Vehicle shudder around 6-700rpm

[jleffert]

About a month ago I noticed when I would be at a stop, take my foot off the brake and start to roll forward that the vehicle would shudder some. This also happens when slowing down to come to a stop but it only happens at very low idle speed, around 600-700rpm. Once I get past that there is no shudder at any other speed/rpm. It seems like it could be fuel system related, but I'm not sure. I tried running some injector cleaner through it and seafoam on 2 different occurrences,but they didn't seem to help. maybe fuel pump restricting flow too much at the low rpm?

Also my vehicle takes a few cranks to start, its been like this for years, but maybe its related..? Any help is greatly appreciated!

 

[rkntoy]

About a month ago I noticed when I would be at a stop, take my foot off the brake and start to roll forward that the vehicle would shudder some. This also happens when slowing down to come to a stop but it only happens at very low idle speed, around 600-700rpm. Once I get past that there is no shudder at any other speed/rpm. It seems like it could be fuel system related, but I'm not sure. I tried running some injector cleaner through it and seafoam on 2 different occurrences,but they didn't seem to help. maybe fuel pump restricting flow too much at the low rpm?

Also my vehicle takes a few cranks to start, its been like this for years, but maybe its related..? Any help is greatly appreciated!

Auto or manual?

 

[gamefreakgc]

Is it a shudder or a clunk?

The "clunk" is common for 4wd 4Runners if the the driveshaft has not been greased for some time, especially the rear slip joint.

 

[jleffert]

It's a 4x4 auto trans with 200k. It's definitely more of a shudder than a clunk.If I maintain light pressure on the brake and keep it in that rpm range it will continue to shudder for as long as I do it. Not sure if its misfire or what. Not getting any codes that would suggest that though..

 

[trap-alaska]

Mine was shuddering at acceleration, but around 1500 rpm, and it was the plugs. Changed the wires and plugs and the problem went away.