No Idea What To Do Next...HELP!

TennesseeCJ

TennesseeCJ

New member
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!

View attachment 20527
 

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.

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First thing I would do is check the timing, timing off will cause a lack of power, or if the timing is too early or late your not burning all the fuel or getting a complete compression stroke. Is the carb over flowing with fuel when it loads up and stalls, or is it just so rich that it stalls. You said the distributor was replaced, so good chance the timing is off. The miss firing could be caused by the timing. I suspect timing and carb adjustment is in order. I have one question, did you put fresh gas in it after it sat a year, or just use what was in it? gas may have went bad.
 
69jeepcj said:
First thing I would do is check the timing, timing off will cause a lack of power, or if the timing is too early or late your not burning all the fuel or getting a complete compression stroke. Is the carb over flowing with fuel when it loads up and stalls, or is it just so rich that it stalls. You said the distributor was replaced, so good chance the timing is off. The miss firing could be caused by the timing. I suspect timing and carb adjustment is in order. I have one question, did you put fresh gas in it after it sat a year, or just use what was in it? gas may have went bad.
Click to expand...

One thing I failed to mention is this carb is a newly rebuilt Motorcraft 2100 so it may need adjusting but I'm pretty sure it's not directly related to the carb. Someone might ask why I bought a rebuilt 2100. Well, like an idiot, I cracked the base off the original when I was tightening it up! There were just a few choice words spoken after that happened!

Anyway, yes...so much fuel is coming in and overflowing that there will be fuel collected in several "pockets" on the manifold. I'll check the timing to make sure it's set properly. Good point about the gas...I have put fresh gas in but I did not drain the old gas out. Could be part of the problem as well.

One more question...I have an aftermarket air cleaner on this 304. Did the vent from the oil cap originally go to the air cleaner? Where should I run this hose now? Currently there's no hose on it and it spews a little oil under throttle. I'm just assuming all the vacuum hoses are properly hooked up to? I would love to have a CJ expert look at this but it's hard to find nowadays.

Thanks for the help!
 

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.
 
With todays gasoline you may have a problem with separation . If fuel sits too long water and condensation drop to the bottom of the tank where the pickup is and you may be pulling a mix of water and fuel thats why its running crappy . You may have to drain tank .Anytime your vehicle sits you should add Stabil to the tank and drive a bit .It will protect the fuel in tank and the fuel system. Boaters have this problem a lot because they sit a lot unlike a car which is driven everyday . But anything thats sits for a lenght of time use Stabil
Paul
 
fuel over flowing out the carb is a HUGE indication the floats are sticking, or the float level is set too high. Mine has done this twice after a rebuild. Sometimes you can tap on the carb with a screwdriver handle and the float will come unstuck, other times you have to take it apart. Fuel pressure could be too high and pushing fuel past the needle and seats filling the float bowl and overflowing it. The motorcraft is actually a pretty good carb off road, pretty good on angles.
 

your plugs may be fouled out if you have been trying to drive it. I would get the float level set correctly, put in a new set of plugs and see how she does..
 
Just reread your post and seen you have replaced the plugs and say the float is not stuck. Something as simple as loosening a carb screw could free a stuck float. Only thing I can think of to over flow a carb is stuck float, weak needle and seat, too high fuel pressure.
 
Guys...first of all...THANK YOU for all the replies! Ok..so, I had a guy check the timing this morning. It was advanced really bad so we got the timing set. It would crank up fine no problems. I took it out for a drive...tank was about empty so filled it up with ethanol free gas and everything was good. Then I got stuck in a LOT of traffic on this little country road. Stop and go for about 15 mins. It was idling fine the whole time but when I finally got past the construction zone and put some throttle in to it, it died. I let it sit for 20-30 mins and it still wouldn't crank. I put some gas into the carb and got it to fire up. Started home running fine..got in more traffic and it did it again. Any ideas what would cause it to idle fine for a long period but die when throttle is applied?

Oh..one more thing. We noticed this morning that when we pulled the vacuum hose off to check the timing, there was no vacuum. Put a gauge on it and nothing. Maybe the vacuum port on the carb is clogged?
 

