Stranded.. Engine starts up then dies

[SmokingRocks]

I'm stranded in Buena Vista right now. Been dealing with this issue since about Denver. Problem was that my engine cut out on steep hills. I'd pull over and it would fire right back up.

Now I stopped at a gas station to take a leak and it won't stay running now. It starts up just fine and I can rev it but after 5 seconds it shuts off. I can rev the nuts off it and it stays running a bit longer but ultimately it dies again.

Not sure if it's a ***ed MAF or TPS or what. Help!

FIXED! 1/15 Maybe not actually 6/15
here is a overview of the whole issue and fix;

Day before, I went snow wheeling with a bud and had a great time. (This fact probably has bearing on this issue)

The next day I was leaving to head back home (5hr drive). I noticed several times that while cruising at 75 mph the engine cut out then came back quickly, all gauges normal and new oil so I thought nothing of it. Was climbing out of Denver on US 285 and the first major stall out occurred. Engine just cut out as if it lost fuel. Coasted off to the side of the road, checked everything; Oil - Fine, Coolant Temp - Fine everything seemed OK. So I cranked her over and she fired back up Oil Pressure - Fine, No Smoke out exhaust.

Continued to drive, this stall out happened several more times. Finally got into Fairplay (about two hours after first symptom). Thought it could be bad fuel as I got some cheap gas in Fort Collins (50 cents under anywhere else), so I put a half tank in of good gas. Went to fire the old girl up and she wouldn't stay running. Started up fine, idled fine for 5 seconds - exactly - then cut out. I finally was able to keep her going by holding revs for a bit. Got on the road and started praying that she wouldn't strand me in BFE.

Several stalls later I made it to Buena Vista, stopped to empty my tank, came back out and tried to restart her. This time the start - idle - stall thing happened for an hour. I got my tools out and started pulling sensors out, checking connections, looking for a ground out, twisting, prodding and inspecting every wire. Nothing seemed to work for me. Finally in a last ditch effort I started her up and shifted into reverse... she stayed running.... So I ran for the boarder still having 1.5 hrs to drive.

Got her home went inside and grabbed a drink.

For the next two days she sat in front of my house, not wanting to stay running, thinking the problem was finally persistent I grabbed a jump lead and was going to bypass the fuel pump relay (FPR) and resistor and hard power the pump. I was never able to do this because at that moment she decided to start working again. Pissed off I pulled out the FPR and pulled it apart, the contact looked like it was pretty fried.

So I ordered a new FPR and Resistor. Also I pulled apart EVERY connector I could reach from the engine bay and under the truck including the connector just forward of the left rear wheel (fuel pump power?). I sprayed them all with brake cleaner to displace water and remove dirt then blew them out with compressed air till dry and applied a ton of Dielectric grease. Put all the connectors back together and now I don't have the issue. Couldn't tell you which connector it was, I suspect it was the FPR connector as it had old dielectric grease and what seemed to be water in it but there were others that didn't look too good either.

I'm willing to bet that when I went snow wheeling I got snow into a connector and as it thawed it started causing issues.

Hope this helps someone else.

 

[blkprj80]

Possible fuel delivery issue? Maybe you got some s*** gas with water in it? I'd suggest a bottle or two of Heet. Assuming that stuff is still around.

 

[Mudder]

No sure about your engine, but the idle screw? I had an idle screw on an old engine screw its self in and out because the o ring was bad. Not sure if yours has one or not

 

[Jason hansen]

I had a fuel filter in my excursion clog on me rolling into flagstaff, it was cutting out on the hill coming into town from the north. Then in town it was running real bad, changed the fuel filter and put in a can of sea foam in the tank and that fixed it. In a combat situation you could poke a hole in your fuel filter.

 

[tag3]

Usually a 60 series guy but have read in the 80 series that a fuel pump relay sometimes goes out. Just a thought.

 

[BVCOTaco]

I would guess something fuel related like filter or pump issues.
If you need help with tools or something PM me, I live in BV.

 

[SUMMIT CRUISERS]

Sounds like a fuel restriction, either a clogged fuel filter or fuel pump sock is my guess. I wouldn't worry about adding a pint of Heat to your tank. You live in Colorado and if you don't know what kind of gas you are buying then it is more than likely E-10. One fill of E-10 and you will have about 2 gallons of Heat in your tank. If you did get a bad tank of water/fuel, the ethanol/water mixture will fall out to the bottom of your tank. You could quickly remove and reinstall the fuel tank plug to obtain a sample of what is on the bottom. If it is cloudy then your fuel has water in it. Just a few ideas...

