No Idea What To Do Next...HELP!

[Dragon5126]

This might be lengthy so bear with me. I'm at a loss so need some advice.

I've got a 77 CJ7 with a 304. My steering box went bad so bought a replacement. I also wanted to pull my engine to paint it AMC blue. I didn't have the means to pull the engine so I found a guy to do it. Now, it was running fine at this point. No issues...only the steering box problem. Well, after 6 months of my Jeep hanging out at his garage without an engine in it, I literally had to pressure him to put it back together...this is where everything started going bad.

I got the Jeep back to the house and it wasn't running good at all. This was about the time when I found myself going through a divorce so I didn't crank it for about a year. When I was able to get it from the house, it wouldn't crank at all. I don't have a good place to work on it at my new residence (divorce sucks in more ways than one) so I found a mechanic to work on it. What I've found is a lot of people don't know how to work on conventional engines anymore. Anyway, this is what has been replaced on this Jeep:

• Plugs
• Wires
• Distributor along with cap and rotor
• Starter
• Ignition module
• Carb cleaned
• Couple years ago, electric fuel pump was put on

Now, I'm guessing the plug wires are connected correctly and the timing is properly set. The problem now is what sounds like a misfiring but the major problem is the carb loading up with fuel. If it sits and idles, it will load up and die. At speed, there's a lack of power. I've checked the float..its not stuck. I don't know what to do with it. If the timing was off, would it cause excess fuel in the carb? btw...I asked the mechanic if the fuel pressure was about 4-5 lbs? He said the pressure is fine but I quote him..."something else is wrong with it."

Unbelievable. Any ideas? Thanks in advance!

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This is where the old engineering adage of the KISS PRINCIPLE comes in. (keep it simple stupid) return as much of it to original as you can and start from scratch. this means pull the cap and cables make sure the cap and rotor are good, reinstall, check the plugs and cables and make sure they are installed in the correct orientation, reinstall a Mechanical fuel pump and go from there
your fuel issue needs to be dealt with first or you cant be sure about the rough running. a mechanical pump will eliminate the possibility of fuel pressure regulator issues and the electric pump causing problems. (don't forget to change your fuel filter) if/when this corrects the fuel delivery problems look to ignition issues for rough running. if it doesn't correct fuel delivery issues look to rebuilding the carb as improper cleaning (removal and reinstall as well as reassembly) can create issues as well. but ALWAYS chase just ONE ghost at a time until it is logically eliminated or you will just be chasing your tail. Since fuel delivery is the most obvious issue right off this is the place to start, and an engine on the edge of flooding will run bad, so eliminate fuel issues first.

 

[Dragon5126]

fuel pump isn't manual, it is electric. I suspect this is part of the issue, the regulator isn't working. I suggest he goes back to the mechanical pump for the time being, get everything working then deal with the electric pump later. with all the problems mechanical fuel pumps could have, they had the advantage of self regulating fuel pressure.

 

[Dragon5126]

never ever dispose of something unless it is proven bad, besides it always fun to pawn them off for a good April fools joke...

 

[Dragon5126]

there is an old saying in the engineering arena, KISS (Keep it simple stupid) sadly most automotive engineers don't know it, but it works wonderful in trouble shooting, and you have explained it well, follow a methodical approach. pick the most obvious problem and follow it to the end. sure you can take the simple things to eliminate, like plug wires, make sure they are tight and in correct position, not laying in bundles causing cross firing, the simple things that don't cost money to fix and are common causes of rough running. But we need to check those when the engine runs rough only on a startup such as this and rarely if it has been running good and suddenly acts up (for others not you) But in this case the big issue was the fuel supply issues, and that isn't affected by ignition (err at least in this year model all bets off on the ECM/PCM operate model years) issues. I miss the old days. The only advantage we gained is no caps and rotors or flooding on steep inclines due to fuel injection... is it worth it??? sometimes I wonder...

 

[Dragon5126]

A while back I was running my 360 hard on the freeway when I carbon fouled a plug to the point the gap was closed. Cleaned the carbon out and she persisted with an occasion spit through the carb once in a while. Had a popping idea, despite all of the work I've done on this old CJ, did I ever replace the fuel filter.....
In a word, no. It's running fine now. Although this is more of a lean issue it can do no harm.

Actually lean issues CAN do massive harm. a lean running engine can over heat the pistons which are just cast aluminum and cause them to melt and throw slag about in the cylinder, blowing the engine. Forged pistons being harder are not as prone to this but can be affected as well, Higher compression engines force more oxygen per a given amount of fuel into each cylinder into a smaller space, igniting with more heat and force, this is why they use forged pistons, and require higher octane fuel, the higher the octane the slower and resulting cooler burning it is. And before you reply, I have no doubt you already know this, and realize it is more of a degree of issue than anything, but there are a lot of "newbies" out there, who don't grasp the principles most of us cut our teeth on, back when increasing horse power was done by sweat and hard work, matching manifold ports and heads in what we knew as porting so the openings matched for unobstructed flow, and similar hard work instead of just paying for CNC machined parts. And someone has to give them a clue... God I miss the old days...

 

[Dragon5126]

Have you checked the fuel return line for kinks or obstruction?. If what you said is accurate that the float is not stuck, if the return line is obstructed , the weakest link is the float needle. The pressure will keep building up and load up the float bowl beyond its capacity. Firing order should be on the top of the intake manifold as reference so you can verify that the wires are in their respective positions on the cylinder. Timing is another thing to check but not relevant to the fuel overfilling the bowl.

Sent from my iPad using Jeepz

your quote is misquoted That wasn't Confucious, it was Nanook of the North's mother! Just ask Frank Zappa! (watchout where those huskies go, and dont you eat that yelllooow snooooowww!)

 

[69jeepcj]

Good to see you posting again Dragon..

 

[Dragon5126]

Thanks ! I'm itching to get out and do work on my jeeps but this weather just isn't cooperating and you know, its an addiction!

 

[Dragon5126]

Thanks Greg! Dang man...before I read your post, I was kinda thinking it might be vapor lock. While I was sitting on the side of the road today, I was looking at the fuel line....it runs directly under the header and it's not insulated. Well, after I realized it wasn't going to crank, my daughter came and picked me up. I went back to the Jeep about 3 hours later and it cranked up and ran like a dream. I'll check everything you mentioned but doesn't that sound like vapor lock? One thing I didn't replace was the coil. Any chance this could be the culprit? I don't know....just grasping at straws now!

In that fuel line, you may want to reroute it up the firewall and splice some braided in to bring it over to the carb, keeping it completely away from the header, I don't recall where the mechanical pump is mounted on the AMC block... so This MAY be an issue if you don't go back to an electric pump. Even insulated, in the heat of summer fuel can boil around the headers if you don't insulate them as well, and if you do a lot of mudding that can be very problematic, AND expensive.

Edit: Ok its high on the front of the engine next to the water pump, so its viable to run the fuel line up the firewall, and use rubber or braided across the top of the intake manifold to the pump and back to the carb, staying away from the heat of the pipes.