Hey guys, new to this so hope I get it right.
2003 ranger v6 3.0
Engine has "multiple misfires" from the gizmo AutoZone hooks up to read codes. Replaced fuel filter, plugs, wires, ignition coil, and air filter in the last week. Sprayed brake cleaner around mainifold with no significant RPM changes. Ran two bottles of injector cleaner through. Still misfiring.
CEL on at all times but flashes when I accelerate or give it a little gas to get up a hill.
Any suggestions?

 

Did you get any particular cyl misfire codes ?
Did you hear any chirping noises from the engine at any time?When did the problem first appear?

 

P 0300. No chirping noises.
About two weeks ago.
Seems to bog down a little more in over drive than drive, too.

 

Look closely at the coil for cracks or carbon traces where spark could be jumping.

 

No cracks or arcing that I can see.

 

If you have someone hold the foot brake on then place the vehicle in drive and give it a little gas to load the ign syst. Sometimes you can hear the spark jumping to ground and if it is external you might even see it if it is dark enough.

 

I'll give it a try. It would be coming from the ignition coil? The spark plug wires, since insulated shouldn't have anything to do with the misfires if the wires are in close proximity of each other, correct?

 

It is always better to keep them separated as much as is reasonably possible. If the wires are original it could be time to replace them.

 

I have a 2003 Ranger with many of same symptoms
Check out the catalytic converters all five of them-had to replace the Y Pipe and rear converter
Also check and see if the timing chain is loose mine was and had to be tightened
I got all the plugs,coils and wires replaced first and the truck still had no power
Good luck