2 coil packs with wires which have all been replaced also. After dropping $2000 on a new engine Im at a loss on what this could be. On the plus side I guess she isnt throwing the 171 and 174 codes now lol.

 

Ok so u need to inspect ur wireing harness good. Cause I'm sure u have switch coils on both side an it still misses on 4 an I'm sure u don have the same injector in there as before. So u need to check u harness that plugs into the coil pack and trace back wires. Same as for the injector wires. U may be able to pick a wire harness from a junk yard for not much. If u can find a good one. It's just something I wouldn't rule out. Cause I mean u have changed everything......

 

How do you check that does anyone know? Nothing in my book..

 

U are just going to have to follow wires back. Look for rubbed or necked spots in the wiring. Where they have rubbed together. U could remove the wiring harness from the truck. Not to hard to do. But that would be my next move. Inspect it are just replace it. Depends on cost.

 

I will check that out. Just out of curiousity though if the computer was bad wouldn't it cause more than just this one cylinder misfiring?

 

Also if the wiring harness was bad wouldn't it affect all the cylinders on that coil pack instead of just one...?

 

have you replaced wires? my 1998 4.6 picked up a bad miss fire and it ended up being a bad plug wire

 

That's where I'm not sure. But it would never hurt to pull the harness off and give it a good lookin over. It's easy to do and wouldn't cost u any money if u done it urself. I haven't messed with many 4.6s with the 2 big coils up front.

 

If u pull ur plug wire off cyl. 4 and lay it across something and poke a screwdriver up in it ir maybe snap a old spark plug in it.... Dies it fire when it's running?

 

The plug wires have about 2000 miles on then now. Replaced them when all this originally started. I have since driven to Reno for the new engine and now back in Colorado Springs. Headed east tomorrow as I have to pick my son up and have no choice in the matter.

I looked at the connector but was so tired I didn't go deep into the wiring. I don't know **** about electrical stuff and honestly it scares me a little. After all my chances of getting electrocuted are greater than winning the lottery lol. Plan on doing that first thing in the morning though also gonna start it when it's dark to see if I can see a bad wire maybe...

At this point I have no choice but to drive it back to Carolina. My main concern is I don't screw the new engine up and the fuel consumption as I am way low on funds after all this and think my son and I might be stranded in Oklahoma or Tennessee somewhere unfortunately. Goo g to the pawn shop tomorrow to see how much extra I can get as its only getting 14 mpg on the highway right now and that's running at 2300 rpms or so where it isn't a noticeable miss compared to at 1500 rpms.