cadash

Got a 94 12 valve I sold to a buddy of mine. Was gonna be turned into a pulling truck but I needed injectors for my other two trucks and had to sell it. Well we got it running and idling fine. It takes quite a while to start and when it does at idle it sounds good with a little white smoke. Dash gauges don't work so I'm not sure of the exact rpm but at approximately 2k it spits, sputters, shakes, backfires and white smokes BAD! Get off the throttle and it idles fine. No shaking. Previous owner said he put marine injectors in it but screwed up the timing. P pump is stock but do have bigger delivery valves. Had a buddy of mine "fix" the timing and he's credited with getting it running. Does not know what he set it to. Known issues: number 5 injector return/balance line washer is leaking, p pump pressure line leaks a little bit, dash gauges don't work and there is a line by the turbo that goes to the p pump that's disconnected with a bolt in it. Picture below. So can any of the known issues cause this? If not what can do this? I hate having sold the truck like this but he was fine with it. Just want to get this thing running good.

Tate

It could definitely be a timing issue. Fouled injectors would be another cause. Swap in a set of good injectors to rule that out. Tough to say with the timing if you don't know where it is. The fuel leaks won't contribute to the white smoke and stumbling, usually just a miss with the hi-pressure lines, low pressure lines will just pour fuel out. The line from the turbo to the p-pump would be the wastegate line. That being blocked off would be no cause of your issues. Swap injectors, and get someone who can time it properly so you know what you're dealing with.

cadash

Did some reading about the over flow valve. Checked the truck for one and sure enough it didn't have one. Got one installed and it didn't fix it!! It was a used one so it's 50/50. Gonna try injectors next.