hi guys i have a 96 3500 and i having probs starting it takes 4 to 5 tiimes trying to start before it will start when it starts it will run a little rough and blow out white smoke then after a few mins it will run good and start good all day unless it sits for more than 4 hours then the same thing i have replaced the fuel heater & fuel filter & the air heater relays that seams to all work fine but it didnt fix the prob i then took it to a dealer for diag. advice they said the fuel lines were rotted so i replaced them from the tank all the way up and the rubber hoses it got a little better but still the same prob. could it be the Lift Pump?? where do i look next any advice would be great thanks

 

Two things come to mind. You timing may have slipped or the overflow valve may need replacing.

The overflow valve is not expensive and can be had by calling Marty Tompkins. Don't have his number handy but if you will do a search it will show up in one of Infidel's posts. Easy to replace, one wrench job, but don't let the washers get away from you or they will drop down the side of the engine between the fuel pump. Over time, the spring in these rascals gets weak leading to lower fuel pressure by letting more fuel into the return lines than in the feed lines.

I would try that first if it has not been changed out in the last 50k miles. If that does not get it I would check the timing. You can also do a search on that as there are good instructions on here. With the timing, the unfortunate thing is that it takes a couple hundred dollars of tools (dial indicator and gear puller) unless you can find someone with the tools willing to help.

Let us know how it turns out.

John (DH)

 

i checked the overflow valve and the spring and everything is intact

 

Dave, have you ever changed the rubber fuel lines (supply and return - 2 at the front and 2 back at the tank)??

 

overflow valve and timing....IMHO...especially since u looked at everything else...

ps is ur fuel shut off solenoid coming up fully before starting?...u cant tell if ur overflow valve is good just by looking at it...there is a PITA test for it though...


for timing:
http://dodgeram.info/tsb/1994/18-10-94a.htm

for overflow valve:
http://www.dodgeram.org/tech/dsl/tro...p.htm#Overflow

 

yes i have changed all the lines from the tank all the way up and all the hoses on the motor, the fuel shut off solenoid is working, i think im going to to replace the overflow valve if i can get one in the AM and if that dont do it im goina replace the LP !!! if that doesnt do it ill replace the injectors any ideas on what size injectors i should get and where is a good place to get them? does this sound like a good plan? there is no one around here that really knows diesel id like to get the timing checked i had it to a dealer but i dont trust them i want to "thank all of you for your input"

 

Before replacing the lift pump, you could check the fuel pressure at the inlet to the P-7100.

You say you replaced the fuel filter??? - Did you check/clean/replace the pre-filter??:

http://www.dodgeram.org/tech/dsl/fil...filt_clean.htm

Another question.....have you had the timing checked/adjusted??

Stick around - someone will get it figured out before long. No need to dump a bunch of money on parts if you dont need them.

 

the fuel heater and filter is new i changed that first, i havent found anyone to check the timing as of yet, and i can not do it myself i dont have the tools i dont have anything to check the pressure with what do i need?

 

I agree with Evil, check fuel pressure first. If ok , it may be as simple as adjusting idle rpm ( increase )

 

You can go to a parts store and get a fuel pressure gauge to test with. You will need a hose to fit on the shrader valve on the P-7100.

 

Well Good News I Think!!!! I Found The Problem Just For The Heck Of It The Truck Was Stone Cold This Morning And I Decided To Pinch Off The Return Line To The Tank And See What Happens And Presto It Started Right Up I Only Let It Run For 10 Seconds And Unpinched The Line And It Started Right UP Again With White Smoke Tho As Far As The Smoke I Dont Know? Im Just Happy It Fired Right Up So I Think The Overflow Valve Spring Is Weak And Letting To Much Fuel Return To The Tank So I Just Ordered One Form P.d.r (piers Diesel Research Inc) It Will Be Here On Monday Ill Let You Know If It Fixes It ( I Think It Will) I Want To Thank You Guys Again For Your Help & Input Dave

 

Bingo

John (DH)

 

or you can just fix the overflow valve by yourself,

by taking it out with a 3/4 wrench, then removing the bolt onside that valve, with a 9/16 wrench, be very careful by taking it apart on a table, it has a sprinch, washers and a ball inside.

stretch the spring about 1/2 inch,

that has helped:
-to remove the missing, (poping) at high RPMs while pulling,
-removes poping, missing and blue smoke while reving empty
-produces more power
-all this and more, cuz then it gets enough fuel.

 

i found the problem !!! i replaced the in tank sending unit and it starts (no white smoke) and runs fantastic like it did before!!! i found alot of good ideas on this board on how to check things + all your input and thats what helped me to find the problem i want to thank you guys again !

 

What does the tank sending unit have to do with the starting problem.