Why won't it stay running?

Dirty or damaged mass air flow sensor ! Disconnect the sensor an see if it will keep running . Also check the fuel pressure regulator for leaking . What make , model an year vehicle , size engine ?

Has anyone checked base fuel pressure with a gauge ?

did you give it a tune up change plugs fuel filter

Sound like bad valve ckeck the compression on the engine ,next the
tempature sensor on the motor.Good Luck.

i was told that some rangers have a govner or sensor that won't allow you to go over 3,ooo rmp at a idle,it will make it run rough and backfire,it' to keep you from blowing up your motor

all code readers will retrieve information stored while in the on position --doesnt need to be running ---when you rehook up scanner either resubmit or edit request with codes

Really sounds like a vacuum leak. Lean code could still be accurate. Screaming idle usually means air is getting into engine. Ruptured EGR diaphragm would vent air. Brake booster could vent air. A lot of air will show lean mix.

You may have to use different methods to test vacuum. Some use vacuum gauge to test egr and lines which dead end into solenoids. Other tests use water spray or propane gas to draw in and change rpm. You are at a disadvantage if engine does not run.

Crankshaft sensor helps set fuel volume for given rpm. Might not be counting all the rpm's, but would not account for fast idle.

check ur distributer cap

sounds like a timing chain or timing belt if i had to guess,but unless you are a car buff something that old is not worth repairing.

I have the same problem few days ago, and still didn't find any solution. Can any one please help?????3