96 XJ Running irregular

My 200k truck was fine until recently, then my slow leaking radiator took a crap on me. The engine light came on and I tried to make it to the exit but the side of the radiator that had the leak burst.

At first after changing the radiator, I didn't notice any weird engine stuff. Then I dismissed a bunch to the fuel filter I have never replaced.

Things I have recently done (myself or friends) :
Crankshaft positioning timer - 4 months ago
sparks at .035, spark plug wires (all perfect light toasty even with 80k on them) - 3 weeks
New radiator, upper hose, air filter, thermostat - 2 weeks
fuel filter, battery terminals cleaned, wires cut back (but still need hot replaced - couldn't cut far back enough, but better than it was)-days ago

Also had suspension work at Les Schwab:
all shocks, front tie rods and related etc - 1 month

Also just passed emissions and can't remember if it was before or after radiator. But it was after sparks and wires.


Now I am getting some irregular missing with occasional power loss. The other day I backed out fine, then hit the gas and had almost no go. Thought it was tranny since engine didn't draw my attention. Now it seems to be random slight cases of the wimpys but haven't been able to duplicate that extreme.

Conclusion:
1. bad sensor(s) - O2 #1 suspect
2. warped head? causing O2 to crap?
3. O2 has probably never been changed and overheating it finished it's life with very annoying timing?
4. Bad grounds due to rusty radiator goo being sprayed everywhere?

Going to replace dist cap and rotor regardless. But I don't want to shotgun anything else. Ideas?

forgot to mention in previous post that when starting, the battery acts like it is drained - sluggish turnover. Which is why I went after the corroded terminals... I was hoping some extra radiator fluid on my terminals was making for a crappy electrical connection and a computer brain fart was the result. Didn't do anything different.

:scottm:

cut back ground wire... helped some with sluggish starting.

Although this works best if you can run the engine to get it warm, with the '96 you can still pull codes:
Shut the engine off
Turn the key to ON (but not start)
OFF
ON
OFF
ON...and wait

The Check engine light should start blinking after about 5 seconds. The pattern is that it will blink the 'tens' and then the 'ones' followed by a slightly longer pause before continuing. It will always give a "five-five" (55) code that indicates "end of codes"

Got the head-to-firewall ground still in place and in good shape?

Well I lied... just left me stranded about 10 minutes after my ground wire post!

I think there are 2 problems. My starter might be crapping too.

I did the code thing after this time and I believe it flashed 12 and 55. I would check it again but I walked home.

Going to replace the forward Oxygen sensor and the battery wires today. Also cleaning and checking all starter and ground connects. Then if it doesn't run perfect and start like a ner car I am doing the rear Oxygen sensor and the starter.

After that I run it off a cliff.

Ok - new starter (#2 due to Pep Boys). 1 prob seems to be solved. O2 forward sensor replace tomorrow is the plan. Hopefully done after that.

Make sure to buy a distributor cap with brass terminals.

12 - Battery has been disconnected (within the last 50 keystarts, IIRC)
55 - End of codes

Nothing really usable from that, I'd say.

Please 'splain more about the CPS positioning timer??