Runs rough, best solutions/upgrades...
 

Got my truck from a close friend, knew it had great service history. Oil stays honey through 10k mile change interval, ran perfect... until I left town for work.
Got about 200 miles, started running rough, after a new lift pump and fuel filter. Gauge reads 20-21 lbs idle, 14 WOT, went from lke-new smooth to loping like a mildly cammed small block. Lost a little power and mileage, and after another fuel filter 2 days ago now stumbles bad at idle and low throttle. Has AFE Stage II intake with rig filter, straight pipe and older model Edge EZ chip. Just found out today the turbo bushing is shot, so it will need that, and there's almost 140k miles on factory IP plus idle time up north to avoid freezing, so likely needs that anyway. I wonder if since the smoke is only a black puff on startup, and if dead cold a couple minutes light white wisps smelling like a bad charcoal bbq, is anything other than the IP able to cause these mild symptoms, if changing the filter could cause a bad stumble the same day even tho it was done right and what mild injector/turbo upgrade should I do for the upcoming switch to an Edge Juice?
It already has a BD tranny so that's no issue but I don't want to go nuts here, just good mileage and a tad more power.

Well I got a great deal on a stock replacement turbo so that's what I will have for the next while. The previous owner had 75hp nozzles in this truck for a month and said it made no difference, although most of his driving was commuting 900 miles to his work site I assume those would only help power up top. My driving is more casual, but towing will be in the near future. I just want what will make it really boot if I meet rough hills offroad etc. Injectors, juice chip, powerpuck etc. Don't want to venture into head studs or anything.

Do you know if he got the injectors pop tested to the correct opening pressure when he installed those new nozzles? He should have seen a decent increase in mileage.

First thing first you need a fuel pressure gauge and an aftermarket lift pump. Those need to be at the top of the list. Check for codes with a reader and see if you are getting any trouble codes, that will help determine if the IP is going bad on you.

Only code was low voltage code 33 key cycles ago... right around when i got a new set of batteries. Still builds charge slow, need alternator rebuild, bout 11.7v going to the inj. pump atm and between 3.8 and 4.1 at idle from TPS not sure if thats ok volts for IP.
He got a pop test when he went back stock, they tested great for stock, I've never done diesel injectors so I dont know whats replaced besides nozzles when u order new ones... especially since they're like 80 canadian a piece thats not much.
The stock LP died so it has a Carter mounted on the frame at the moment, not sure if I should go 95 or 150gpm with the mild mods Im goin for, FASS is cheap at the local shop. My pressure gauge is pre-filter at 21psi idle and 13.5 WOT but its a bit jumpy even tho the pump is only 3 months old so I assume the gauge sensor needs to be moved or something.
Friend's dad is a mechanic out of his home, he is gonna check with UV light for leaks later today and make sure I didn't crimp a fuel filter seal or bleed it poorly.

Well my TPS is toast for sure, has about a 15% discrepency at idle and spikes repetitively as I apply throttle so I need one for sure, won't bother with IP or injectors till that's replaced. 500 at local shop, 200 on ebay but mine has an auto and the sensors online look different for autos but the same for a standard application somehow... but I can't find a story of anyone having a motor feeling like one cylinder is a bit off at all rpm from a TPS malfunction so we'll see how this goes. Smoke tested when TPS was done as well, no leaks, so that's good.

Lol well it finally startd to badly miss at idle and not when tps engaged the ECM so new VP and ran like new... For 2 days. Now rough and slow to start but can't find a leak. It's a Bosch factory pump. Defectivemmaybe?

Hate to drum up this old thread but I haven't seen info on this much, so in case someone knows... With all those new parts and still running lumpy I had a comp test done, all cylinders above 400 but 6 was 410, 3 was 420 and rest were 440-480. None too low, but some variance for sure though it was tested dead cold. Figure this motor is worth hanging onto? I will be in for a new truck otherwise, don't want to be in for 30k after a rebuild.

Did you ever put on a new LP?

Sure did, one of my first purchases, saw the pressure bouncing and did it same week. Fueling seems fine now, just have to know if the motor is solid enuf to invest in sticks and a juice, and likely a turbo mod to keep up with the fuel.

More than likely you have a 53 block which are notorious for cracking. But other than that you should be good to go.