I have a 2002 Ford Ranger 3.0. It has a very rough idle and is on the verge of dying. A bit of back story it was driving fine and the upper radiator hose came off soaked the motor and it dyed it was towed home. Replaced the hose now it has a very rough idle and is on the verge of dying give it a little gas around 2000 rpm it runs smooth as glass. I have replaced plugs, plug wires and the coil pack checked for vacuum leaks with smoke and cans of starting fluid. I did a compression check all cylinders are between 130 and 140. It has pending codes p0300 p0305 and p0306. Some live data at idle 642rpm
Short term fuel trim bank 1 0.8
Long term fuel trim bank 1 18.8
Short term fuel trim bank 2 24.2
Long term fuel trim bank 2 11.7
Mass air flow .01 lb/s
O2 sensor bank 1 sensor 1 .075v
O2 sensor bank 1 sensor 2 .905v
O2 sensor bank 2 sensor 1 .045v
O2 sensor bank 2 sensor 2 .645
Live data at 1639 rpm
Short term fuel trim bank 1 4.7
Long term fuel trim bank 1 2.3
Short term fuel trim bank 2 -1.6
Long term fuel trim bank 2 -0.8
Mass air flow 0.04 lb/s
If there is any other data you need I can try to get it for you.
I’m at a loss..
Any help you can give would be much appreciated. This is my Dads daily driver.

 

Welcome to the forum

Check your coil pack spark plug wiring, they are in Matched Pairs, there are only 3 coils in the coil pack NOT 6
[3 4]
[2 6]
[1 5]

So 3 and 4 must be together on the same coil, same for 2/6 and 1/5
Easy to miswire the 5 6 4 side of coil pack

Also check other end of spark plug wires, easy to get wires crossed, i.e. 4 and 5 reversed or 1 and 2
Just follow each wire to its cylinder
And do it 3 times, lol
I have chased my tail on miswired firing order more times than I would care to admit, KNOWING it WAS RIGHT!!! would have bet my life on it, I would have DIED, lol
Ford cylinders are numbered this way
3 6
2 5
1 4
front



IAC(idle air control) valve
Computer uses this valve to set engine idle RPMs
It is a 2 wire solenoid, that holds an air valve open to set RPMs
Higher RPMs with cold engine and then lower RPMs as engine warms up
Its accurate +/- 4 RPMs so very accurate system
This wouldn't cause misfires, just stalling if it wasn't working

The misfire codes means the Cam sensor is working, Cam sensor can be a common failure on the 3.0l engine which can cause rough running but usually would cause a different code

Fuel injectors and fuel pressure
You can put a can of Seafoam or similar injector cleaner in the gas tank, it will clean dirty injector tips that will cause rough idles because fuel is "dripping" from the tips instead of "spraying" from the tips, at higher RPMs the the injectors are open longer so fuel will spray again
A dirty fuel filter can cause lower fuel pressure , but usually doesn't effect idle, its more likely to effect engine at highway speeds, higher fuel demand

 

I will check plug wires in the morning and put some sea foam in it