I have a 1994 Ranger with a 2.3 5 sp 2wd. When I go full throttle (entering a highway) by the time I reach 45 mph the engine starts bogging down, missing, and finally stalling. I do not have this problem any other time (runs fine in city driving). I checked computer codes and replaced o2 sensor. I have replaced plugs, wires, air filter. Still no help. My hair is getting greyer on this one, and I can not afford dealer prices. Anybody have any suggestions what else I might look for...!!! ????? Thanks...

 

Welcome to FTE!
In the Power Distribution Box, which is in the engine compartment, there's a relay for A/C & WOT (wide open throttle). That's where I'd start looking.
Try calling up the dealer & ask how much this relay costs.
Hopefully, another member will pipe up to explain how to test this system because I don't have that info.
Try posting in the Ranger forum &/or the electrical forum to see what comes back.
AL.

 

Fuel filter. You are asking for heavy fuel flow for a semi-extended period of time, and the filter could be flowing enough for about every other occasion, but not for full throttle over a few seconds duration. If the relay noted above is cutting out, you'd notice a chug effect as the A/C was toggled off and on. I don't think it would be enough to produce what you described. You can duplicate it's function by turning the A/C on and off manually as you accelerate, or for that matter, leaving the A/C off to check if it is really causing any noticeable effects.

I'd check with a pressure gauge taped to the windshield before replacing parts. But, I'd check with the gauge before doing the fuel filter also... that would rule out the filter, the pump, the pickup sock and the pressure regulator.
tom

 

I concur, that sounds like the symptoms associated with a clogged fuel filter. It is cheap and easy to replace on a Ranger, and as it sounds like you've tried just about everything else, I'm almost willing to bet that's where the problem lies.

Bart

 

Changed the fuel filter and checked the fuel pressure. OK there. Still dies only under wide open throttle. Dealford may have something I can check out...

 

The problem turned out to be the mass airflow sensor. Was sensing wrong forcing to much fuel at wide open throttle killing engine.