I have an odd miss that occurs in my 93 Ranger XLT 3.0 V6. I acquired the truck about 3 months ago...used. And because the Car Talk guys always ask...it is Cayman Metallic colored.
I've pulled codes twice and get 31, 17 and 21 as active errors. Service done so far includes checking all fluids...changing tranny filter/fluid, changing oil to 5-20W and coolant change. I had my fav shop replace the AC compressor and replace the thermostat. I checked, cleaned the plugs, wires, and rotor...all good.
Truck runs great and gets good mileage. The odd miss occurs when it is really hot out (99-105, W. Tejas) and the AC is on Max. It runs good, just occasionally I feel a miss...very slight, and doesn't affect running performance...still annoying though. I've also noticed this vehicle idles right around 750 rpm consistently...even on a cold start up.
Shouldn't it idle faster at cold startup, then kick down to it's present idle speed after it runs a few minutes? Other vehicles I have owned since the mid-80's have done so.
Two questions: How hard is it to check, clean, change the EGR valve and is that an issue with this generation of Rangers? I know how to do the coolant temp sensor, MAF/MAP and IAC service, but MAF/MAP/IAC don't show up in the codes.
I generally run the green Gus on 86-87 octane gas, which is laced with up to 10% ethanol in my area.
I'm thinkin replace the coolant temp sensor and do a Sea Foam or Techroline fuel system treatment then see if the miss continues. Any constructive input is appreciated.