Sorry for the long posting, I.m a mechanic by trade altho not for Chrysler. Recently I was approached by a family member with a 2002 Sebring convertible w the 2.7 v6 that was not running and had milkshake for oil, to do a favor n help him out, after some troubleshooting I determined the water pump was shot. Replaced the wtr pump which in fact had a broken bearing, installed new primary chain, tensioner, guides, crank and cam gears, removed oil pan and cleaned up engine nicely. Assembled all and the problem is I cant get it started, the car didnt start when it came in before the work either, cranks fine, the compression is about 175 psi on every cyl. and the plugs are new. I know it gets fuel because I hear the pump working and because the plugs get drenched w raw fuel, I know the timing is right on the notch, every golden link was in the cntr of the 3 marks. Removed 1 of the coils and inserted a spark plug, grounded it and noticed the spark is extremely weak, small red spark bearely visible. replaced all 6 coils, no help, also replaced the cam sensor twice. Havent tried the crank sensor yet, thats next weekend project, what commands the coils?? has anyone come across this problem or have any thought of what would cause a weak spark and can point me in the right direction I'll forever appreciate it.
Thanks a bunch!

 

OOhh, yeah, sorry. hooked up OBD II there're no codes stored

 

Power to the coils comes pretty much directly from the power distribution center (underhood fusebox). The engine computer controls the firing of the plugs by grounding the coils as needed. (Actually by interrupting the ground which causes the field in the primary side of the coil to collapse, and thereby inducing the spark-producing voltage in the secondary side of the coil.) You'll notice that it operates backward from what you did in that little test. You need to determine if there is a spark (there probably is not one), and then figure out why not. Try unplugging the cam sensor and see if it will start like that.

 

Well...replaced the crank pos sensor no help. when i disconnect the cam sensor it looses the little tiny spark that has when the sensor is plugged in.let it crank for a while but still nothing
Since the computer works just the ground side.....Do the coils are fed 12 v continue when the ignition is on? mine are dead, no voltage at all. The fuse that supplies power to them is dead as well, what feeds that fuse? is there a relay?? wow...Im lost

 

Check the ASD (auto shut down) relay in the fusebox under the hood.

 

Well...replaced the crank pos sensor no help. when i disconnect the cam sensor it looses the little tiny spark that has when the sensor is plugged in.let it crank for a while but still nothing

 

I guess you should start again. Basicly engine needs 3 things to work - fuel, air and spark. Check if the fuel pressure is OK, check if the air is not blocked by something (dirty air filter or some other thing in the tube), and start checking why the spark is tiny. Dcotter0579 and Chrysler tech are most experienced so they migh correct me, but I am quite sure that if any of sensors are damaged (crank/cam position) you should not get any spark. If the spark is weak you should take the schematics and see the current path from battery to spark plug. For example you could could check the wire from battery to hi Voltage coil (might be corroded so it cant supply hi current), then check the ignition coil (this requires a some knowledge, but you should have about 15 kV at hi side), then wire to distributor, then the distributor (contacts inside), then wire to spark plug and spark plug. Check all contacts in that path and the parts and you should find something. There is one tricky thing - electronic commutator (a.k.a. ignition coil driver) that makes impulses for ignition coil on the low side. I don't know how it is made in your car, but it also might be damaged and because of that you could get low output from ignition coil.

 

Hi Dennis...thank you for your input.this is what I gather thus far. 5 out of the 6 cyl are not getting spark. } did some research and found out the following. The way this system works is.....there's no distributor the PCM takes care of distributing the spark at the right time. Each cyl has an individual coil...tthe pcm takes information from the cam n crank sensors and if all is fine activates a relay that supplies steady 12 v to each coil.....the pcm also is encharged of supplying ground to each coil at the exact time it needs the spark....well...that's what's missing....5 out of the 6 coils have no ground sent to them when the engine is cranked.....I did a continuity test and the wiring from the pcm to each coil is good which left me with the conclusion that the PCM is bad...I'm awaiting for a replacement as soon as I install it I will update this posting w the results.....thank you all for your help

 

Please update when you do. I am helping one of my wifes co-workers with her car and it sounds like this my be the issue. Thanks

 

Ok, i was MIA while waited for the new pcm to arrive. The new PCM came today I installed and Im now worse off than when I started. W the new PCM I have no pos, nor neg supplied to the coils. when I turn the ign on The ASD relay is activatd as it should I hear the fuel pump hum for a seond but nothing o the coils......Im about ready to give up.....