HELP! 91 Ranger 4.0 OHV Sputters and stalls off idle/stopped

[Vexarana]

I have a 1991 Ford Ranger Ex-Cab with the 19.6 Gal tank. Never actually had it down below 17 used, which is right about the top of the E on the gauge. So when I was at a quarter of a tank, I wasn't worried about it until it started sputtering one day. Drove it back, parked it, drove it to work the next day fine, and then at lunch it was dead. I put about 1/3 to 1/2 of a gallon in it from a gas can, just enough to get it to the gas station, and filled it up.

It only took 15.3 gallons. And I still have a decent amount left in the gas can. So maybe we're talking 16 gallons total put into it. It reads full, and it didn't read empty when it stalled out.

But now, even with a full tank, it still sputters and tries to stall coming off a stop. It did stall a few times getting it to the gas station, up hills and such, which I felt terrible about, but she still got there fine.

These make me think that my fuel pump is bad, but I didn't find anything in the tech reference section on the main page when I searched for sputtering and stalling. I did find a lot of people talking about the valves being unseated, or a bad coil on a cylinder, or a bad spark plug.

It got me to work fine from the gas station, just tried that sputter/stall trick on me once again, but with 15 gallons pressing down again it was a little better and didn't stall out.

UPDATE:

Last night it drove home from work fine but when I tried to go to the mini-mart it lost power several times in quick succession while driving, just cut out, but recovered, and then stalled when I stopped at a stop sign.

Crank crank crank, finally started. Got it almost to a parking lot, got it up the hill, and then it stalled again on flat ground as I rolled it into a parking spot.

What caused the sudden change? It certainly never stalled before and now it has 20 gallons of fuel in it!

Fuel pump that is in the tank I know I can go in if I take the bed off. Will probably be easier than dropping the ~180 lbs gas tank. Then there is another pump in line? Or is the in-tank the high pressure fuel pump in a 1991.

I'll replace the fuel filter just because, since it will be so accessable. And do plugs/wires as well. Should I check the coils to see if any are going bad? That would just cause one cylinder to not fire, correct? Not misfire and burn out the plug?

EDIT : Looking at some higher performance fuel pumps but none exist for the ranger. Would I be able to convert from an in-tank to an inline pump? Just get different sized fittings, right? I found a Walbro OEM replacement. http://www.fuel-pumps.net/5ca226.html. This repair is looking a lot more affordable than I thought. Just still a pain to get to, it looks like.

 

[alwaysFlOoReD]

My first thought is fuel pump because that's what my problem was. The '91 IS an in-tank, hi-pressure pump. The PO put in a '91 4.0 into my b-II and it seems used the same pump you were looking at in your link to convert from the original low-pressure pump to a hi-pressure pump. He also used rubber line that wasn't meant for gasoline and that deteriorated to the point that the engine was receiving only 20 psi instead of the required 40 psi [I repaired]. There was some modification done to the base of the sending unit and no sock was installed but it's been running for me for three years.
So have you checked your fuel pressure? That would be a good first step before r+r of boxes and tanks. You should be able to borrow a fuel pressure tester from your local parts place under their 'loan-a-tool' program.
Good luck,

Richard

 

[Vexarana]

I check that through the schrader valve, correct? The fuel pressure reader will attach there? Or will I need to attach it in-line after the fuel filter?

 

[hopster]

it ahould screw right on to the schrader valve