96Cherokee113

I have a 96 5 speed 4.0 and I was driving casually when it backfired real bad and came to a grumbling stall. Now it doesn't get spark. Any ideas on which would be the most likely between coil, timing chain, or CPS? Thanks.

zedpapa

i would start with pulling the distributor cap and crank the engine to see if it is still turning. if its not turning, pull the distributor and check the gear. if the gear is ok, look down the hole and crank the engine and see if the cam is turning. you may need some help.

zedpapa

96Cherokee113

Yea, I was gonna check to see if the rotor was spinning because that would eliminate timing, but we're in the middle of a snowstorm right now. And was still running after the backfire, just very shakily, so I don't think it's the timing.

96Cherokee113

Anybody? Any new ideas? Also, I read somewhere that if I just unplug the CPS and clean it with some electrical connector cleaner or di-electric grease, it may solve the problem? Can anyone confirm that the CPS crapping out would cause the backfire/stall that happened? I'm gonna do it tomorrow, but if I can confirm it now, I'll go outside in the foot of snow and fix it.

Abovetimberline

cps can cause this for sure,it is there for timing,it controls spark and injectors,if it is going bad then check it by checking resistance across terminals b and c,should be a 3 wire terminal,. and see if it is high,should read open or close to open.

96Cherokee113

Open would be 0 ohms? Would you consider close with like the less than 1 range? And terminals B and C would be the furthest right terminals correct? Assuming its a three pin like [---] then it would be A B C ? Thanks for the help, I'll go jiggle it around and see what happens.

96Cherokee113

Alright, it'll have to wait till the morning, the plow truck has pushed all the snow on top of my XJ practically. It'll have to wait till the morning.

Abovetimberline

That is correct,abc. yes open is o or close to it,depending on what scale you select.

96Cherokee113

Alright, thanks for all the great info. I'll be sure to post how it goes tomorrow after I clean the terminal. I've got my fingers crossed.

zedpapa

Open is actually high resistance. 0 is no resistance.

zedpapa

captainwoot

Best guess... your cps just said goodnight, throw ina new one and you shouls be good to go.

96Cherokee113

Yea everybody seems to have a problem with these stupid CPSs. I'll keep everyone informed as soon as I can clear a path through the 16 inches of snow and clear off my Jeep. I'm gonna try the good old unplug, clean, and replug trick to see if it can get me through the day. And if that doesn't work, I'll make sure the timing chain didn't blow before I go buy a new CPS.

96Cherokee113

Alright, well I tried unplugging, cleaning, and replugging the CPS, but it still won't start. I went to pop off the distributor cap to see if the rotor was spinning to see if it was the timing, but I broke both the bolts! Anybody got any good ideas on how to remove these broken bolts. One of them the head snapped off and the other broke in the bottom of the bolt before it reaches the threads. E-Z Outs are gonna be hard to drill the pilot hole for, but I think it might be the only way.

96Cherokee113

Oh, I forgot to ask what I should check next if it's not the timing Check/change the coil maybe?

Abovetimberline

It could still be the cps,cleaning works sometimes,chck resistance on it. As far as the cap goes.pull the dist out and make sure you put it back the sameway,just use a sharpie and make a mark on the housing where the rotor is pointing at right now,that way you can put it back exactly.
I have never seen the screws get broke off,stripp the head but that is it,it will be interesting to see what the inside looks like.