My Engine is Misfiring?

Even with all the******** and rough idling its doing? It drive's fine, just that it idling rough and the******** I get when I let of the gas pedal.

Engine has number one cylinder misfire, bad shake. Trouble codes showing are po 301, 180, 1464, and a few others. I have narrowed it down to the number one cylinder fuel injector wiring. No click or strong click from injector, but I have switched known good injectors and still missfires. All the injectors show approx, 8.7 ohms of resistance. I have replaced the connector, no luck. The wiring has 12+ volts on the supply side and 12+ volts on the signal side, while the others show minimal voltage on the signal side with key on. Could this be a possible short? Checked all wiring from injector to computer, it looks fine I ran a continuity test on the number one harness wires which show continuity. Could it be shorting from one of the bad sensors? I am stumped. Any ideas? Thanks

Hi, thanks for the prompt reply. I was thinking of doing something along that line. I actually took that wire off at the harness and did a continuity check at the computer harness, but I believe I was getting a continuity bleep on two wires. What is suppose to be the voltage or signal strength coming off of that computer signal wire terminal? Would any other codes have anything to do with this issue? Such as fuel temperature sensor? Thanks again for your help.

Hi, I cutoff the original signal wire at the PCM and at the harness. No difference. Injector is still not firing. I checked the voltage off of the cut wire and it is still producing 12 Volts at the computer terminal and at the harness with the spliced wire. All the other injectors have no real voltage present off the signal wire with the ignition on. I sure hope it is not the PCM. Any thoughts? Thanks again, Mike

I have replaced the connector with others twice already. Is that correct that I should not have any voltage on that signal wire? If I check it directly off the computer terminal and it reads twelve volts would that not mean an internal computer problem?

I am reading twelve volts when the signal wire is not connected to the injector. I am even reading twelve volts off the ECM terminal with the wiring harness disconnected. I guess I have to bite the bullet and take it into the shop.

Hi guys. Thanks for all your help. I believe I have found the problem. I noticed a little rust at the bottom case of the ECM where it sits on the console floor near the fire wall. I decided to open up the ecu case and found corrosion on the circuit board. One terminal for sure was almost eaten away. I cleaned it up with a soft brush and tried to re-solder it. I will put it all together and try and fire it up tomorrow My fingers are crossed.

Hi Guys, well, bad news I fired it up today with the reworked computer still has the miss and all the codes. I guess the PCM was too far gone. I will try and look for a used one from the wrecker. Will that work as long as the tag matches? I guess I will have to take it to the dealership to have it flashed.

Thanks for all your help guys, much appreciated. Great site with fast responses awesome! Mike