Intake Backfire Please Help

I just installed a Remanufactured Motocraft 2100 on my 75 CJ5 with a 304 in it. I have it adjusted so that it idles and runs great, however when there is one spot in the throttle were the carb spits. If I just barley push on the throttle that's where it's at in all 3 gears. I'm thinking the timing might be a hair off but I would appreciate any input. I've replaced the PCV valve, Vacuum Lines, Spark Plugs, and the New Distributor comes in in the morning. I think I have all the Vac lines hooked up correctly however my charcoal canister isn't hooked up. The Chilton's I have isn't very helpful that.

 

Every time I have had this problem it has been because the timing was a little off. Was it running at all before you replaced the carb?? If so, what was it doing and why did you have to replace the carb?

 

Yes I was running before I replaced the carb but it ran terribley. I replaced the carb because I had a broken choke and it was stuck wide open. What engine do you have?

 

Also I have headers and I'm pretty sure this changes my Vaccum routing any ideas. I'm lost here.

 

Your routes for the vaccum should till be the same.
I'd say the timing is off a tad.

 

That's what I figured I have no Tach any advice on setting the timing? And does anyone have a pic of their engine compartment and the Vacuum routing on a 304 to make sure I'm not missing something.

 

Mine was doing the exact same thing a while ago. The problem, in my case, was that the timing was way off and the distributor advance vacuum line routing wasn't even hooked up. Probably wouldn't hurt to check if they're routed correctly and if you have vacuum. From the intake manifold vacuum source, the line goes to a t-fitting. From the t-fitting, one line goes to the diverter valve and the other goes to the 3-port ported vacuum switch near the thermostat. The port to which that vacuum line goes is furthest from the thermostat. If I remember correctly, the middle port goes to the distributor. Hope that helps.

 

I appreciate the reply sud is there anyway I could get some pics?

 

With out having a timing light or tach the best way to do it is throttle tuning. Adjust/rev, adjust/rev etc till it sounds and revs clean,

 

The timing light I have just no tach

 

Dont need the tach with a light.

Just noticed you live in Owensboro KY.
A good friends wife is from there.

 

Thats funny most people even Nascar fans have never heard of it. Thanks for all the help J. I still think I may have a Vac leak some where when I bought the Jeep there were no Vac lines hooked up some I'm going by the Chilton's

 

Your welcome.
I hear ya, she went to school with one of the Waltrip boys. Cant recall which though. I'll have to ask her next time I talk to her.

 

Check out: http://www.jedi.com/obiwan/jeep/misc/vacuumhoses.html

For a diagram specific to the distributor vacuum advance, go here:

http://www.jedi.com/obiwan/jeep/wagoneer/pics/vac_advance_v8a.png

I believe you'll want to refer to the picture in the middle, which is what I have. I have all of those hoses pictured hooked up except the left-most hose. The one at the top of the splitter goes to the diverter valve (if you have it).

 

Oops, I have been gone this weekend so I missed your P.M. Looks like these guys have pretty much covered what you need to do on it though. As for pics of vacuum routing, I don't have any either and the CJ I have with the 304 has the engine out of it right now for rebuild some time this summer.