Ok i have a 92 with a 3.9 and have read posts and FAQ's for hours over the past couple of months and am looking for what to try next. History first, I bought the truck after driving it once with no issues and drove it home, next time I started it it idled kinda high for second then sputtered and died I thought nothing of it and just started it again with no issues well needless to say I have the intermittent issue known to these trucks I started by doing basic tune-up stuff cap,rotor,plugs,wires the first time it happened, before researching anything, since reading this site I have replaced the pickup in the distrbutor, and found the 3 red and white wires spliced to the single red and white wire were a little corroded i stripped them back and soldered them all together, I have read and heard too much to sort out so I guess my question is where should I go next? My thoughts are TPS, fuel pump, coil, ECU, whole distributor, junk yard(last resort) please somebody point me in the right direction. I can start the truck 10 times and it will start perfect 5 times, I can drive it ten times and 5 times it will "throw its fit" usually when I first tip in to the throttle from being off the throttle and this is completely random hot, cold outside, just started up to been driving all day. If I keep it running when it is acting up by feathering the throttle or holding it to the floor it backfire through the throttle body and spit and pop until I either shut it off and restart or sometimes it just clears up on its own. Thank for any help, John!

 

Tons of possibilities. There are 2 main power feed wire splices that need to be checked. It could be just a bad wire anywhere in the truck. By backfire makes me think you have a timing issue. Or spark plug wires crossed. Good luck!

 

^^X2

I'm thinking the same thing your engine timing is out somehow.

My jeep backfired thru the intake once because when I replaced the cam sensor. I accidently put the distributor 180 degrees out.

 

Like I was saying it runs perfect one trip starts fine runs fine this is intermittent so is it possible for the timing to change and then fix itself and today i stripped the harness under the relay box and redid all the splices within a foot of it 3 red/white into one, two blu/white into one, two purple into one, pulled on all the fusible links to check them, swapped the relays around, knocked on the ecu while running, wiggled and yanked on just about every wire I could get my hands on. Start it once runs fine idle goes to about 1200 settles back to normal, when it is going to act up it goes to about 1800 on startup and thats how I know its doing it so I can give it some pedal and it will just backfire and pop and stutter until i shut it off and restart it or it just decides to clear up on its own.

 

Main power splices is one of them the 3 red/whites into one?

 

The wires you re-soldered, are they the ones that all join together under the fuse box?

Also did you put the distributor cap back on right? My car, I put it on 180 deg on wrong. I would also check to make sure the plug wires are in correct as Az93DKota said.

 

Another thought... my old Ramcharger had the same issue, turned out it was the ECU. Not saying run out and buy a new one, there may be a way to test the ECU. Are you getting any codes or check engine light?

 

Is it possible that the distributor is moving?

 

It should clip down and not move but it is possible. Maybe he didn't get it clipped in completely? Is there arcing inside the new cap? Or moisture?

 

The problem has not changed with anything I have done also I have the screw down cap not the clip down one and if wires were hooked up incorrectly it would not run perfect this time and bad that time, I checked the shaft for the distributor for play up/down and side to side as well as rotation there is no noticable play in it, as for the splices yes under the relay box I resoldered all I found cut the wires back and respliced as stated earlier 3 into 1 red/white stripe some purples and some blues.