I parked my ranger for about a month. Was running great at the time. Had to rebuild transmission in other truck, so was time to put ranger back in the lineup. Right away it's been backfiring, jerking when excellerating and shifting. Fuel mileage was a joke. From 20mpg to 12mpg. Actually when hauling a load it was 6mpg! Sounds like chitty-chitty bang-bang. And is blowing insane amounts of smoke. I tightened the valve cover and the mpg got better. It seems the smoking issue is getting worse it seams. Can bearly maintain mph in 4th gear and 5th isn't even obtainable. I have 2 theories of what is going on. But I really want to hear a second, third or even fourth opinion. 🤔

 

My first guess is fuel filter. Sitting for a month and then reduced performance, poor acceleration, misfires. You can hook up a test gauge to the Schrader valve and look for issues that way. But tbh they are cheap for oem parts id just parts cannon that one.

However if you know the fuel filter is good it won't hurt to check fuel pressure. There's tons of posts here detailing how to look etc. But generally speaking.
Engine off check.
Engine on check.
Under load (2500) check.
Drop load check.

That should check pretty much most things from the tank to the injector..if all that comes back normal then id move on to check the basic tune up items again. Once over.

I didn't see what variant this was exactly so I kept it pretty broad for the fuel injected variants of ranger.


Edit: I just assumed you would know a blown headgasket if it was actual the headgasket. So I kind of skipped that option.

 

Really helps if you include Year of Ranger in the post, 1993 according to profile

Manual or automatic can also help

Assuming 2.3l Lima from the year

On the engine is the Fuel Pressure Regulator(FPR), its on the fuel rail, it has a Vacuum hose attached to it, remove that hose and check it for gasoline, if found replace FPR

1993 has a Check Engine light(CEL), does it work?
Should come on with key on, and then go off when you are cranking the engine to start it
Does it come back on after start up, if so you need to check which Codes are set
1993 is OBD1 interface, so you can read the codes by counting the CEL flashes in Test mode

Google: Ranger OBD1 getting codes using CEL