Engine/Transmission (1994 - 1998) new injectors & now lugging in 4th gear

[SFrancois]

I installed new Industrial fuel injectors . " I think the injectors are a little bigger than stock, 50 hp? Now my truck is lugging in 4th gear. I think it's burning a little rich. Light haze of grey smoke" when leaving stop light. It starts fine and idols o.k. but I'm burning a lot of fuel. Could it be timing? star wheel?air leak? too much fuel?universal joint in drive shaft?

P.S. I will install a FASS fuel filtration system soon

1995 stock, 2wd, no catylitic converter nor fuel heater, stock rubber & metal fuel hoses

 

[GAmes]

Diesels don't burn "rich". Forget everything you ever knew about gassers when you pop the hood. Not knowing what injectors you removed or the size of the injectors you installed gives us little to go on. Lugging in 4th just means you need to shift at a higher rpm. Advancing your timing should increase your mileage, but it will also increase the rpm the turbo starts to spool. You can't beat a stock lift pump with an overpriced, not as reliable, electric pump. The overvalved crowd can probably benefit using a FASS, but in your case, save your money. The mechanical pump will easily support 300HP, and with a little work 400. The Fleetguard fuel filters are more than sufficient for the P7100.

 

[Missouri Mule]

Auto or 5 spd ? if it I is auto probably trans. Agree need to advance timing a little.