carrier 2500a

[mainmech69]

unit cranks a long time wont start cleaned fuel screen.primed
system,if i crack bleeder it will stay running after it cranks awhile.
fuel cap off.thought may be in pump?

[gravy258]

There's a one way valve between the filter and the pump(brass with a direction arrow), these have a habit of packing up. You can try blowing it out with compressed air or fit a new piece of pipe bypassing it.
If you open the jetstart and it runs for a bit it means its using the fuel return as its feed.

[mainmech69]

installed new check valve and lift prime pump.still takes long time cranking before unit starts.was going to change out top of fuel pump?there is a slide plunger for speed solenoid and shut off sticking some what but freed rod.i have 3 units doing same thing . thanks for any help u can give do not have book on this engine.

[Boss302]

Is the fuel filter plugged up. It will run with a plugged up filter if the jet start is open.

[gravy258]

how many hours have the three done ?
do you change the oil regular ? As old oil tends to gum up the fuel head.
If they've done a heap of hours try adjusting the valve clearances.