2001 4.2 Running Rough
#1
2001 4.2 Running Rough
I have a 01 F150 with a 4.2L V6 with 193,000 miles. Last week while driving home from work, I slowed to turn onto another road and when I started accelerating going through the gears it started shuddering and running really rough like it had a miss. The check engine light began to flash until I let off the gas. I limped it home and put my code reader on it. It gave me a P0304 and P0174 which of course is cylinder 4 misfire and bank 2 lean. Now I put new plug wires on it over a year ago and a new coil pack last August because it had a miss when in a hard pull. The coil fixed it and it's run great since except for having to replace the isolator bolts and gaskets in the plenum. So, I put another set of platinum plugs in it yesterday which would be the second set I have put in it. No improvement so I went back to O'reilly's and exchanged the Borg Warner coil for a new one and I thought sure it would fix it but it didn't. It still runs rough and I still get a P0304 code. Could a plug wire have already gone bad or do I possibly have a bad injector? They have never been replaced. When I pulled the old spark plugs out the #4 plug looked different than all the rest. Anybody have the same experience with theirs?
#2
#3
By the way, I checked the resistance of the #4 injector and it was 12.9 ohms which is below what my Haynes book says. They say it it's supposed to be 13.5 to 19 ohms. I checked a couple more and they were 13.1 ohms. But I also checked the old coil pack secondary resistance and go no reading at all so it may be the test meter. I also wonder about bad gas.
#4
With the motor running at idle I can put my finger and thumb on the #5 and #6 injectors and I can feel them clicking so they are working. But, when I feel of the #4 injector I can't feel anything at all. I don't have an engine stethoscope to listen to them as is said by Haynes but you can feel them working. I guess I'll get a new injector tomorrow. I may have just got clogged up.
#5