lack of power (top Speed ) and a very heavy accelerator pedal

[mattyboy]

Just bought a 1991 931a2 it is AWESOME. however on the journey home it only reached a top speed of about 53 mph. it has 14 r20 super singles, i have read owners going 60 plus. The truck was overhauled in 09 and has 1000 miles since and has MWO tag of 8/12 i will change all filters soon and i am running complentary diesel from the gov. about 90 gals. im hoping new fuel and filters will help. Next the accelorator, i dont have another five ton to compare. you have to mash the pedal HARD to go anywhere highway driving for more than a few minutes requires 2 feet on go pedal to maintain speed is this normal. on a side note i brought the truck home for my daughters 4 birthday and gave some rides to the kids what a blast.

 

[camoyj7]

Mine had three return springs on the pedal. I removed two of them and now it's much better to drive. Also pop off the linkage to injection pump and make sure it's going full throttle. You may want to check to see if your truck is in 6x6. I've checked 7 trucks and 5 had air lines to transfer case hooked up wrong. Bolkbich started a thread http://www.steelsoldiers.com/showthread.php?83799-M939-transfer-case-air-lines-installed-wrong

 

[mattyboy]

took a look at linkage all seems good took off heavier spring of the 2 much better not in 6 wheel drive have things to drive over and up at my shop that tell me so. there is a bolt that the pedal on the floor stops to i wonder if i back it down a bit would work better. i bought the truck last thursdsay as " runs with a jump" drove 200 miles home and to my delight started right up the next day. not so a week later. went to look at batteries one is low on acid so added water only to watch it spill onto floor from drain. the other 3 hadlevels that were acceptable. was pushing 22 volts at the slave hookup, i guess those extra 2 volts make a difference. next question/dilema do i buy 2 group 31 blems from interstate for cheap or one 6tl for 150 and hope that does the trick.

 

[Suprman]

I had one truck that the gas pedal pivot was rusted and jammed and as I depressed the pedal instead of the pivot moving as it should the whole floor was flexing. I took it apart and soaked it in wd40 it freed up eventually.

 

[doghead]

When you have 2 return springs and one breaks, you have one that still functions.

When you only have one return spring and it breaks, you have nothing.

Service your truck and use fresh fuel and additive before you modify or change anything.

 

[gimpyrobb]

Try typing better than a 4yo and I bet responses will improve...