1994 Ford Ranger 2.3 running rough

[Jimmyjames]

I have a 1994 Ranger 2.3l that just started running very rough. It will start and idle but has no power under acceleration and jerks and bucks badly. The exhaust smells like fuel but has no color or excessive smoke. The truck is a 5speed manual and has 136K on it.

I have replaced the fuel filter, air filter, checked the spark plugs/wires (which were replaced within the last 10K), and the coil packs tested fine. I checked the MAF and it was very clean looked almost new even though I have never replaced it. I did notice in the past that the truck would "jerk" slightly when going up a hill but that dissappered when I changed the plugs and wires. This curent situataion hapened suddenly all at once rendering the truck undriveable.

Any advice would be appreciated!

Thanks

 

[pinballer]

I have a 1994 Ranger 2.3l that just started running very rough. It will start and idle but has no power under acceleration and jerks and bucks badly. The exhaust smells like fuel but has no color or excessive smoke. The truck is a 5speed manual and has 136K on it.

I have replaced the fuel filter, air filter, checked the spark plugs/wires (which were replaced within the last 10K), and the coil packs tested fine. I checked the MAF and it was very clean looked almost new even though I have never replaced it. I did notice in the past that the truck would "jerk" slightly when going up a hill but that dissappered when I changed the plugs and wires. This curent situataion hapened suddenly all at once rendering the truck undriveable.

Any advice would be appreciated!

Thanks

my truck is doing the exact same thing. What did your problem turn out to be?

thanks

 

[scotts90ranger]

I doubt they will answer, as they only have one post from just over 2 years ago...

That said, if your exhaust smells like fuel and the change happened suddenly like theirs did there's only a few possible causes:
-fuel pressure regulator failed, locate the regulator (at the front end of the fuel rail, has a vacuum line going to it) then pull the vacuum line off, start the engine or just cycle the key, if fuel comes out of the vacuum line you just took off, replace the regulator.
-a fuel injector is stuck open, it got something in it, take out the 4 passenger side spark plugs (since they're way easier to get out than the drivers side) and see if any of the spark plugs are wet with fuel, if they are either take them all out and have them serviced (should be about $75 locally, I had it done a couple years ago) or replace the bad injector
-before replacing the injector, maybe check the wires to the injectors first to make sure one of the control wires isn't shorted to ground, all 4 injectors should have a common power wire then there'll be either 2 or 4 ground wires that the computer uses to open the injectors (2 if it's '94 or older non California, 4 if it's '94 or newer California model, they were batch fire until that switch, in non cali they switched in '95, you can tell by if it has a cam sensor behind the auxiliary pulley)
-another possibility is if the oxygen sensor is bad and seeing 0 voltage which would typically be from a damaged sensor, a bad power or ground to it's heater circuit, or an open circuit on the signal side. The easiest way to test this assuming it is OBD-1 not OBD-2 is to disconnect the battery for a few minutes then restart the engine, if it runs better for a couple minutes until it warms up, there's something in the closed loop system adding fuel until it gets slobbery... Yours is a '97, so it's OBD2, get the codes pulled then clear the fuel adapts with the tool to do the same thing.

After typing all that out, the ABSOLUTE BEST AND SHOULD BE YOUR ONLY FIRST STEP is to check for trouble codes, Autozone will do it for you for free, start by looking into those issues before throwing money at things that aren't the problem!