misfire

[Matt Murphy]

I am having a trouble misfire when idle.... last week i put on a 3" body lift and did it myself so im sure i did something wrong but whats happening is i have a bad misfire with to autozone out it on the computer and it just showed mult. misfires so i thought it was the coil so i replaced it and then i got a fireing pen andchecked my spark plug wires all three on the driver sides are firing fine the passenager side none are firing so i went out got new plugs and wires still misfiring.... is there a body ground or something like that. that could have came unplug and something i forgot to hook up causeing this?

 

[Todd Z]

The ST coil fires 2 cylinders at a time, so you should have 2 or 4 or 6 plugs not working..



I would check the wiring that plugs into the coil and make sure the computer is getting the signal to the coil...

You may have broken a wire in that harness...



Todd Z

 

[Matt Murphy]

i hold the firing pen there for about 2 minutes not one fire at all

 

[Matt Murphy]

what would be a good way to check the wires in the harness?

 

[Matt Murphy]

i just checks my spark plug wires again and here is what it is doing... i check the drivers side plugs first.. all three wires never stops firing... then i move to the passengers side i get no firing at all on the wires i move up to the tabs on the coil and they are barely firing... what could this be?

 

[Todd Z]

did you re install the little black resistor that bolts to the coil on the front right screw ???



poke the wires that are feeding the coil, those tell it to fire, 1 is ground the other 3 fire 2 of the plugs at the same time...



I think you have a broken ground or wire in a harness some where..



Todd Z

 

[Matt Murphy]

yes i did put the black resistor on... i thinking it may be ground also is there a body ground that could be causeing this and maybe i forgot to put it back on when i did the lift?

 

[Todd Z]

since it is only 1 side of the coil I would say no.... Remove the coil and check the plug and wires in that harness, maybe it broke, is burnt on the exhaust, Stretched, something...



Todd Z

 

[Scott Heckler]

There is two body grounds that get disconneted under the truck on each side about at the front doors. Did you connect them both again?

Also when you put on the upgraded coil did you replace the connector with the one with longer wires. The OEM connector gets pulled pretty tight. That harness may have hung up when you lifted the body.

 

[Matt Murphy]

oh ok i will check on them tomorrow thanks for all of yalls help