Fuel prob

[jdempsey]

Hey all, new poster here, and new to FSJs in general. I recently bought a '79 Wagoneer, to use for getting to and around a remote mountain property I bought up here in Western NC.

Engine purrs, starts right up no probs, got it home fine, even climbing the mountain up I-40 to Asheville from Hickory. Drove it around my house which is reasonably flat and a thousand or so feet below my other property. Never any probs.


A few days ago I pack up the dogs (Great Danes, I got the truck for them mostly) and the GF, and make the hour trip up to the mountain property, did fine, got about a mile away climbing a curvy hill, and it starts losing fuel pressure, and stalling on me. Luckily, a friendly neighbor with a tractor pushed me up far enough to get it off the road. Didnt have time to diagnose so we got a ride out, I came back the next day, thinking maybe this vapor lock thing I'd heard of was the problem, and that it would start right up. It didn't but once I got to inspecting under the hood, I notice the throttle cable sheath was broken, and turned out to be binding. Removed the broken parts, pumped the peddle a few times and it fired right up. Was just me though, so I had to leave the truck.


Fast fowarding to today, I go up with my cousin to pick up the truck, and decide to go on up to the property. Truck fires right up, no probs and runs great.

Property is up about a half mile of two-track that's pretty rough though. It crawls up fine in 2wd though, and I get about 3/4 the way there where there's a big incline and the trail gets rougher, I decide to put it in 4wd. I stop on an incline, then notice someone coming down in a 4-wheeler. I had to back up to let them past, and end up having a 10 min conversation with them, during which time I turn the engine off.

Once they leave, I try to start her up, nada. I'm on less of an incline at this point, but still pointed up hill. We pull the intake off, start poking around the carb, etc.. Can't seem to get any response, she tries to crank, but she's not getting fuel.

There's a clear inline fuel filter before a regular type fuel filter that I usually see gas in also, and it's dry. No pressure from the hoses that I can tell, no gas getting to the carb either, which is a ford carb the previous owners put on who were mechanics (not sure if that's a good or bad thing).



So, after that extremely long winded story, what should I be looking at first here?

I'm not a mechanic, although I am a decent machinist and restore old machinery, so if someone can explain it, I should be able to figure it out.


No experience with Jeeps at all previous to this, I was looking for a Bronco, when I tested a Wagoneer and fell in love. Guessing I'm going to have to learn more about working on vehicles, but I need to make this girl reliable.


Any help appreciate, and thanks in advance!

[Lord_Ov_The_Deep]

Well I had a sorta similar issue, a previous owner installed the OEM style fuel filter before the fuel pump on the frame. It's a metal filter with a single input and 2 outputs coming off. One line goes to the carb and one returns fuel to the tank. Check along the frame and anywhere on the fuel line before the pump. The return line was sucking air since it was before the pump (can't return fuel if nothing is pushing it). Quick and easy to spot!

Also sounds like it could be your float out of adjustment, incline causing your bowl to run dry with misadjusted float. Also maybe too steep of an incline for your carb. I have a holley 2bbl that dosnt like steep hills/will stall out, I hate it! Of course also make sure your fuel pump is indeed working. Pull the fuel line from the carb and run it into a tall cup or bottle, have someone with you and as always safety first (extinguisher/water). Empty cup? Then start tracing your problem, pull the line before the fuel pump and see if you have fuel. You may need to siphon or suck it out with something(turkey bastor!). Keep tracing back till you get fuel. May be anything from bad pump, clogged line, clogged filter or clogged pickup in the tank. Ive always been told by my auto instructor "K.I.S.S... Keep it stupid simple... Or keep it simple, stupid"

S.S.C.C = Symptom, System, Cause, Correction

[mokurt]

I had No pressure from the hoses that I can tell, no gas getting to the carb either,

With that info,I would check the fuel line from filter to tank.Check the fuel pump and the fuel tank sending unit/pick up tube.

[jdempsey]

Awesome guys, thanks for the replies.


