its not new but its new to me 94 12 valve ran great coming home i noticed it blew a little blue smoke when i started it but i figured it was b/c its been sitting for awail drove it home ran great now its being dumb... when you first start it when cold it studers and pops a little around 1800-2200 and blue smoke comes out let it worm up to temp and it doesent do it as bad not as much blue smoke and not as much studering, take off with it and go up the road it runs good no smoke really or any studering, drives just like when i drove it home, any idea's? it also feels like it has less power than my last 12 valve idk if its b/c its stock and my last one had some stuff done to it (fuel plate)(pump turned up) or if there is something wrong they where both same trucks just two years difference

 

Sounds to me like either the fuel pressure is too low, air is getting in the fuel, or the injection timing has slipped. All will give those symptoms.

The first step is to replace the fuel filter and clean the prefilter screen. Next, if you have access to a fuel pressure gauge, hook it up and verify fuel pressure. Should have a minimum of 18 psi at idle, and should rise up close to 30 at full throttle. The lift pump or the overflow valve can fail and cause low pressure.

Have a good look for fuel leaks from the tank to the injector pump. Give the rubber return hose a good look for cracks and wetness at the back of the engine, over the bell housing.

Next step is pump timing. I won't describe it here, but do a search and there is plenty of info.

Hope this helps.

 

Ditch the fuel heater and make sure the grid heaters are working. Add some fresh fuel/change the oil and the appropriate filters for both; then see what you have. If it sat for an extended period of time you need to start a new baseline anyway. good luick

 

changed fuel filter and oil filter with oil, put injector cleaner through it fresh gas and still does it, all this i did helped but the problem is still there, i got looking under it and my frame rail and tank is wet wit diesel so im thinking its getting air thats my next step if anyone has any other ideas let me know, i dont have a fuel pressure guage to see what its running at

 

i mean diesel not gas lol