Is there any way to adjust to the accelerator cable?
How much slop should there be?

 

Have someone get in the truck and press the pedal to the floor....
You need to get under the hood and watch the throttle cable pull on the throttle "cam" and see how far it rotates.
It should rotate clockwise (toward the firewall) and when it comes to a stop you should not be able to turn it any further by hand...if you can it's just stretched a bit.
This part may seem a bit wacked out, but, stuff a small pry bar or whatever under the gas pedal and pry it upward then repeat the test.
On my truck I used a small a upholstry (sp???) washer. It''s about 3/16" in diameter and has a rubber backing on it. I slipped this over the cable end between the pedal lever/connection and the cable end with the "stub" on it. This was about right for me. On other's I've had to, and seen, the pedal forced upward as I noted.

pb.....

 

when my cable stretched past any adjusting i layed on the floor and slipped a electical grounding sleeve over the cable and lifted the pedal and crimped the sleeve on the cable next to the pedal where the cable went through worked real good and lots of room to adjust in the fut.

 

I just had my pump off last week when I had to replace the side cover gasket on my engine, and this gave me a good chance to check out what the pump looks like close up. My throttle cable was stretched a bit and I had fixed it by taking a 1/2 dia x 1/2 long aluminum bushing and cutting a slot in it running the length. Then I pulled back the slack on the cable at the pedal and installed the bushing over the cable through the slot. I then secured it with a ty- wrap. Now the cable is a 1/2" shorter. This was my fix I did about a year ago and it worked fine but when I had the truck apart I decided to do a better fix so I removed the 2 nuts on the firewall that hold the pedel bracket inside the cab. I then made a spacer 3/8" thick out of aluminum the exact size of the bracket and drilled holes for the bolts then I replaced the bracket to the firewall with the spacer inbetween. Now the pedel sits alot higher and it does not bottom out in the carpet at WOT. I have the D-350 LE and I have thick carpet padding over 1/2" foam core insulation that I installed under my carpeting to try and cut down on the noise. This was how I fixed my cable. Jim

 

I wrapped a couple of wire ties around the end of mine, cheezy but it was quick and works.