Jeep not running right

I have a rochester 2G carb on my '70 cj-5 with the 225 V6 engine. It was running fine until it started stumbling and bucking violently and then stalled. It seems like it was starving for gas and then it would get some and run. It started backfireing when I tried to start it. I finally made it home after starting it and driving it until it would buck and stall and I would let it sit for a while and drive some more. I know the timing is right so I suspect the carb. The trottle plate rod is sloppy and drips gas onto the intake manifold and the other end of the rod is open. It seems like there should be a plug there. Is there any way to fix the slop in the trottle plate to keep gas from leaking out and air sucking in there? I have it off and am going to rebuild it but think it may be a waste of time if I can't stop the air/gas leak. Anyone have a similar problem?

 

Back fires are mostly an ignition problems. you didnt say what ignition you have.sloppy throttle plates doesnt cause a sudden running problem, they are consistent minor problem. moisture in the distributor will cause what you disscribe,

 

I have a prestolite with new pooints, condenser, plugs. I noticed I wasn't getting gas to squirt down the carb when I worked the accelerator and I took the carb apart and the accelerator pump rod was not attached to the plastic plunger. Could that have caused it to act that way?

 

Two problems...
There shouldn't be enough raw fuel in the carb throat for gas to leak out the throttle shaft, no matter how loose theyare. I suspect a float or needle & seat problem.
Secondly, if the throttle is significantly worn, it will cause a vacuum leak around the throttle shaft. This will mostly manifest itself in idle problems.
The 2G Rochester has a cast iron base plate and isn't known for worn throttle shafts. It's hard to say without seeing it, but I suspect that if you cure the fuel drip it'll be OK.

 

I'm going to get a rebuild kit and clean it out before installing. Also check float level and replace accelerator pump assembly.

 

Sounds like something in the tank closing off the fuel pickup, or a partially clogged fuel filter.

 

If fuel is leaking past the throttle plates I'd look at float needle and seat first. I'd also look at the complete fuel system for fuel delivery issues. A lean condition can also cause issues like you describe (fuel starvation). You may have multiple issues going on caused by debris in the fuel system. The accelerator pump issue you describe will cause stumble during acceleration and is certainly a factor to consider

 

Quadrajetparts.com sells throttle shaft bushing kits to repair worn throttle shaft bores

http://quadrajetparts.com/rochester...-for-516-carburetor-throttle-shaft-p-286.html

 

i agree with nick schmeg in the fuel causing a sticky float and plugged idle jets . take it off and clean it.

 

I just had the Pertronix #1156 and matching coil put on my 225 v6 and after one week it is running smoother than ever. I also had the 2G carb rebuilt this past year so the combination so far is very good. As of now I would recommend the Pertronix module and coil upgrade. I run the Rubicon this weekend so that will be the real test......
Peter

 

Thanks to all for your suggestions. I will work on one at a time and keep you updated.

 

3 years ago my Jeep, just bought, was out of use. Today it works perfectly, I am myself surprised. Positively.
As soem specialist on the forum say, and as you understand, check subjects one at a time.

1 - I had a bad fuel gauge so I had problems because ... lack of fuel.
2 - the spark plug problem : I checked and changed what had to be changed, on plug was broken, difficult to see.
3 - positioning the timing : when it is well positioned, it runs and starts perfectly.
4 - checking the valves (can be useful)
5 - fuel pomp : I got a new one, I use it by hand when the car stays 1 week or more without running
6 - carb : accelerator pump checked, cleaned; in fact these carbs need to be cleaned because we drive in dirty ways.
7 - check the mass to have good electric contacts. It becomes dirty and can cause problems.

I am not a specialist in cars, these Jeep are old cars and problems are not obvious. Takes time to control all.

 

It says for 5/16" shafts for quadrajets is the shaft the same as a 2G?

 

What is the model #, make and year of your distributor. I can't find a Pertronix for my prestolite distributor. Also what type plug wires are needed for the coil upgrade?

 

You need a Delco distributor for the Pertronix conversion.

 

I want to say yes but I'm not 100% sure.

 

I opened the point gap and finally got it to start for a few seconds. Pulled all the plugs and they are all covered with sooth. Could the throttle shaft leak cause this? the only thing I didn't take apart and clean when I rebuilt the carb was the power piston since it was staked in pretty good and I didn't want to break it. The distributor came back after rebuilt and had an external oiler which I removed because it was in the way. Could that have caused problems? Running out of things to check.