That's what I'm leaning toward.. Will prob take a new pump out there with me, and research how to get at the pickup in the tank and the filter sock.

[Carnuck]

If there is no inline filter before the pump, check the fuel sock in the tank. If it's mushy, replace it or leave it off and add an inline filter right before the pump. I had issues with crud from the sock jamming the fuel pump inlet valve open. I was able to clear mine with a low pressure blast of air and chunks of sand and rust came out too.

[jdempsey]

Yeah there is one in front of it, clear body where i can see some filth, but typically there's also fuel visible, which isn't currently the case.


That's what's got me concerned about the pump, but it didn't look old.

[Carnuck]

Not in front of the carb. Down on the frame before the fuel pump. The other option is your fuel sender may not work and you have nothing in the tank.

[jdempsey]

Yeah there's one on both sides of the fuel pump. The one before it is clear bodied, which is was I was saying about not seeing fuel in it.


I'm *reasonably* certain that there's gas in the tank. Although I'll def take some out there with me just in case.

[babywag]

The pickup sock in the tank is probably gone, leaving the bottom ~1/4 tank unavailable to the pickup tube.
If the truck is @ an angle even less fuel becomes available under certain conditions.

When I started working on my dad's '79 the fuel pickup was in bad shape(rusty) and missing the sock.
The rubber fuel hoses were also original and in very poor shape.
Looked like this...

[jdempsey]

Yeah that makes sense, I know the previous owner had the tank off, and it doesn't seem unlikely the took the sock out.


I had about 1/2 a tank, I've seen the truck run with less than a 1/4, and the gauge works, but I was on a pretty steep incline.


I did however move it (a harrowing trip in reverse down a 1/4+ mi very steep bumpy 2-track with no power brakes) to a semi-level spot, and still wasn't getting any fuel.


If the pump runs dry, is there some priming procedure involved in getting it sucking fuel again?

[babywag]

little gas down the carb, sometimes the pump isn't strong enough to re-prime itself.

Could just be a bad/weak pump it happens.
They're cheap and only take ~15-20 minutes to replace.

[jdempsey]

Awesome, thanks so much for the help everyone.


Meant to get up there yesterday or today to try and fix it, but I"m dealing with an ear infection and a tooth that needs a root canal, so it may be a couple days.

I'll report back once I get a chance.

[jdempsey]

Hey guys, just wanted to update, and say thanks again.

I got up to the wagon today, took a few tries, but pouring gas in the carb, eventually got the fuel flowing.


I put 5 more gallons in her, and drove on up to the top of the mountain no prob. I think it was just the idling at incline.


I'm going to guess that the aforementioned issue of having the filter sock removed from the fuel pickup is likely the case.


If so, will this: http://www.teamgrandwagoneer.com/fue...-gw-1970-1979/ contain what I need to reduce the possibility of this same situation arising in the future?

[dkmcgowan]

If you were low on fuel, the last quarter, and on a incline, you might just need to take it apart and replace the sock. It might have fallen off, which helps it suck in the last part of the tank...

Since it's not your DD, I would just run it until its super low, drain it, drop the tank, pull it out, and see what it looks like... You might just need a generic sock on the end from the parts store.

It also partially still at times sounded like the float on your carb, you can pop the top off the carb and check the float while it's still on. Get a small measuring stick and check the height.

[babywag]

Hey guys, just wanted to update, and say thanks again.

I got up to the wagon today, took a few tries, but pouring gas in the carb, eventually got the fuel flowing.


I put 5 more gallons in her, and drove on up to the top of the mountain no prob. I think it was just the idling at incline.


I'm going to guess that the aforementioned issue of having the filter sock removed from the fuel pickup is likely the case.


If so, will this: http://www.teamgrandwagoneer.com/fue...-gw-1970-1979/ contain what I need to reduce the possibility of this same situation arising in the future?

I would just pull the old one(clean it up if needed) and replace the pickup sock.