terminal on driver side battery.

 

[CumminsPower98]

A bad relay on the firewall just above the fuel filter can also cause this.

 

[Got Smoke?]

A bad relay on the firewall just above the fuel filter can also cause this.

I started to say that, but I figured it might be the wiring harness because he said it wouldn't stay up.



For anyone needing it I have a "how to" with pictures in my readers rigs on how to disassemble your FSS relay and clean to contacts to check it before buying a new one.

 

[Howard Durand]

I agree with GAmes, remove the solenoid and clean it real good along with the electrical connectors. Also, check the condition of the rubber boot. It may have become damaged preventing free movement of the plunger.



Start position of the ignition switch energizes the pull up coil through the "Fuel Shutdown Relay" that is on the firewall. The pull up coil has the strongest pull which is needed to overcome the spring tension on the fuel linkage. If everything is clean and nothing is binding, it should snap into position as soon as the switch is turned to start. If the switch is held in the start position too long, it can destroy the coil.



The hold coil is fed from the PCM and remains energized as long as the ignition switch is on but it only has enough pull to hold the plunger in the run position.

Most likely the solenoid plunger is being pulled up far enough to provide fueling but not far enough for the holding coil to keep it up.



Electrical things usually work or they don't. Your trouble appears to be more mechanical.

 

[hsmith]

Hello stranger, I see you are about to get that truck broken in! I have only 165k on mine now. Runs better every day.

Smitty

 

[GJolicoeur]

Bingo. I pulled the relay apart (took 4 dinner knives pushed down the sides to slide it out without wrecking it). The contacts were only lightly corroded - no arcing or burning. I cleaned them up and put it back together and plugged it in - still starts but doesn't stay running.



I pulled the solenoid and found the problem. It's not corroded - amazingly, but the boot was ripped and falling apart. (The bolts are 5/16" if anyone is wondering). Some of the rubber had gotten curled into the spring and was not letting the plunger slide freely.



Sooo, I put it back into the truck and it starts and runs perfectly. Does anyone know where I can get a new boot?

 

[Joe G.]

http://www.fostertruck.com/dodge/default.htm

 

[GJolicoeur]

Wow! You guys are great! Thanks for the help - putting all these miles on these things is a lot better with the help. You were right on Howard! Thanks Joe for the link to LarryB.

 

[Howard Durand]

That is the beauty of these forums. Anytime someone has trouble and asks for help, there are usually a number of responses from folks who have experienced the problem or have some expertise on the subject. Quite often the problem is solved.

In this case, it could have been any one of several possibilities. The rubber boot is probably one of the less expensive parts but they are not easy to find unless you happen to know about LarryB.

 

[KYOUNG]

I used about 4 inches of bicycle tube on mine. Cost was nothing and a tie wrap... ...

 

[hsmith]

5/16 = 8mm. We interchange all the time.

 

[Got Smoke?]

I used about 4 inches of bicycle tube on mine. Cost was nothing and a tie wrap... ...

Tried this route before, but mine never stayed intact. Tube always slips off.

 

[Howard Durand]

I had the solenoid off when I replaced the governor springs. The rubber was cracking and splitting but had not come apart yet. I tried DC and Cummins both and they told me that it was not available as a separate part.

I painted the whole thing with liquid electrical tape and it has been working fine for a couple of years now. Think I'll get one from Larry and keep it handy.