I have a 96 Ford Ranger XLT Supercab 2.3L 5 Speed and it is having an issue idling. When idling low(500-1000 rpm's) it feels like it is missing terribly and struggling to stay running. Once you give it some gas, with no hesitation it clears up around the 2000 RPM range and runs fine. Occasionally when driving, the idle will hang anywhere from 2000-3000 RPM's. If i unplug the MAF Sensor it idles helps it, but doesn't fix it. I have replaced the MAF twice, Thinking the first one i got may have been bad, within the last week. I have also done Plugs, Plug Wires, and Coil Packs in the last week. Replaced the IAC yesterday and I am running out of ideas. This all started right after i had the heat shield for the cat cut the rest of the way off, since it was about to fall off anyways, but i wouldnt think that would have a whole lot to do with it. Sprayed brakleen around the intake to check for vacuum leaks and did not find anything. If I unplug the TPS sensor it doesn't change anything, so that was my next option. and to remove my cold air intake to clean the butterfly on the throttle body. Please help!

P.s. It threw the CEL last night while i was on lunch at work. This truck has a crack in the fuel tank which cause the Evap purge solenoid to throw a code regularly(has done this every since i have had the truck) but I am fixing to go read it and will let y'all know what it says.

 

At idle the computer runs cylinders rich, but based on air flow(MAF) and long term fuel trim(data), if you unplug the MAF the computer will switch to "safe mode/limp home mode", pre-set fuel mix data programmed when truck was built is used, this prevents MAF sensor failure from disabling engine.

I would check vacuum line on Fuel Pressure Regulator, you could have some fuel leaking into intake from this vacuum line at idle(when vacuum is high) causing engine to flood a bit, as you increase RPMs vacuum drops and extra fuel slows and is burned up easier so it stops missing.

 

Where is the fuel pressure regulator located? Where does this vacuum line attach to the intake? And If I do have gas dripping into the intake from this line what do I need to do to fix that? I read the codes and it threw and intermittent TPS code(which may have been cause by me unplugging tps earlier in the day. and the usual evaporated purge solenoid code. But the CEL did not come on until several hours later. Should I still go ahead and replace TPS If I have already purchased one?

 

There are 2 fuel lines on the engine, the line from the fuel pump and Return line back to the fuel tank.
Fuel pressure regulator is where the Return line attaches and you will see it's vacuum hose.

If there is fuel in that vacuum hose then replace regulator.

If you already bought a new TPS then replace the old one, make sure you unhook the battery when replacing anything, this is extremely important on newer vehicles with computers and electronics.
Throttle response may act "funny" for the first few restarts and driving, that is normal as the computer "learns" the new TPS's voltage settings.