Suddenly backfires

[Germy]

Driving cj around for a while today. Turned her off at the store and restarted about ten minutes later. I drove off and instantly noticed that there was no torque. If I stepped on it, it backfires through carb. So I gingerly applied gas to get up to speed. Once at speed let's say in third it has no top end and again, if I step on it it backfires through carb. Went to adjust timing and turning the distributor did not affect the idle. When I advanceed it in the past, the idle would increase, when retarding it would decrease. She idles fine. 360

Thanks in advance

 

[Germy]

Friday night, nothing to do! Does anyone have some insight?!

 

[Old Dog]

I would check your timing, you could have jumped a tooth on the chain.
A vac. check might tell ya somethime too.

I don't understand why turning the dist. (changing the timing) would not change the idle speed though.

 

[Germy]

I guess i should start draining the coolant! The gears are marked, correct? I have never done this, any pointers?

 

[Germy]

On the issue of turning the distributor with no idle change. Obviously advancing too far kills engine. Retarding also kills it. In between, there is little idle rpm change.

 

[Germy]

Found the temp wire disconnected at a joint. Could this be causing problems with the electric choke? Maybe keeping choke on?

 

[JR74CJ5]

Might be your culprit...

Check easy stuff before doing timing chain inspection... All plug wires in and good?

I would also suggest checking inside distributor for corrosion and if points style distributor clean and adjust gap...

 

[Old Dog]

Might be your culprit...

Check easy stuff before doing timing chain inspection... All plug wires in and good? .

IIRC you have a new HEI dist. right? You might want to also check that the advance is working correctly. Hook up a timing lite and make sure its advancing correctly.
The choke could be causing problems and or vac. leak.

 

[Germy]

I'm headin out there now, I'll run a timing light to check the advance. It is a new hei distributor. Im going to reconnect wire and see what that foes.

 

[Germy]

Choke is stating on! Just going to buy a carb. What cfm for stock 360? 600cfm?

 

[Old Dog]

When you say backfires do you mean one big bang or a series of smaller pops ?

 

[Germy]

It is a puff out the carb, I saw it when I had the filter off. Just shoots one big fog, the choke is on when it does this

 

[Germy]

I used a carb calculator for a stock 360, it came up around 500 cfm, is 600cfm too much, maybe 550? I have an eddy performer intake installed by po. Are there differences in the intake between a 2 barrel and 4 barrel?

Thanks!!!

 

[JR74CJ5]

(((360 x max rpm) / 3456) x .8 (if still stock built motor ie no major upgrades like cam heads etc) = cfm

If we assume 5000 is max rpm you would run, i get 416.66667

If we assume 6000 rpm = 500 cfm

The 600 cfm would probably be fine as the cfm ratings on carbs are overexagerated by suppliers mostly, but not positive on this...

Now are you sure you want to just get a new carb, not repair old one? Im that way too but it could save you some $$ if repairable...

Either way

 

[Germy]

I am replacing everything as I go, carb was inevitable.

 

[Old Dog]

sounds like fuel injection time. You won't regret spending the money.

the ONLY carb that I've seen work well offroad is the mc2100.
the truck avengers , edelbrocks, and webers are ok but not as good IMO.

 

[Germy]

Old dog, I do not think that this cj will ever see mud. Too much time and money. Ive got my feelers out for a CJ5 with some heavy components. Something that looks terrible but is tough. I would cry if my current rolled or got into it with a tree!

 

[Purple77CJ7]

I agree with olddog, if you can swing it go fuel injection. I like the Howell TBI on my jeep. No comparison to a carb. I have no regrets. Did nothing but fit the carb that came on this Jeep when I bought it.

 

[Germy]

I looked at a few. Looks to be around a couple grand. Dear god.