Fuel issues

[82CJ7JEEP]

Hello All,
I have a 1982 CJ7 with an AMC 360, carbeurated engine, new mechanical fuel pump, fuel lines (pump to carb), fuel filter. I have a new 500cfm 2 barrel Holley carbeurator which has been set as well as I can. After driving for 4 or 5 ( after motor is at running temp) miles the motor will just act like it is either loading up or starving for fuel. It generally will die and after coasting off the road I can pump the throttle a couple of times and it will start right back up and be good for another 4 or 5 miles. Any suggestions would be greatly appreciated.

 

[SteelHeadz]

Had this problem before with mine but i never really persued the root cause for the concern. Instead, i installed an Edelbrock regulated electric fuel pump and haven't had any issues since. I would check to see which one of the concern is evident first (Flooding or lack of fuel) and diagnose it from there.

 

[kc jones]

It seems to me like flooding would be more noticed at idle when extra fuel is not needed, not at highway speeds. It's possible there is trash in the fuel system pluging it up starving it for fuel until it stalls. When it stalls suction stops allowing the trash to settle until it runs long enough to plug it again. You might try putting an inline see through filter right before th carb and when it happens again look to see if the filter is sucked dry.
Just an idea.

 

[82CJ7JEEP]

Thank you for the input. I will look into both suggestions, will be wheeling tomorrow, should have several opportunities to look at it. Thank you again.

 

[bobcat481]

I agree with SteelHeadz, throw an electric fuel pump on it. I put one on the Willy's and left the mechanical one on the block. Primes with a turn of the key now without any prolonged cranking. Best money I spent on the thing I think. Also I figure if one goes out, the other will get me home (assuming I notice that the first one went out!). Make sure you get one that doesn't put out more than 7 p.s.i. or so or you'll bypass the needles valves in the carb, and flood it out.

 

[Turbogus]

When you replaced the carb and lines, did you install a new fuel filter? I know it's obvious but just thought I'd mention. Keep it cool!

 

[82CJ7JEEP]

Thank you all for the information, while out wheeling this past weekend the issue arose and my son and I found the issue. Turns out the PO ran an unprotected wire to the HEI it was about 2 " above the right exhaust manifold, as it got hot it would reduce the voltage to the distributor causing no spark. We field repaired it to re route it away from any hot spots and drove the hour and a half home with no issues. thanks again for all of your assistance.
Dave

 

[82CJ7JEEP]

Good morning all, Sorry to say but the ignition wire near the exhaust manifold did not cure the stalling problem. This weekend my wife and I were out heading to the woods and it did it again. After receiving my manual I did find what appears to be the "vapor line" which appears is supposed to go to a "charcoal canister" is bent over and zip tied to restrict flow and there is no charcoal canister. Is it possible this would cause the issue with the jeep running fine and then just stalling out of nowhere? There is no real consistency to the stalling now, sometimes I can run an hour and others make it a quarter mile. The only thing relatively consistent is that it is at 45 mph or better and RPM range of 2100 to 2400. Any help would be appreciated.

 

[SteelHeadz]

One way to tell if the vapor line is causing a vapor issue in the tank and preventing a proper fuel delivery is to open up the line and run the engine. See if that makes a difference. Verify that the issue is a fuel delivery issue rather than electrical. One of the things to look at is the float adjustment in the Carburator. Not enough fuel in the float bowl will starve the engine of fuel at high RPM's.

 

[82CJ7JEEP]

Steelheadz, Thank you. I will be looking at it this afternoon after work. Will post later on the results. Could this also be a "vapor lock" issue. I have not followed the exact fuel line path yet (this afternoon). The PO also has an electric fuel pump on the framerail passenger side, (very bad install). I will also be looking at making this a proper and safe install. Thanks again for all of the assistance, I am starting to understand the phrase "It's a Jeep thing, you wouldn't understand".

 

[82CJ7JEEP]

OK, Hopefully I am getting somewhere. Gentlemen take a look at the pic of the electric auxillary fuel pump, (not used, and will be removed tomorrow after a trip to get new fuel line). It is leaking/seeping. I have not driven the Jeep since Sat. The spot on the garage floor was approximately 2" sq. Would I be safe assuming if it can leak then it can also suck air into the lines possibly causing this problem?

 

[SteelHeadz]

It's never safe to have a fuel leak. All it's gonna take is a small spark then off it goes in a fire ball. Hey! That'll be cool, ghost rider in a jeep, lol. Anywho, it would be safe to assume that the leak has to do with the issue your having with the jeep. I'd say fix it then retest .

 

[kc jones]

If the "vapor line" is what the tank vents off of ,I could see where kinking it or plugging it would cause the engine to stall. Without a vent eventually fuel will stop flowing and I would imagine it would be pretty hard on the fuel pump. I would try unkinking the vapor line to see if that fixes it. It's simple and don't cost anything. If it works I would then look for a vapor canister. But that's just my opinion. Good luck.

 

[82CJ7JEEP]

Good morning all,
I have bypassed the fuel line to the electric pump, which has fixed the seepage issue. I drove the jeep around town last evening on any roads I could get to and maintain highway speeds. Nothing happened, I want to believe this fixed the issue but am not going to hold my breath. What I did find and need assistance on is this. On the drivers side rear there are 2 vent lines off the fuel tank, they go to some type of vent container with the fuel vapor vent line I found tie wrapped at the passenger side front. My questions are these:
1. How does this work? Is there a check valve/ball in this canister that activates if fuel is introduced (as in a hard right turn)?
2. What exactly is it called and can I get a replacement?
Thank you for all of the help so far, and I look forward to reading the responses.

 

[SteelHeadz]

The canister is made to filter out the vapor before it's released out in the atmosphere, no check valves. You can probabbly find one in a junk yard or retrofit one from a newer jeep. This vapor line also assist the fuel tank for pressure variations from atmospheric temperature and fuel tank level. On the driverside rear, behind the tail lamp is a valve that opens and closes at a predetermined pressure to assure a proper fuel delivery along with the vented fuel cap. Another solution is to find a vent used for the axles . It looks like a cap that goes on the end of the axle vent tube. Just make sure it's placed where water or other elements cannot reach it.