1991 backfiring problems

[ikamcire]

Hello, Im new to forum post, but I end up here a lot when Googling problems with my 1991 Explorer.

Anyway, I was getting below average fuel economy and decided it was time for a tune up, I purchased new plugs ( Bosch Iridium #9655 ) and wires. When installing the new ones I crossed numbers 4 and 6 , when trying to start my rig a large back fire occurred and my already worn out muffler detached from the front of the exhaust. After troubleshooting the problem and getting the correct plug wire order(after two more failed attempts). Though now rather than a smooth ride like I had anticipated I lost alot of power and it back fires anytime I go up a steep hill or exceed 2500 rpms (while in drive not park or neutral).

I consulted a friend of mine and he said maybe the gaps were bad, so i set them .054 as i found suggested elsewhere in this forum, gained some power but it still backfires and when I took it on the highway to see how it handled higher speeds I hit 50mph with little trouble and quite a few back fires but once I put it in Overdrive the vehicle began to vibrate like I was driving over a gravel road or the safety bumps on the sides of the highway.

Did my crossed wires caused cylinder problems? Is the missing muffler affecting engine pressure? Is my automatic transmission going out?
Or could it be something I haven't thought of?

 

[2stroke]

Sounds like you simply still have wires in the wrong order. How do I know? I've done it... a lot. If it ran decent before you did this, its certainly the wires.

 

[ikamcire]

so you were right I thought the firing order was:

Engine:
3 6
2 5
1 4
Coil Pack:
3 4
2 5
1 6
But the coil pack is actually:
3 4
2 6
1 5

I looked at a diagram and even wrote it down wrong. Thanks sometimes you just need someone to tell you to look again.

 

[2stroke]

No problem, like I said, I've done it more times than I care to remember.