To start the truck is a 93 p/u with 22re
Since last fall we swapped in a different motor and installed a new fuel pump to get the truck running

Now the truck has to crank about five seconds to start, then you have to give it gas to keep it from dieing for about a 30 sec, after that it will idle

When you drive it after you get it to idle, as soon as it gets to about 2k rpms under some load it has a horrible miss that comes and goes away for several miles

After it clears out the truck runs strong without any miss and idles fine
It only shows a ce when its missing hard under a load

If shut off after its warm it will still run right, but after about an hour the problem is back

We have eliminated the afm, fuel filter, all plugs look similar, changed fuel pressure regulator

Right now were suspecting a loss of fuel pressure from bad check valve or some kind of leak or possibly something to do with the egr

Anyone have any ideas? Each night were trying to eliminate a couple possibilities but could use a nudge in the right direction
Thanks
Clayton