Random Shutter

[Huesmatg]

So i have a 1976 CJ5 AMC 258 i6 / 4.2l 6cy. All the emissions type systems have been removed and this is the most bare bones enough to get it down the road job.

its been doing good running around the neighborhood but now i get a shutter and it gets a little jumpy after running for 5-10 minutes and is generally when say shift 2-3 or 3-4 and there isnt much load on the motor. once youre in the gear and trying to build up the rpms. lower gear, higher rpms and there isnt an issue.

please help

 

[Lumpy Grits]

Check your U-joints for play.
Also ck your engine and tranny mounts.
Are the bolts to your skid plate tight?
LG

 

[Torxhead]

Try to figure out if it is mechanical or an ignition issue.

 

[Huesmatg]

Check your U-joints for play.
Also ck your engine and tranny mounts.
Are the bolts to your skid plate tight?
LG

Its got to be engine related i would think......

How do i decipher between mechanical and ignition? i was wondering if the vac advance on the distributor may be an issue but not sure how to check/verify?

 

[Torxhead]

If you have the oem style ignition, with a plastic vacuum advance housing, they do have a bad reputation. You could try adjusting the ignition timing a bit and making sure there is vacuum at the distributor. There are videos on the net on how to check for vacuum advance operation and distributor advance.

 

[Hedgehog]

Sounds like U-joint(s) to me. A bad one will "thrum" like a harmonic from time to time. But, I'm a little gun shy right now and could easily be wrong about this.

 

[Lumpy Grits]

Takes what, 5 minutes to ck all of your U-joints for play.
When was last time you lubed your U-joints and the slip-splines on your driveshafts?
BTW: The P/S engine mount is a known failure point also.
LG

 

[tarry99]

So i have a 1976 CJ5 AMC 258 i6 / 4.2l 6cy. All the emissions type systems have been removed and this is the most bare bones enough to get it down the road job.

its been doing good running around the neighborhood but now i get a shutter and it gets a little jumpy after running for 5-10 minutes and is generally when say shift 2-3 or 3-4 and there isnt much load on the motor. once youre in the gear and trying to build up the rpms. lower gear, higher rpms and there isnt an issue.

please help

Could be your clutch.........higher gears , more load........does it go away as soon as you back off the throttle?

 

[JR74CJ5]

Need a small clarification... Is the motor shuttering (RPM's affected) or sluggish, or do you feel a chassis shudder / mechanical?

If Mechanical, these guys are all hitting the nail on the head I think...

U-joints will cause a pretty good shutter / wobble you feel through the whole jeep.

Clutch is also a possible issue and Tarry suggested...

Let's try to narrow it down a bit, give us some more details. Even if you think they don't matter, they might...

 

[Bent]

A lot of shuttering and bucking going on this year. I had to go up from #46, to #49 jets on the MC2100 this summer. Don't know it its the heat up here or more ethanol in the fuel. I destroyed the gasket in the process. Its enough to make a guy do a fuel injection conversion.