[joelava317]

I have a 02' Durango 4.7 4x4, approx 160,000 miles with random misfires. I cannot even get it to idle, will stay on only if I give gas above 1500 RPM, below that it dies out instantly. 2, 7, and 8 seem to be the 3 additional codes of the cylinders misfiring. 2 has been fixed with a new plug and coil. I switched out the plug and coils from 7 and 8 to numbers 3 and 4 but 7 and 8 are still misfiring. Just did that to not force spending money as a test. So it can't be the plugs or coils (although I plan on changing all of them come payday anyway). I have checked and replaced/spliced a few vacuum lines that were either cracked or cracking. Now still showing random misfire code but only the cylinder 7 code along with it...still cannot get it to idle and it is smoking like a chimney out the back. I have also replaced the Crankshaft position sensor with no change.

Someone told me this could just be bad fuel, but if so why only 7 and 8 cylinders are misfiring, wouldn't it be completely random on all 8?

I am in the process of taking out each injector and cleaning them out and replacing the o-rings (do not have the funds to replace all injectors right now).

Any thoughts as to why this is happening, if what I;m doing is correct or any other possible causes? Do I need to go as far as to checking the valves?

Thanks everyone in advance!

 

[tomk]

what did each plug look like when you yanked them?

How's your compression?

 

[joelava317]

Haven't done compression test, plugs looked worn, last owner did not seem to keep up on it...that's why they are all going come payday tomorrow woohoo! The one I did replace I tried in cylinder 7 with no change either.

 

[tomk]

but other than worn, they all looked pretty much the same?

or were some clean, some black, some dry, some wet?

 

[joelava317]

Yeah pretty much the same, black on the threads, rusted at the nut.