Carb question

[Megamus]

Having some issues with the cj running. Some cylinders are firing and others are not. Thought it could be carb related. I thought maybe there could be something wrong with one of the barrels on the carb. Its a 2 bbl on an amc v-8. Does anyone know which port of the carb is tied into what cyl?

[tjblair]

Sounds like a spark issue. I think both barrels feed all cyl.

[Megamus]

no its not a spark issue... Every cyl is getting spark.

[Megamus]

i also think 1 barrel feeds 4 cyl and the other feeds the other 4

[tjblair]

Maybe, I'm not sure but I don't think so. Unless there is some sort of baffle in the manifold. I use to have a 304 in my cj, but that was in high school. And I can't remember that long ago.

[tjblair]

Have you done a compression test?

[Crazy C]

I does sound like a spark issue check your cap and rotor for corrosion pulling the plug may show spark but with fuel it may not be getting enough to fire. other than that as tjblair said compression test each cylinder. If you have a thermo gun start the cj then check each cylinder at the manifold to see witch are cooler this is an easy way of knowing witch ones are not firing or you could just feel them but they will get to hot to touch quick.

[mxg342]

Are you running a stock carb and intake?

[stesul411]

Which AMC V-8 is it, 304, 360??? What brand of carb is it, Holley, Motorcraft, Rochester, Carter????
It is possible that it may be a dual plane intake, where the right carb throat feeds the left side of the motor and the visa versa. Chrysler used dual plane manifolds on almost all of their carbed V-8's, not sure about AMC, Ford or GM.

Have you had the carb off of the intake?? If so were there single bores under the carb, or just one large oblong bore???

[92YJCBG]

its a 360, I talked to him yesterday about it.

[tjblair]

Which AMC V-8 is it, 304, 360??? What brand of carb is it, Holley, Motorcraft, Rochester, Carter????
It is possible that it may be a dual plane intake, where the right carb throat feeds the left side of the motor and the visa versa. Chrysler used dual plane manifolds on almost all of their carbed V-8's, not sure about AMC, Ford or GM.

Have you had the carb off of the intake?? If so were there single bores under the carb, or just one large oblong bore???

That's kind of what I was getting at. My 304 was a single plane intake. Bit I don't think it was stock. I'm pretty sure it was an eddelbrock. Or how ever you spell it

[Megamus]

lol ok let me be a little more clear. it has a BRAND NEW hei dist. every wire and every plug is new. ran the compression test, and every cyl is fine.

As far as which cyl are firing, its every other one in the firing order, meaning 3,5, 2,8 are firing, and thats it and i wanted to know if the one barrel effects 1, 7, 4, and 6.

Its not just not sparking, that was the first thing i checked


the intake was split.

[mxg342]

OK I'll ask again with a little more clarity.

Are you running a stock intake and carb, BECAUSE, I have three stock 2bbl intakes sitting in my barn. I will take a look at them to see if this could remotely be the cause.

[DMG]

When you swapped the HEI in, did you run it to full battery voltage instead of through the resistor?

Is it missing at idle? High rpm?

Did you pull the plugs you think are not getting gas and see if they have gas on them?

[Megamus]

Yea its a factory carb and intake. Sorry, missed you post. and that would be great. Thanks

OK I'll ask again with a little more clarity.

Are you running a stock intake and carb, BECAUSE, I have three stock 2bbl intakes sitting in my barn. I will take a look at them to see if this could remotely be the cause.

[Megamus]

When you swapped the HEI in, did you run it to full battery voltage instead of through the resistor?

Is it missing at idle? High rpm?

Did you pull the plugs you think are not getting gas and see if they have gas on them?

i did run it full battery voltage. What resistor?

its missing at every rpm

i did pull the pluggs and there is some liquid in them, however not enough?

[MF Steve!]

Sounds like the 360 version of The Punisher...

[mxg342]

ok I checked out the intake.

It is a dual plane intake with the drivers side feeding cylinders 1, 7, 4 & 6.

The passenger side feeds cylinders 2, 3, 5 & 8.

The only connection is right under where the carb mounts. There is a "hole cut between the two ports in the intake. Other than that they are split all the way to the cylinders.

I have a stock carb for a V8. It's been off the Jeep for a while but if you want it you are more than welcome to buy/borrow it to see if that's the problem. I will be down at BeaveRun next Saturday for a hrja trailride so I'll be in the area.

[ArtCloud]

Seriously... did you try spinning your distributer 180*. I've seen this happen a million times and you get the same symptoms you are describing, you still get all 8 cyl sparking but the engine will be 180* out of time. This results in a barely running engine with a ton of sputtering and backfiring.

[tjblair]

Seriously... did you try spinning your distributer 180*. I've seen this happen a million times and you get the same symptoms you are describing, you still get all 8 cyl sparking but the engine will be 180* out of time. This results in a barely running engine with a ton of sputtering and backfiring.

agreed I've seen the same think when they are stabbed 180 out. But who knows?

[Megamus]

ok I checked out the intake.

It is a dual plane intake with the drivers side feeding cylinders 1, 7, 4 & 6.

The passenger side feeds cylinders 2, 3, 5 & 8.

The only connection is right under where the carb mounts. There is a "hole cut between the two ports in the intake. Other than that they are split all the way to the cylinders.

I have a stock carb for a V8. It's been off the Jeep for a while but if you want it you are more than welcome to buy/borrow it to see if that's the problem. I will be down at BeaveRun next Saturday for a hrja trailride so I'll be in the area.

Ok thats what i was hoping for. Thanks alot for the help and for checking it out for me. I will let you know about the carb here soon. Im going to pull the carb off tonight to see if something is wrong.


Im positive the distributor is correct. I have turned it 180 degrees about 200 times trying to fix this problem. i guess one more time wont hurt

[mxg342]

As a quick test, just change your plug wire locations on the distributor cap 180 degrees and see what happens. If it runs better, you know.

[jackb1]

Did you make your own plug wires? I always have to do it for my AMC V8 and my first time doing it I messed up a few and wasn't getting spark. Got a way to transport it to Shaler? I've got one running you could swap parts off until you get it figured out.

[Megamus]

Did you make your own plug wires? I always have to do it for my AMC V8 and my first time doing it I messed up a few and wasn't getting spark. Got a way to transport it to Shaler? I've got one running you could swap parts off until you get it figured out.

Make my own wires? No i just bought some. Why would you need to make them? Too short?

[jackb1]

One size fits all type kits... you have to cut the wires to length and put on the ends yourself. I end up having to use them a lot and I hate it every time.