75 CJ dyin goin uphill!

My 75 Cj5 has decided to be ornery and now cuts out or dies going up hill, on pavement, almost like it's starving for fuel. It starts right back up though and then runs rough a gain..It also sems to run better cold. I thought it was the fuel line running on top of the manfold getiing hot and vapor locking.. I replaced/re-routed and still persists.. Also installed a new fuel filter.. Any ideas as to where to look next??

304, with a 2BBl Holle carb, and factory Electronic ignition.

 

Holley! The Holleys are notorious for stalling at certain attitudes. Check the archives.

Re the fuel pump, see how much fuel it pumps - put the outlet into a jar and time how long it takes to fill. There's a spec... There's also a spec for pressure. Either that or just replace it - they aren't expensive, and if that isn't the problem, you'll have a spare.

 

Check float setting, when it gets in a angle if not set rite it will starve for fuel.

 

and the specs would be.......
volume test- one quart of fuel in 60 seconds or less, at 500 RPM
vacuum test- at least 10" of vac at 500 RPM with hose from pump to carb disconnected for max pump capacity
pressure test- 5 to 6.5 PSI at 500 RPM, with length of hose to press gauge not to exceed 6" in length

 

there is also a "sock" type mesh screen filter over the fuel pick up tube inside the fuel tank; the pickup tube is part of the sending unit; if all else fails, dropping the tank, removing the sender, and visually checking/replacing this filter might be an option.
NOTE: this filter is 2 3/4" long; if you choose to remove it, you shorten the overall length of the pick up tube; this means you will run out of gas sooner than the gauge indicates, as it cannot pick up near the bottom of the tank, FYI
of course, as with any Jeep, a PO may have already performed this task

 

...and if your vacuum test shows high pump readings, higher than what is listed, this could be the culprit as the pump is straining against the restricted filter

 

The pickup tube filter is available here: http://www.bjsoffroad.com/cartgenie/prodInfo.asp?pid=310&cid=5 ... This is for FSJs - I'd assume it's the same across the line.

Probably available from other suppliers too.

 

Could also be Timing, Would Break out a light and CHeck the timing First

 

I had the very same thing happen to me with a '71 a couple of years ago. I tried everything...the problem was one piece of fuel line had a small hole and was sucking in air. So, I suggest that you replace ALL the flexible fuel line.

 

On a 350 chevy I had similar problems, after much work, it turned out the pump casting was porous and under a load a stream of fuel would shoot out of the side of the pump and hit the exhaust!!!!! The hole wasn't visible with the naked eye. Probably one if a million, a buddy found it while I was revving the engine in the driveway.
Maybe replace the pump (fairly cheap) and keep the other as a spare if it is isn't the problem.

 

Thanx for all the help adn suggetions.. So far i have only made it worse! I opened up the Holley and replaced the Power Valve, and the associated gaskets.. Now, i am exremely rich and the garage stinks of gas. The wife aint too happy about the smell.. I'll continue this weekend and let ya know when I find the problem..

 

Ok, if you're interested I found out why my jeep ran too rich after I replaced the PV and the metering block gasket.. I went to the HOLLEY site and found in the tech section a note about the metering gaskets.. Seems there's 2 different ones.. The one I had is probly the wrong one allowing the vacuum to bypass the PV.. Thus the PV flows fuel all the time.. NAPA was closed this PM, so tomorrow I am going to try and get the correct part.. If it werks I'm back where I started originally..

 

Dont forget the filters, not just the one in the tank. It certainly sounds like fuel starvation.

 

Filters are next, but I pulled the fuel line and ran it into a can.. The pump was putting out plenty of fuel.. Afterwards the engine ran great for a minute , then started doin the hoochi koo.. I replaced the gasket with the proper one, but still it acts rich.. Black smoke etc.. , won't idle.. I'll keep looking.. Thanx for al the suggestions.

 

I had the same problem with my 1980 cj5 w/ carter 2 barrell. I was told to go with weber 2 barrell and that would stop my problem. It completly stopped it. I would definetly recommened going with the weber carb.

 

I had the same issue with my 72 CJ5 (4 BBL Holley) at French Lick this weekend (Jeep Jamboree). Just dying going up the inclines. Made for a terribly frustrating day (not even mentioning the shock i broke off...). Had to pack it in after only one day and headed back. I was hoping to find the silver bullet in this thread :?

Replaced my filter (a couple weeks ago) and pump is pushing through plenty of fuel.

 

Wel I finally got it repaired.. Of all things it had a load of water in the tank.. I drained the tank, and ended up replacing all the fuel lines, filter, etc.. Then installed new fresh fuel.. End of problem.. Thanx for replying..