Shake and lope at idle

[VolsFan]

Had this happen one evening this past week when getting mulch. While waiting to get 6 yards of mulch on the trailer noticed truck had a shake to it and standing out by the exhaust had a lope sound. Drove home fine. Has not done it since. Drives just fine. Only other thing I’ve noticed since owning the truck is a slightly longer crank time than I think there should be. Truck has new batteries. When the truck was parked out in the driveway with the nose facing down it fired up immediately. Puzzled, any ideas?
Also, it has an aftermarket pump on top of the tank, not sure why it’s mounted there and not the frame, as it’s loud in the cab. Also a fuel rail pressure gauge in cab as well

 

[seafish]

Idle surging or roughness is often caused by the FCA (fuel control actuator) being dirty or going bad.

You can check it by adding some marvel mystery oil to the fuel tank to see if the problem goes away, but since your symptoms are intermittent, that might not work. The genuine Bosch part is $115 at Genos and easy is to swap...Genos even has a link to a video that shows you how to do it.

https://www.genosgarage.com/product/actuator-4932457/fuel-system-accessories-replacement-parts

 

[VolsFan]

Perfect, sounds likely. I’ll be swapping that out and see if any change. I was worried it was the damper or something . Thanks

 

[VolsFan]

Thanks seafish that was my issue. Truck starts quickly now. It sure was a pain removing it. First two came out great bottom one not so much. Had to get creative but got old one out new one in. Never would have thought