Read your last post with interest . Got a lot of good people contributing here too. God bless them. From how you describe the driveability problem I'm thinking it couldn't be vapor lock like what happened to me on an old jeep I had ( '78 jeep cherokee V8 360) . I'm thinking more of a bad fuel pump that loses pressure due to a not so good diaphram. Return vent line could be causing back up of pressure to the float bowl so that's good to check as suggested but suction pressure has me wondering if your losing pressure on demand when accelerating . It's probably worth checking since the idle dosen't need as much fuel,recovery as acceleration does and the float bowl may be running low under demand. Now that you mention it , if that vacuum advance vacuum line isn't pulling above idle before the centrifical advance kicks in , you can lose the spark needed but it's funny it ran well when you first took the jeep out. Well can't assume , got to check . I'd say it's a good start to check the fuel pressure to carburetor and the suction from the tank and any in line filters as well. Definately check the problem with the vacuum advance vacuum source. If you feel there is carbon built up on the throttle plate where the carb bolts to the intake , that will block off that port . Give a shot of carb cleaner spray ( watch your eyes , ask me how I know) to see if it clears it and shoots out the bottom to the intake.
 
greg92jeepxj said:
Read your last post with interest . Got a lot of good people contributing here too. God bless them. From how you describe the driveability problem I'm thinking it couldn't be vapor lock like what happened to me on an old jeep I had ( '78 jeep cherokee V8 360) . I'm thinking more of a bad fuel pump that loses pressure due to a not so good diaphram. Return vent line could be causing back up of pressure to the float bowl so that's good to check as suggested but suction pressure has me wondering if your losing pressure on demand when accelerating . It's probably worth checking since the idle dosen't need as much fuel,recovery as acceleration does and the float bowl may be running low under demand. Now that you mention it , if that vacuum advance vacuum line isn't pulling above idle before the centrifical advance kicks in , you can lose the spark needed but it's funny it ran well when you first took the jeep out. Well can't assume , got to check . I'd say it's a good start to check the fuel pressure to carburetor and the suction from the tank and any in line filters as well. Definately check the problem with the vacuum advance vacuum source. If you feel there is carbon built up on the throttle plate where the carb bolts to the intake , that will block off that port . Give a shot of carb cleaner spray ( watch your eyes , ask me how I know) to see if it clears it and shoots out the bottom to the intake.
Click to expand...

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!
 
Yes a coil could cause the stalling in traffic, but doesn't address the carb loading up.
The coil gets hot and loses its voltage output, I think they call it heat sink. had one go bad last summer, id be driving along fine then it would start to die as though I was running out of gas, (spit and sputter for a second, then die) after letting it sit for a few it would start back up until it decided to do it again. On the vac advance, there should be two ports on the carb (one ported vac, one full manifold vac) Ported is above the throttle plate and gives little to no vac at idle, but increases as the throttle is opened. Manifold vac port should be below the throttle plate and will give full vac at idle, but decreases as the throttle is opened. Most 70's and 80s cars used ported.
 
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69jeepcj said:
Yes a coil could cause the stalling in traffic, but doesn't address the carb loading up.
The coil gets hot and loses its voltage output, I think they call it heat sink. had one go bad last summer, id be driving along fine then it would start to die as though I was running out of gas, (spit and sputter for a second, then die) after letting it sit for a few it would start back up until it decided to do it again. On the vac advance, there should be two ports on the carb (one ported vac, one full manifold vac) Ported is above the throttle plate and gives little to no vac at idle, but increases as the throttle is opened. Manifold vac port should be below the throttle plate and will give full vac at idle, but decreases as the throttle is opened. Most 70's and 80s cars used ported.
Click to expand...

Ok thanks! Well, as far as I can tell, the carb isn't loading up anymore. We checked the timing yesterday and it was severely advanced so my thought was fuel wasn't getting burned off as it should. That problem seems to be fixed after timing was set..now its an issue of why it idled fine in traffic but stalled once throttle was applied? It appears something got too hot while in that traffic and caused it to stall when tried to accelerate? After it cooled down for 3 hours, it cranked up and ran like a champ all the way home.

Thanks again for all the suggestions!
 
