help truck idleing funny

[kkbodyshop]

95 f350 turbo 214k miles truck is stock other then straight pipe an napa 6673 filter. truck shakes when idleing an smoothes out when you give it a little throttle. it has felt like it has died a couple of time driving down the road but is still running . i replaced the cps today. when i unplug the icp it runs the same . sitting at the stop light it ildes up a down a lil like its under a load. the icp wiring lookg good an no oil is in the plug. im at a lose with it. please help

[kkbodyshop]

it has a new ebps an i have cleaned the tube

[kkbodyshop]

idle smoothes out when i give it throttle at 2 grand rpm. it has 2 new batterys but volts guage is dropping. battery light is blinking when i rev it up

[madpogue]

Does the volt gauge go back up after the GPs time out (aprx. two minutes)? If not, alternator is your prime suspect.

[kkbodyshop]

had my truck checked out 2 day . guy said i need injecters. he also told me to put a qt of marvel mistery oil in the oil an sum trans fulid in the diesel tank an drive it. i have done that an it seams to run a lot better. he gave me a great price on a set of stock injecters $1600 an a set of stage 1S $1650. has anyone ever heard of the mm oil trick?