Need help with Dodge pick-up

Discussion in 'Trucks and Trailers' started by I MOW ALONE, Jan 10, 2003.


    I MOW ALONE LawnSite Bronze Member
    Messages: 1,964


    I need help with my 1993 Dodge D150. It has a 5.2 litre, its MPI. The motor only has 25,000 miles since rebuild. The problem I am having is I'm getting back-firing through the exhaust. I've replaced the fuel filter, cap, rotor, pick-up coil, and the coil, plugs, wires. I also have replaced the crank sensor because the truck kept dying and then wouldn't start, traced that back to the crank sensor, replaced it solved that problem, but still have the back-fire. I checked fuel pressure it should be 35 - 45 psi, I'm getting 30 which I know is a little bit low but when I pull the vacuum line on the fuel pressure regualtor, I'm getting 40 psi. Still has the back-fire. So I feel that it is not a fuel pressure problem. The truck does have a cam sensor, but I am not sure if that could be my problem or not. Any help would be greatly appreciated.

  2. E-man

    E-man LawnSite Member
    from PA
    Messages: 136

    Have you checked or replaced the EGR
    Also if it has an air pump the problem could be in there. I had a ford that had the valve or diafram (cant remember what is was) in the air pump go bad and it back fired all the time.
  3. My first thought was timming but that not even listed in the trouble shooting guide.

    Heres a copy of the page from my dodge book.

    dodge book.jpg
  4. Barkleymut

    Barkleymut LawnSite Bronze Member
    Messages: 1,117

    A new PCV may do the trick.

    I MOW ALONE LawnSite Bronze Member
    Messages: 1,964

    thanks for the responses they are all good possibillitys how would i check the air pump and the egr what should i look for and i will replace pcv see what happens
  6. E-man

    E-man LawnSite Member
    from PA
    Messages: 136

    To check the air pump take off the two hoses that go into it , drive the truck and if it dont baqckfire thats probly the problem.As for the egr the best way without some kind of emmisions test is to try a new one.You can also check the pcv by taking it out and shake it, if it rattles its fine but if it dont then its clogged.
    I hope this helps a little ..good luck
  7. nokomower

    nokomower LawnSite Member
    Messages: 6

    Hi Dave

    I have been a Dodge Auto
    tech for 15 years and from what I gather your backfire is due to your distributor housing that holds the pick up coil need to be set in phase with the crankshaft to provide the proper timing from the computer to fire the plugs and injectors. I would advise taking it back to whoever rebuilt the motor to check the distributor sync. Also, there was a recall on distributor drive gears prematurely wearing out if there is no excessive play on the distributor drive shaft to cam then more than likely you are ok there! BOTTOM LINE IS the shop that did the rebuild should stand behind their work and correct the problem, or point you in the right direction.
    Good Luck

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