So I have a 96 290k miles 5 speed afc live gauges hx35. Newer injectors. It started awhile back when I free rev it especially when it's cold it pops and white smoke. When I'm driving it it will do it a little when cold and none when it warms up a little. No matter how warm it is when I free rev it it will pop and white smoke. It runs great pulls hard going down the highway fuel pressure is good egts are normal. Engine appears to have little to no blowby. Recently after a long trip when I come to a idle it started missing sounds like on one cylinder. I looked some things over and did the fuel heater delete with no change. I also adjusted the valves and after a few hundred miles with no change double checked them just to make sure. I was thinking from my research small fuel leak, timing slipped or maybe needs an overflow valve. I was going to drop in a new draw straw and 1/2" line to the pump when I empty this tank out just to rule out air because the lines are fairly old. Am I on the right track? I've never done timing but have been considering checking it. Thanks.

 

i would start with a ofv, most people over look them. and cheap insurance. other than that your on the right path. fuel leaks/ air inclusion. low fuel pressure, failing lift pump. you don't say if you have an electric or stock. and finally a timing slip. which would be pretty low if it slipped low. slipping high doesn't usually cause any issues other than more power

 

Once you make sure you have good pressure and no air getting to the pump, I would check the injectors. It's easier to take them out and get them tested for free before you pin your timing again. I had an injector that was pissing like a squirt gun and it makes for rough running. Hopefully you have a shop to test local, or if you had your eyes set on a new set you could always give that a try. And if you or a buddy have a compression test set you could always rule that out when you do injectors.

 

stock lift pump but it's 20 at idle 25 cruising down the road. I'm going to order the overflow valve kinda seemed like cheap insurance too. I already did new injectors mine were realllly old and I got a killer deal it ran a little better but not much. I've already got a new draw straw for the tank so as soon as I get it down below quarter to 1/8th tank I'm going to drop the tank and run a new line to the lift pump with 1/2" line. I'm trying to not go the route of a new lift pump till it's needed. Mine seems strong. wot I've never seen below 20psi. I guess I'll update in the next week or two with what the overflow valve and new fuel line does. Thanks.

 

It will be interesting to see if that helps at all. It seems like its not a fuel pressure related problem considering yours isnt bad but also my truck will run fine without any fuel pressure until its under load. I found this out when my old raptor **** out. would start idle and rev pretty normal, under load was a joke though. It might be worth it for you to re pin your timing. It seems like a daunting task but isnt bad at all after you do it. then you could cross timing out on the possibilities list!

 

Ya that's going to be next after doing the fuel lines I'm still trying to run it down so I can drop the tank unfortunately I filled it right before I started trying to trace all this down. I'm down to half a tank. I know my pressures are great I hauled a 9k load today and tons of power under a load I'm just wondering about air in the lines mostly. I'm hoping one of my friends can help me my first time doing the timing.

 

Got the tank ran down and did it this weekend and overflow a couple weeks ago. No real change with either. My fuel lines looked rough but they're all brand shiny new now along with the dip tube. It's still doing it. I just still have a hard time believing it's timing it still fills like air to me. I could be wrong but most of my old diesel friends agree. Anyone in NM fill like helping me check the timing I have no clue how but I figure I'll be teaching myself shortly if I can' figure something else out.

 

upgraded injectors is there a fuel line pressure set. 94 dodge ram 2500 cummins 5.9the injectors are 50+ hp the stock set is 25 pounds.