Carb Issue?

I have a 71 cj5 with the 225 v6. Everything was running fine but on the way back from a trip, starting having problems running right. it started running rough at the high end. finally would hesitate really bad when starting out and run ok in the midrange. Thought it was something to do with the fuel.... put new gas in with some sea foam. changed the fuel filter. blew air through the fuel line back into the tank. Has a electric fuel pump which has worked fine up until now... It pumps fuel but do not know at what pressure. Rebuilt the carb. Now idles fine, but when accelerating off idle hesitates bad runs will in mid range and will not run at high rpms. If you go really slow on the accelerator, it picks up fine until high rpms and then it bogs down.

 

Sounds like the fuel pump may be dying. (One possibility.) Check the pressure when the engine is under load.

 

check your dwell if you have points

 

You probably already did this but if not, check the screen where the fuel line connects to the carb.

Could it be the coil getting weak?

 

Open the top of the carb again ( I am assuming it is the rochester 2g), double check your float level/drop setting and make sure the accelerator pump, linkage are all correct. make sure the little check ball at the bottom of the accelerator pump chamber is in place. Look for junk in the bottom of the float chamber.

 

ongoing saga... fixed one problem another came up.....

ok... I checked the fuel pressure. It is running about 5 to 5.5 lbs. I changed the fuel filter in the carb. I adjusted the float drop and I adjusted the linkage to the accelerator pump. runs much better now at low rpms. BUT when I get to high rpms it does not run well... hesitates and kinda back fires... I am at 6300 feet and running size 48 main jets... What am I doing wrong now?

Thanks

 

Check your vacuum advance.

 

And put in a new air cleaner element.

 

I had similar problems with my 225. I Finally had the carburetor professionally rebuilt and it runs great! I now wish I had taken it in much sooner.

 

If you haven’t already try ^this.

 

put in a new air filter, rebuilt the carb, increased the main jet size.... all to no avail. The problem was that the points were bad (wore out). replace the mallory dual point distributor with an HEI and everything is running fine now.

 

This is a perfect example of the difficulty the members have of trying to help solve a problem. Not being able to look at the vehicle itself and no pictures of the engine (or problem area), there was no way of knowing the engine did not have a standard distributor in it. The person asking for help will help himself by providing lots of information. More is much better than less in these situations. In some cases it's harder than pulling hen's teeth. Just saying.

 

I think the members here did a great job helping me with my issue. There were several suggestions to look at the electrical side of things... I just had it in my head that it had to be the carburetor and did not look at the points until I had done everything possible to the fuel side of the equation... Next time I will check both before concentrating only on one side of the equation.