Page 2 of 2 FirstFirst 12
Results 26 to 29 of 29

Thread: Need some help, Backfires when given gas.

  1. #26

    Array
    Status
    Offline
    Join Date
    06-15-2014
    Posts
    6,059
    Location

    Adelaide, South Australia
    Vehicle

    1985 Mitsubishi L200
    Engine

    G63B
    Make sure that accelerator pump in the carb is working. This is a symptom that it's not getting the little extra boost of fuel off the mark. But even if you go hard open on the throttle, the carb won't be able to keep up with the sudden increase in vacuum. The Mikuni is a slug and you have to 'feel' your way into the power curve. Give my tune method a try (I know you are subject to Cali EPA crap) but you can always re-set it when it comes to inspection time. If you can get the ignition to follow a similar curve to the throttle butterflies opening, you'll unearth some useful midrange power and improve your highway cruising top speed.

    Well done to you for persevering. It sucks when you keep hitting a wall and can't get around it. The biggest issue you had was the coil wiring and the distributor being out a tooth. It didn't help that a workshop couldn't even hook up the fuel lines properly and took a short cut just so it would run.

  2. #27

    Array
    Status
    Offline
    Join Date
    10-23-2015
    Posts
    48
    Location

    California
    Vehicle

    1986 Dodge D-50
    Engine

    G63B
    Thank you!

    I have been reading your advice and by luck I found this guys thread as well http://www.mightyram50.net/vbulletin...-for-smog-Help.

    I think my choke needs to be adjusted a tad, it's closed up tight when sitting and has some tension on it that a "light tap" can't easily open it when cold.

    I'll see what I can do to it tomorrow.

    Thanks again for your help!

  3. #28

    Array
    Status
    Offline
    Join Date
    10-23-2015
    Posts
    48
    Location

    California
    Vehicle

    1986 Dodge D-50
    Engine

    G63B
    Quote Originally Posted by geezer101 View Post
    The line that is now hooked from the pump to the return hose is meant to feed into the forward facing fuel hose barb.
    Well, was running for a short time fine but still had a flat spot. Ended up taking it apart and found a diagram for the (vent system??? 3 screws holding on a solenoid of some sort towards the valve cover side) was cracked and the cast piece was in cracked in half. That was allowing fuel to go from the bowl, straight into the vacuum. Prob explains why I was getting a consistent 250 miles per tank. Got a rebuilt crab and hope for the best on it. But yeah that gasket looked like it wasn't replaced, and when the cast piece was cracked when it was rebuilt, they prob didn't bother doing anything and put it back broken.

    For the accelerator pump, did you mean the fuel pump hose gets connected to the "forward facing" fuel barb on the right side or the one in the front, to me they are kinda both can be forward facing lol... Ran the same hooked up either way it seemed on the old carb, but slightly better, Sorry, I just don't want to blow anything on the "new" one.

    Just wanted to share what I found out.

    Thanks.

  4. #29

    Array
    Status
    Offline
    Join Date
    06-15-2014
    Posts
    6,059
    Location

    Adelaide, South Australia
    Vehicle

    1985 Mitsubishi L200
    Engine

    G63B
    The accelerator enrichment pump is the square block on the side of the carb with a fuel line in and out. Top barb is from the fuel pump, bottom barb goes to the return line. The primary and secondary fuel feed lines (from the pump) are different diameters (primary/fuel bowl line is obviously the bigger diameter hose). It wn't kill the carb but the engine won't run right if they're swapped.
    support the forum that supports you - join and donate to MightyRam50.Net today! donations unlock the edit function

Page 2 of 2 FirstFirst 12

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •