Please Help!! 91 K5 Chatter when accelerating

[Messenjah]

My 91 k5 seems to have a chatter sound when accelerating or going up hill. Thought I would see if anyone else had this issue? Only happens when I hit the accelerator leaving me to believe maybe a possible fuel issue? Injector maybe? Thanks for any help

 

[dyeager535]

Chatter *sound* is unlikely to be related to fuel IMO, it would have to be a heck of a racket to make enough noise to hear over running, and not have you feel the problem caused by a fuel problem.

Chatter makes me think it's torque converter clutch, but doesn't make sense under the conditions you describe, unless it's malfunctioning.

 

[Messenjah]

I have found it not happening when upon initial startup of the day but soon comes after running awhile. I notice a performance loss as well when it occurs. It doesn't seem like a metal on metal sound. Hard to explain without hearing it I know, I just know it only happens when feeding it fuel and going up hills seems to trigger it most. Which might be because of more Fuel needed to climb??? could be more strain on the converter like you were talking about?

 

[dyeager535]

At what speeds? If you up or downshift, is it consistent with RPM or MPH?

I'm hoping someone else chimes in, I've never experienced a chatter sound, I can't think of much on the truck that operates in a manner that would create chatter outside of the trans.

 

[Fordum]

Sounds like detonation to me. What grade gas are you running? If it is detonation, you will definitely see a power loss when the knock sensor tells the computer about it, and the computer retards the timing to try and stop it.

If you are not running high octane try a tankful to see it it helps. That is not the correct fix, but its a good easy way to test for knock.

If it goes away or gets better with the high octane gas, you need to find out why its doing it.
Timing is off, its running real lean for some reason, or maybe an EGR problem.

 

[Can Can]

Sounds like a mid-throttle ping to me. Probably a timing issue.

 

[Blue85]

Could also be as simple as a bad spark plug or bad wire. Some of those ignition issues only show up when the engine is under load.