DoggyDiner

My 1999 2500 engine is surging while driving down the road. I recalibrated the APPS, which seemed to help, but 5 days later it is doing it again. Is the APPS going out or is there something else going on?

Thanks to all that replied to my post. I was able to connect the wire from the cab to the yellow/white wire and Bob's your uncle, it worked. Another issue with surging cropped up while test driving it. Thanks to Mopar1973Man's article and video I was able to reset/calibrate the APPS which cured that issue.

thanks for the simple explanation. Drinks on me.

OK, so now i'm confused. should I not connect the wire I have run to the fuse in the cab to the yellow and white wire on the old LP pigtail?

The FASS has an inline fuse and a relay before the wire to the fuse box and FASS fuel pump

Ok, so I don't need to add another relay as seen in your article? Just connect the wire that was run to the fuse in the cab to the yellow/white wire at the old pump pigtail?

I wish FASS had kept the wiring for the OE fuel pump to make things a lot easier. If someone could detail how to wire the FASS to the oe fuel pump pigtail, that would be great. I don't like the idea of a switch, because my wife drives it and she could forget to flip the switch to turn the pump back on. I'm a "dummy" when it comes to wiring myself.

Yes i wired the FP myself. I went by the FASS instructions. wired it to the pump, battery and to the fuse box in the cab. The pump comes on when i turn the key to run. The fuel pressure is around 15psi or so.

This weekend I got it up to normal temp. I tried starting it after about 5 to 10 minutes. it started as normal. I waited for 30 minutes or so, and tried again. Cranking was longer to start. I tried running cool water over the VP for a few minutes, still longer cranking time. I removed the fuse to the FASS fuel pump. It started as normal. I put the fuse back in, longer crank time. I waited for about an hour to try again. Longer crank time if I waited for the Please Wait light to go out. I tried cranking without waiting, it started as normal. How can I rectify the long crank time when hot? I've seen wiring diagrams on adding another relay to delay the LP from starting while cranking. I'm not really mechanically inclined or electrically inclined either. Does someone have a step by step with diagrams on how to do this? I have a friend who is a mechanic and does know a little about wiring that can help me.

How do I prevent the hard or long cranking starts?

It starts fine when cold. They rebuilt the original VP44 pump that came on the truck. It's not a Napa part. Napa VP44 pumps start at $1750 not including core. When I start the FP is around 14psi then build up to around 16. I'll see if I have the issue again this weekend, we will be hitting around 100 degrees here in CA.

Just found out the "Napa" IP was not a Napa pump but a local rebuild. Should I get a new IP?

Last November my original LP and IP failed. Both were replaced at the same time. The LP was a Napa stock replacement. It failed when I got home from a 900 mile trip. I took it to a shop and they diagnosed the LP failed. When I got it back with a new LP and pressure gauge, the LP failed after 2 weeks. I took it back to the same shop, it's under Napa's warranty, they replaced the LP again. Got it back, 2 weeks later the LP failed. Being fed up with the Napa LP dying, I researched online on aftermarket pumps. I settled on the FASS 95gph mounted close to the fuel tank. Got it started and running great. This past weekend, I drove it to pick up a heavy load of wood, the weather was warm but not hot. After I loaded the wood I tried starting it, it took a longer crank than usual, but it did start. When I got home I tried it about an hour later, same thing, longer crank time than usual. I have another long trip in a couple of weeks and don't want to be stranded. Is it possible that the IP is going out or that the LP has too much fuel pressure for the IP? I have the add a fuse connected in the cab of the truck to fuse 9.