Hi i have a 6.9 cant get it to run good when i bought it it ran fine now it misses sometimes and when you rev it up it smokes really bad and back fires it all started around the time the exhaust broke so we straight piped it can that cause it it smokes blue and smells like fuel any help will be very helpfull thank you and have a nice day

 

I'll translate that original post into English:

Hi. I have a 6.9 IDI F-_50 pickup Turbo/NA/mods with __,___ miles on it, and I can't get it to run well. When I bought it ___ days/months/years ago, it ran fine. Now it misfires and when I rev it up, it smokes really bad and backfires. It all went haywire around the time the exhaust broke at the manifold/up-pipe/down-pipe/y-pipe/muffler, so we straight piped it. It now smokes blue and smells like diesel fuel. Any help will be very helpful. Thank you and have a nice day.

I'm very skeptical that straight-piping an IDI would F up your truck, but who knows. More likely, your engine is lacking compression, the timing is off, and/or you have a stuck valve. Maybe by having some restrictive exhaust, your exhaust valves might be off, but I doubt it. Or maybe your IP is on the fritz. Maybe your rings are going to hell. Are you burning crankcase oil? If yes, then how much are you using every few hundred miles? How often do you drive your truck?

 

it burns 2quarts 800 miles its my daily when under a load it runs fine. what should the compression be at the engine has 130k original miles on it nothing has been touched

 

Every 100k it's recommended to get a new,
Injecton pump
Injectors
Retime the pump

Don't waste your money for any of that at a O'cReilly/advanced trash/auto break down zone

Try idiperformance.com
His stuff is basically unmatched in quality

Unburnt diesel is normally more whitesh. Blue is almost always oil related. Check the crd, it's like a big round pcv valve behind your intake. see if it's dumping oil in your intake

 

im going to advance the timeing first but prolly will get one anyways cuz its probably in it but ya i think it is dumping oil also thanks alot for the tips

 

Blue/white smoke and misfiring is timing, generally speaking.
IDIs will drink oil and burn it cleanly if everything is in good shape - heck, you can run 50% clean engine oil* in your diesel without any noticeable effects.

(*generally speaking, this would be waste engine oil, but it requires a very good pre-filtering to be usable or the crud will destroy your fuel system. Clean oil, however...)

 

well im fixing the rusty cab now on it i am going to advance the timeing a bit to c if it makes a change or not