I'm running out of ideas here guys. When I got the tuck it wouldn't free rev past 2700 and could barely get on the freeway. Knowing full well this was a Band-Aid I uncapped the limit screw for maximum accelerator and backed it all the way off. This got me about 3200 rpm and turning it by hand, the linkage couldn't even reach the screw anymore.
- New fuel filter and 4 tanks later still no big improvement. Fuel cleaner/ lubricants where added to each tank.
- Ruling out the rest of the fuel system I ran the pump directly from a fuel can and was still limited to 3200 rpm in park and neutral.
- Fresh oil, fresh air filter, all valves adjusted to 0.014" (.35mm)
- The engine fires up instantly as long as you wait for the glow plug light. It runs smoothly above 900 rpm with a little shake below that speed.
- Acceleration is smooth but lacking power.
- Turbo hits 5psi before 1500, 12psi by 1800 and If I stand on the brake pedal I can have 12psi at stall speed. So nothing wrong with boost.
- I do get puffs of black smoke under heavy skinny pedal they are less now than when I first got the truck.
- I have not checked if the accelerator linkage is a spline or two off but that was mentioned to me. It doesn't appear to be so but I can try to move it over a spline and see what happens.
- I have not checked pump timing but I'm told that would not prevent revving unless it was so far off that I would be having other problems too. (starting, stumbling, excessive noise, lots of smoke etc...)
- Checked banjo filters on pump: no filter on inlet, inlet hole is clean. Filter inside outlet bolt was dirty, cleaning had no effect.
- Oscilloscope is on the way so I can verify the tach