Random Misfire after changing plugs, wires, cap and rotor
^^^ Why remove the fuel line? Just remove the fuel pump relay from the power distribution box under the hood and unplug the 12v power supply to the ign coil, then run your comp test. Remember to keep the skinny peddle at WOT when testing comp.
Okay thanks that makes much more sense. Just got the first one done and it was at 122 and now I am going to do the rest and let you guys know. Sorry if the questions are frustrating but I feel the pain doing this in the dark in Wisconsin =P
Okay this is what I got, not sure why the first cylinder was so high but hopefully this will help clear stuff up.
1 - 122
2 - 93
3 - 95
4 - 100
5 - 75
6 - 90
7 - 82
8 - 100
They seem to be a little over the place, but I don't think I did anything wrong, just put it in and cranked it. I had to do it by myself so there was a lot going back and fourth
Also, before I did this I ran the truck without the rear 02 plugged in and it ran the same. Should the next step be testing to see if the plugs on the misfiring cylinders are actually firing?
1 - 122
2 - 93
3 - 95
4 - 100
5 - 75
6 - 90
7 - 82
8 - 100
They seem to be a little over the place, but I don't think I did anything wrong, just put it in and cranked it. I had to do it by myself so there was a lot going back and fourth
Also, before I did this I ran the truck without the rear 02 plugged in and it ran the same. Should the next step be testing to see if the plugs on the misfiring cylinders are actually firing?
Rebuild time.
Dodge states 100PSI is minimum.... and you have 6 that don't qualify. Another factor is, even if they were all at least at minimum, most manufacturers only allow a maximum 25% difference from highest, to lowest, and again, yours doesn't pass that test either. Leaving off the number one cylinder, you would barely squeak by.... but..... That is one tired engine. Time for a new one, or, a refresher for that one.
Dodge states 100PSI is minimum.... and you have 6 that don't qualify. Another factor is, even if they were all at least at minimum, most manufacturers only allow a maximum 25% difference from highest, to lowest, and again, yours doesn't pass that test either. Leaving off the number one cylinder, you would barely squeak by.... but..... That is one tired engine. Time for a new one, or, a refresher for that one.
How long was I supposed to crank for? I did like ten or so then went and checked and then did a few more times of that and it always went up. But the first one was the only one to jump up. Also after the first one the compression checker was stuck and the metal part was spinning within the threaded part and I had to use a screwdriver to push it all together to break it loose and get it out. Could this have been a problem? I hope I did that whole check correctly.
One final question, if my truck has been running perfectly how could it have just started running like crap and misfiring after I stopped it for 5 minutes?
This does suck though. Wish this thing could have lasted me my final semester
One final question, if my truck has been running perfectly how could it have just started running like crap and misfiring after I stopped it for 5 minutes?
This does suck though. Wish this thing could have lasted me my final semester
Before completely scrapping that engine or throwing a rebuild at it I would double check those numbers just to make sure, and make sure your compression gauge actually holds the pressure from cranking. My crappy gauge from Advance would leak until I lubricated the little o-ring in the gauge.
You could feel and hear the air leaving the gauge as my buddy cranked the truck.
You could feel and hear the air leaving the gauge as my buddy cranked the truck.
Okay, well I will get my roommate to help me possibly this weekend. I got this one from autozone and it did not seem as good as one I used from a mechanic in the past. Should I return it and maybe rent one from O'Reilly's?
It also fires up right away and idles consistently like normal and when I drive it I can feel it still has some it just is chugging
It also fires up right away and idles consistently like normal and when I drive it I can feel it still has some it just is chugging
Last edited by schmidtp; Jan 7, 2013 at 10:06 PM.
A new comp gauge test is cheap go get a new one and start over. When I do my comp test its a turn over the motor of three to four times that's it. If you are not 100% sure how to do a comp test have a read here. Best of luck hope the second time improves for you.
http://www.gregsengine.com/cylinder-...n-testing.html
http://www.gregsengine.com/cylinder-...n-testing.html