 

[landtank]

fuel filter, fuel sock or Fuel pump relay

 

[SmokingRocks]

So I got home. Here is an interesting twist;

For an hour I tried to get her going, as stated she started up and would idle for 5 seconds then just click off, like a light switch. I found that I could rev it some and keep it alive a bit longer but to no avail. Also that was like a light switch too, all on or all off (made me think TPS).

The last thing I did was start it and immediately shift it into reverse, and it stayed running.... Got me and hr and a half back to my house...

So IDK where to start, I thought fuel originally as I got some cheep gas ($1.50/gal) in fort collins. The issue started as I was heading into the mountains outside of denver going south, eventually I made it to fairplay and filled the tank up again with some gas from Shell. This is when it gave me hell trying to start it, it took a while but eventually I got her running and made it to BV. Thats when it gave me the s***tier side of hell.

So IDK if its a switch or TPS, I still am gonna check the fuel pump and sock though.

 

[blkprj80]

Check the fuel pump relay circuit as someone else stated.
It has a resistor that runs at lower pressure and the relay runs the pump at full voltage when needed.

A buck fifty??? Sounds like a good deal (not). I mistakenly bought gas cheap at Murphy's. The tank vented for a week, making my shop smell like an animal died in there. Gawd what a bad smell. From gasoline??? Yep. Dunno why.

Glad you made it home. I'm interested to see what you find.

 

[Reelitchy]

Just a thought. You may have some crap in the bottom of your tank. The quick surge in reverse may have been enough to slosh it out of the way and got some good fuel back in the line. Just a thought

 

[jfz80]

Not sure if the culprit but fuel pump relay is in drivers side fender b/w inner and outer and in a access hole up by firewall. It runs at 12v at startup and WOT and 6v at other times. There is a jumper trick posted on mud (landtoy80 I believe, Kurt in co) but I thought that made it run 12v all the time and that seems to be when you experience problems. See if you can borrow one from a a local mudder to test. Best of luck and glad you made it home.

 

[SmokingRocks]

Thanks guys, I'm gonna look into the whole fuel system. I regret buying the cheap gas now, I knew better but was just lured in by the 'savings'. Goes to show that it was cheap for a reason.

I'm gonna keep her around town until I figure out what the cause is.

 

[blkprj80]

The fuel pump resistor is over by the cruise control module on the PS fender. It has a big heat sink on it.
Make sure it isn't / wasn't getting really hot, and the connection isn't melted. Unplug it to check for sure.

 

[jfz80]

Also I have experienced a clogged pre filter sock before (dog hair don't ask ) and it idled fine but would stumble and die when you tried to accel and increase fuel demand.

Not sure if it helps. Just some info that may point you in the right direction.

 

[SmokingRocks]

Not sure if the culprit but fuel pump relay is in drivers side fender b/w inner and outer and in a access hole up by firewall. It runs at 12v at startup and WOT and 6v at other times. There is a jumper trick posted on mud (landtoy80 I believe, Kurt in co) but I thought that made it run 12v all the time and that seems to be when you experience problems. See if you can borrow one from a a local mudder to test. Best of luck and glad you made it home.

This sounds like it might be the cause of my issue. Because it started up just fine (relay would be at 12v) and presumably when it dropped to 6volts is when it stalled. Then I could give it throttle but it would only rev up if I had the accelerator pushed all the way to WOT.

It ran good as gravy when it wasn't acting up, smooth as a top. Idled fine, rev'd fine pulled fine... just turned off from time to time.

 

[blkprj80]

This sounds like it might be the cause of my issue. Because it started up just fine (relay would be at 12v) and presumably when it dropped to 6volts is when it stalled. Then I could give it throttle but it would only rev up if I had the accelerator pushed all the way to WOT.

It ran good as gravy when it wasn't acting up, smooth as a top. Idled fine, rev'd fine pulled fine... just turned off from time to time.

Actually, that could be an indication your resistor is going bad. The relay was working as it shorts "around" the resistor, making it essentially a dead short across it, but only during start and WOT.
If your resistor, or the connections were bad, it would "starve" the fuel pump for power.
It could also be a weak fuel pump due to a clog or something, and it needs full power (relay closed) to pump enough fuel.

Your relay doesn't sound like it's the problem. It was doing it's job like it should IMHO.

Do you have an EWD (electrical wiring diagram) for your '93?

 

[SmokingRocks]

I've got the FSM for a 94' i need to crack it open and take a look at this system. Im just baffled as to why it was an issue when in park yet was OK when it was in gear...

 

[jfz80]

Jut go steal a bunch of parts off joeys truck and swap em over

Blkprj80 info above makes sense. Looking for jumper link anyways but MUD keeps erroring out

 

[SmokingRocks]

Also I should point out that originally the issue only showed up when I was pushing the engine pretty good to get up steep inclines, not sure if the added heat or increased fuel demand is the culprit here.