4.0 woes

[AngryLepercon]

Bought a 99 xlt 4.0l that needed work. Put heads on it because had a misfire in cylinders 3 and 5. Turns out gasket blown and heads were cracked. Ran fine for 2 years. Started to idle rough like really rough again and loss of power. CEL came on and a week later started flashing pulled codes for misfire in cylinders 5,6,and 3. In that order with no other codes if it means anything. I have narrowed it down to plugs and wires (6 months old) bad coil pack, vacuum leak, or fuel filter. Any other ideas on what it could be. I'm willing to try any route that doesn't involve pulling the heads again. I need to get this thing fixed. Tired of paying for diesel in my 08 lol. Any help would be appreciated.

 

[nightcop]

well you might check the compression to see if the heads are cracked or bad head gasket. but i just did a motor swap with a 4.0 into my 88 ranger. ran good during the break in. then it died thought i had a bad coil but it turned out to be a bad EEC. i replaced it first with one from a junk yard. truck ran great so i got a new EEC and kept the junk yard one for a spare. might be something to look it.

 

[AngryLepercon]

Thanks for the info. I hope its not that but ill check it out anyway gonna start small with a fuel filter and a coil. Hopefully get them on tonight or tomorrow night. I freaking hope its the coil.

 

[AngryLepercon]

Update:

Fuel filter, coil, and sea foam done drove it all day yesterday. CEL came on.... forget the actual code number but it was too lean bank 1 with no misfire codes. Gonna double check the vacuum lines and clean the MAF sensor. Any other ideas? Still runs a little rough but no where near as bad as it was.

 

[AngryLepercon]

Update on an update well I tore into the top half of the motor. Replaced all injectors, as well as upper and lower intake gaskets. Also flushed the coolant added water for a test drive and everything seems back to normal. I do believe the issue was in the gaskets as the lower was split and there was a redish/brown stain around the top of cylinder 5. Will update again if problem comes back

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