Truck randomly died today. NEED HELP

[MontanaJack]

Hi guys, its been awhile. And thanks in advance for your help.

The truck has been running great. then all of the sudden, about a mile after leaving the house... it just shuts off. Doesnt sputter, or chug, or puff smoke or anything like that. it just turned off like i turned the key off or something. Batteries are good and the alternator is new. wont start again. turns over fine. even with the help of either it wont fire at all. again, acting like the key is off. I get a tow from the neighbor, and when we pull in my driveway i smell something burning. I pop the hood, a wire on top of the IP is smoking and hotter than hell (after messing with it, the connection was loose and must have shorted). I cant remember if the key was in the on position or not. Now when I turn the key to the on position... nothing. I have to turn it to the start position for any lights, gauges, radio, etc. Keep in mind this truck has the push button bypass for the GPs. also, when the PO installed that, he also installed a push button for the starter as well. so normally this truck had accessory/off/on/blank with push button start and push button GPs.

I dont even know where to start. Im not much of a wiring specialist but I feel like I should start testing the ignition switch. I have no diagram though and wouldnt really know what Im looking for.

Sooooo..... What do ya think?

 

[crash-harris]

Trace that wire for the FSS. Sounds like it shorted out somewhere. May have fried your FSS in the IP and probably popped a fusible link (passenger side fender). Check all your other fuses under the dash just to be sure.

 

[Shadetreemechanic]

Trace that wire for the FSS. Sounds like it shorted out somewhere. May have fried your FSS in the IP and probably popped a fusible link (passenger side fender). Check all your other fuses under the dash just to be sure.

What he said. The original problem may very well be in the switch, but somthing in the frying of the FSS has probably now burned up a fusable link. Look behind the battery on the passenger side for a burned link.

 

[MontanaJack]

Thanks guys, I'll check them tomorrow. Like I said, I'm no wiring expert, so correct me if I'm wrong. Fusible links just look like really fat sections of wire because of their insulation right? Will I automatically know if they're burned up or do I just cut em all out and start new? And are they supposed to be pretty close to the relay solenoid behind the PS battery?

Thanks again, you're all a big help

 

[crash-harris]

And I forgot to mention, they are inline with the 3 yellow power wires that connect to the fender mounted relay.

 

[MTKirk]

You could also run a temporary hot wire from the battery to the Injection pump FSS valve (preferably with an inline fuse) just to see if it will run. This will help you rule out the FSS as the source of your short, and get you running temporarily.

Greetings fro Billings!

 

[MontanaJack]

Well I couldn't find any fried fusible links at the starter relay. But i found a sweet spot in the ignition that allows me to hold power to a few things. After about ten seconds of doing that, the FSS wire started smoking again and the top of the IP (the FSS I assume) was pretty hot to the touch.

I'm gonna guess the shut off solenoid is toast. Is that a replaceable part or do I need a whole new IP?

I realize I do have other issues that warrant attention as well, such as the ignition switch, but I'd like an idea as to the scope of this project.

 

[MontanaJack]

I took your advice MTKirk. FSS doesn't click. Fun fact though... when I hook up the jumper from battery positive to FSS post, the cab "dings" like the key was left on, but the key isn't even in the truck.

 

[MTKirk]

I took your advice MTKirk. FSS doesn't click. Fun fact though... when I hook up the jumper from battery positive to FSS post, the cab "dings" like the key was left on, but the key isn't even in the truck.

The ding is normal, you're energizing the same circuit, just from another location.

 

[MTKirk]

The FSS is replaceable, but if it was me and I had a '91 with the original pump, I'd just replace the pump. When you get done, run it to Billings & you can use my Ferret adapter to time it.

 

[MontanaJack]

The PO had a new IP installed about 10K ago. New, not reman. So I'm really hoping to avoid a new pump if it's not necessary. I found some Replacement FSS for $60 from Accurate Diesel, does that sound about right?

 

[icanfixall]

Acurate Diesel price sounds fine. You might check any fuel injection pump repair shop near you for this solenoid too. Be careful when installing the cover to the injection pump. If the latch for this solenoid is not correctly installed you have an instant full throttle run away and the pump governor can't control the engine rpm. they will not shut down by removing the power to this shut off solenoid either. Only cutting off the fuel or the air to the engine kills them. Best to have a piece of plywood large enough to cover the intake hole where the filter sits. A couple of rags will help under the wood because of the center bolt connection that holds the screen in place. Some have found if you run a hot jumper wire to this solenoid from the battery you can open the solenoid and allow it to be correctly placed back in the injection pump location. I have to tried this but am told it works. Please confirm before trying this. A diesel run away is really a scarey thing too. Look on u tube to see what they look like.

 

[MTKirk]

If you've got a new pump & the solenoid went out already, you likely have electrical issues that you need to address. If you have a switch that keeps the FSS wire hot while the truck is not running, that could shorten the life of the solenoid considerably- diesel flowing through the valve has a cooling effect, if the switch stays on too long without fresh cool fuel flowing by the electrics could overheat. Fix your electrical problems before you start running the new FSS, or you will likely be replacing it again.

If you have any rubber hose in your fuel system, you can usually stop a run away by clamping the fuel line with one of these http://www.harborfreight.com/radiator-hose-pinch-off-pliers-99704.html. After the lift pump works faster, but anywhere on the supply side will get it done.

 

[riotwarrior]

CO2 fire extinguisher sprayed directly into intake works too.

DO NOT USE DRY CHEMICAL

CO2 ONLY

 

[towcat]

Well I couldn't find any fried fusible links at the starter relay. But i found a sweet spot in the ignition that allows me to hold power to a few things. After about ten seconds of doing that, the FSS wire started smoking again and the top of the IP (the FSS I assume) was pretty hot to the touch.

I'm gonna guess the shut off solenoid is toast. Is that a replaceable part or do I need a whole new IP?

I realize I do have other issues that warrant attention as well, such as the ignition switch, but I'd like an idea as to the scope of this project.

two things.
one. change out your ignition slider switch on the lower part of the column immeadiately. your truck is one or two turns of the key away from burning to the ground.
two. your fuel shutoff solenoid needs to be replaced ASAP. if you are not familiar with the job, find someone who is. done improperly will result in a runaway motor.
good luck.