11996 Mazda B2300 - Bucking at low RPM, rough starting, stalling

Truck has 150000 miles. Very suddenly one day it started bucking violently. Replaced fuel filter, wires, plugs and crankshaft sensor. The bucking became less violent and only happens at low RPM (around 2000 or less).

Replaced the coil but that didn’t seem to make any improvement.

It’s also tough to start, and often when it starts, it will stall when I engage the clutch and move. THEN it is very hard to start, often only starting if I keep the starter kicking it over as it’s trying to start up (just put in a new starter!).

The engine seems strong when it runs. But this problem is driving me nuts! Any help you can offer would be GREATLY appreciated!

How long since a tune-up? any applicable trouble codes? Use a gage and check fuel pressure.

Long delay because of the holidays but… there are no trouble codes, checked the fuel pressure and at idle it’s steady at 32 PSI. Revving brings it to about 34 PSI and then it drops to 30 PSI before coming back to 32 PSI at idle. My manual says it should be 25 to 35 PSI at idle so the pressure seems Ok.

Also, it seems to start better in the morning if I pump the gas pedal.

AND, when it starts the engine seems to really resist and bring the starter to a temporary stop for a moment before continuing again. The new starter I installed still works but I’ve noticed a clicking sound now. I’m not sure if that’s because it’s starting to go or there’s just a loose connection.

Not sure I I have more than one problem here…

Also, new plugs and wires installed within last couple of months. Also a new fuel filter. Those were my first attempts to solve the problem.