Thank you 69jeepcj for clarifying vacuum. It is PORTED vacuum that is needed for distributor vacuum advance not MANIFOLD vacuum. And yes , that port is ABOVE the throttle blades in the body(upper) of the carburetor and not on the throttle plates (lower) part of the carburetor. A distributor wants vacuum above idle for vacuum advance which is needed on acceleration so that vacuum is found from the ported vacuum tube above the throttle plates. Manifold vacuum can only be used if needed at idle or is used by an emmissions era solenoid or vacuum delay sometimes used for distributor advance. Best to stick to simplicity as a ported vacuum tube directly to the vacuum advance canister will do the job. If emmissions laws hammer you , we'll deal with it then but we need this jeep to run now.
Wow , didn't realize that fuel line versus exhaust headers was an issue here ! Of course , it's a CJ , why would we not want headers on it ! What was I thinking ? I guess it's time to find a new route for the fuel feed line to the carb to avoid any potential vapor lock. Right about now , an ounce of prevention is worth a pond of cure. Got to remember my own signature ; never overlook the obvious , it's usually right in front of us.
Heqt soak is big problem that plagues ignition components and coils are no exception. Once a coil which a bottle type coil is packed in oil to cool it ( at least the old ones were) get hot , instant open circuit. Not good. Electronic ignition modules of all types fall prey to this too.
Just wonderfull , isn't it ? Well , I guess that's why someone wise once said that owning a jeep is like a second wife. Always needs our attention , care , love and money. So true.
Pit sounds like you got your hands full but if methodically approached , this can be done and with good results. Once you know your CJ that well , no mechanic will know it better than you.
 
Well...I think this is either coming down to a bad fuel pump. I couldn't even get it to crank this morning. Put a little fuel in the carb and it fired right up but only for a few seconds. Took the carb cover off and there is very little fuel getting to the carb at all. Went to Napa and ordered a new mechanical pump and filter...ordered a new coil too just for the heck of it. They will be in tomorrow morning. Hoping to put this behind me! Figure I'll re-route the fuel line a little while I'm doing it or at least insulate it in that area. If the new fuel pump doesn't work, guess I'll remove the gas cap and blow compressed air through the fuel line? One way or the other, this thing is gonna get running!!

Great info on the vacuum ports! I'll deal with the vacuum problem but I'm HOPING the fuel delivery snafu will be solved in the am!

I appreciate all the responses. Tremendous help!
 
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Best of luck to you . Hope to see good news in your next post , I'm sure we will. Hang on to the original ignition coil just in case the new one turns out to be a dud. Call me a pack rat , but I hang on to parts that did work to some degree , especially OEM parts since there's little faith in what is sold on today's market.
 
Case closed guys! Installed the fuel pump, coil and plugs. I put Autolite 65 plugs into...gapped them at .40. Anyway, primed up the carb and she fired right up! I'm thinking the main culprit was the fuel pump...maybe it was giving enough gas to idle in that traffic the other day but not enough when I needed to accelerate? Don't know and honestly don't care! Runs like a dream now.

Oh! The ported vac has full vacuum once rpm's are increased. All good there too!

Thanks for all the help fellas! I learned a lot through all this.
 
Another CJ nursed back to health . " I love it when a plan comes together " - Hannibal smith - The A team . Wishing you the best brother . Greg
 

Hi,
I would check a few things in the following order:
important is that if the intake flow should be ok but as well as the return to the fuel tank.
The pump is manual so will pump too much, the filter normally has a return flow.
Disconnect both and crank the engine and make sure there is a steady flow while cranking for intake and return, especially when you block the intake house. Be careful with the fuel flowing free. Replace filter if necessary or if blockage.
If this is ok, I would replace all rubber hoses. Leaving the fuel sitting tool long dissolves the rubber slowly and can block the flow.
Next, check if there is not too much rust in the tank, remove and clean if the case and replace the filter in the tank.
Next, get a kit for carb overhaul, replacing all rubbers and joints.
Hope above helps. I had to go through all of above to get mine working fine. I rather had the opposite problem: chamber in carb no filling up properly but it is more or less the same reasons.
Keep me posted, good luck.
Ronald
 
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