Expert: Roland Finston - 12/10/2011

Question
Hi kevin, I own a ´00 dodge caravan with the 3.0 motor in it, a couple of days ago the check engine light came on, I took it to auto shop to get the computer read and the p0302 code came out, it calls a missfire on cylinder 2, I check everything related to it and cleaned the injectors all of them, put back evrithing and test drive it, was fine for o shor time then light came back on, took it to get the reading and this time codes  p0306 and p0206 came out, I know it related to the cylinder 6 so I unpluged it while idling ans didn´t notice any change on the motor poor performance, mesured the ohms, after turning off the engine, on all of the injectors and they are the same specs, mesured the voltage on the cylynder 6 plug and it is oscilating between 7 and 9 volts, is this fluctuation normal? coul you please guide me to what to check next?

Answer
Hi Luis,
The injector has a 12V constant wire (dark green/orange) and then a 'driver' wire (brown/dark blue) which oscillates between 12v (injector closed) and momentary 0v (when activated) by the pcm. That. when the engine is running, might 'look' like a varying voltage on your meter because of its slow response to such rapid pulsing. Check the resistance across the injector with its plug removed to see if it is a very few ohms, and also check the driver wire to pin 14 of the pcm for a solid connection. If the connection is good, amd the reading is more than 10 ohms or less than 1 ohm, then perhaps the injector is faulty.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been referred by Kevin. Pleae 'rate' may answer. Thank you