it ran great until recently. i have done all the work myself. custom fuel plate, milder than a #10, air box mods, 4" exhaust, and gauges. two days ago it began to stumble at low to mid rpm's. today i changed the air and fuel filters, no change. it smokes black a little, gets worse when the stumble starts but once the stumble clears it cleans right up.its not a hot rod, i just turned it up a little so it was easier to drive. i also tried readjusting the afc, thought maybe the star nut moved. i can crank the star nut way back and it still does it, just no power. 3/4 of the way forward it stumbles the same but runs good. im lost cuz its been running great for months. any ideas on what to check?

 

could be losing a cylinder because of a bad injector

 

well i installed new injectors today and they made no improvement. i have noticed a ticking that is getting louder. i check the valve lash today and they are all right on the money. any more ideas as to what the problem might be?

 

is the ticking loader on the driver side than the passenger side? if it is i have already experianced it, it would be your lift pump craping out

 

no kinda center of the engine maybe a little to the passenger side. cant hear it at idle only around 1500 rpm or higher.