I have a 1994 2.3 Ranger that runs rough when the air temp is above 60 -70 degrees. I get codes 172 and 332. I have changed the in tank fuel pump, fuel filter, TPS. Also the MAF sensor, EGR valve, O2 sensor and misc. vacuum lines. Also entire cooling system, including radiator. New Motorcraft spark plugs and wires. When the EGR valve has the vacuum line connected it will not idle at all no mater the temp. Any thoughts?

 

it sounds to me its out of time replace the timin belt they are bad for jumping time let me know if that helps

 

EGR system is only used when engine is under load, like driving up hill or accelerating hard.
So EGR valve's vacuum hose should never have vacuum at idle.

Follow the EGR Valve's vacuum hose back to the EGR modulator(solenoid valve), it will have an electrical connector, the computer activates this valve only when engine is under load.
Unplug the electrical connector, start engine.
Check EGR valve hose for vacuum again, if it still has a vacuum replace EGR modulator, it is stuck open.


On the intake there will be a 2 wire IAT(intake air temp) sensor, gray/red and gray wire.
Computer uses this sensor to fine tune fuel/air mix, colder air is denser so needs more fuel added, warmer air less fuel.
In later models the IAT and MAF sensors were combined, 4 wire MAF, older and 6 wire MAF/IAT, newer.

Gray/red wire should have 5 volts, Gray wire should have less voltage, use a sewing pin to pierce a wire to test voltage.
Colder temp = higher voltage on Gray wire
Warmer temp = lower voltage on Gray wire