Mercruiser 140 3.0 Runs rough and Fuel Pump Questions?

drewshep

Cadet
Joined
Mar 7, 2016
Messages
20
So I have an 84 Mercruiser 140 3.0 that I just did a lot of work on and now she sometimes runs ok under 3k rpms and sometimes won't run for more than 10 seconds. I threw an electric fuel pump on her after the original went bad to save some money and now I think she isn't getting enough fuel with it, so I bought a marine mechanical pump but the cam lifter thingy isn't in the same position as my original pump, it's more straight, then up. My question is will this new pump still work? And does anyone have suggestions for my fuel issue? The picture with the pump upside down is what my original one looks like. and the other one is the pump I just bought.
 

Attachments

  • photo274921.jpg
    photo274921.jpg
    233.5 KB · Views: 0
  • photo274922.jpg
    photo274922.jpg
    209.6 KB · Views: 0

savetexomabeaches

Chief Petty Officer
Joined
Jul 4, 2013
Messages
420
If you unscrew that bottom part, there is a filter inside of there. Also, there is a filter inside of the line where it meets the carb. If the fuel pump is bad, a clear hose should be hooked to it and to the carb and you'll see fuel flowing through that clear hose.
 

drewshep

Cadet
Joined
Mar 7, 2016
Messages
20
If you unscrew that bottom part, there is a filter inside of there. Also, there is a filter inside of the line where it meets the carb. If the fuel pump is bad, a clear hose should be hooked to it and to the carb and you'll see fuel flowing through that clear hose.
Well one problem is that my overflow line is not clear its a black fuel line and all my lines are clean along with the filter in the carb and water separator.?
 
Top