bad surging when accelerating

thanks to all who helped me out with washer thickness. But now i have a real big problem so i started a new thread.

I have been having problems for a while now when i accelerate hard or lug the engine any if feels like is bucking or skipping. So i replaced the ve pump about a moth ago and that didn't help. today i replaced the injectors with new ones . It still has that skip feel but not as bad. But now i have a new problem that is quite bad. if i accelerate hard or try to maintain 70 on the highway i get a hard surging up and down . hard to explain but its like vroom vroom vroom . like I'm pumping the gas peddle up and down fast, pretty much underivable. I have a gauge on the dash and it never drops below 6 pounds. Im really stuck , I've put in 2 ve pumps and 3 sets of injectors. Any one have even a wild guess ?????

Throttle position sensor?

Are you confident the boost line from the head to your AFC is clear and not dislodged with something?

Is your fuel pin indexed correctly inside the injection pump?

Sounds like a fuel related issue to me.

Fuel is easy enough to check. I was just starting to look online for a new VE also, my truck was surging so bad and stalling. When i drained some fuel from the filter into a clear container, I had more water than fuel.

Took the tank out, drained a good 1/4" of water from the bottom.

For good measure, I took all the fuel lines out, to see if I was sucking air anywhere. Went right from the bottom of the pickup in the tank to the pipe thread fitting inlet to the lift pump(capped off) Held 125psi, testing both quick connects and the tank module too.

Next i plugged off the return line, also at the bottom of the pickup, and applied vacuum straight through the lift pump, heater, filter, inj. pump and it all held. No leaks anywhere.

Cleaned out 24 years of gunk from the bottom screen of the pickup (in tank) and made sure that floating pickup system works.

Finally, cleaned off the sweep contacts for the fuel level sensor, restoring that back to proper operation.

Welded up a new tank strap(rusted out), and I have to say it's been problem free for about a year now.

I also finally plumbed in my gauge, 3-5 psi from the original lift pump.


Mike