90 olds crank sensor trouble


MikeWolf
07-07-2010, 01:08 AM
hit a massive puddle the other day, missing splash shield has caused nothing but hell. belt slipped, wrapped itself around the crank, bent reluctor and split sensor. bent back old ring, installed new sensor - misfire and stall out in reverse. bought new balancer but used same sensor that i just got, set gap .020 and checked 3 times roughly 120 degrees apart.. ran fine for a few minutes but still ended up misfiring and stalling out. tried setting using thick rubberband all the way around the ring as someone mentioned on this site years back for a nissan but ended up faintly worsening. would the old reluctor hitting that new sensor do enough damage to the point of having to replace it again? gonna set the air gap back again with a feeler gauge tomorrow before making a run to the store for another ckps but welcoming any suggestions/comments/explanations/advice/information that anyone could offer me here in the meantime..

maxwedge
07-07-2010, 07:46 AM
Are you sure it is a cps issue, look at wiring to the icm and consider the icm as bad also, usually if the cps was the issue it would not start.

MikeWolf
07-07-2010, 09:45 AM
took caution to the wind on this before i had even taken a serious look at the ckps in the first place, measured primary and secondary resistance at the coil pack and had dude at autozone test my module. came across my mind though that there still might be a problem there, i'll repost what i discover after a little furthur follow up today.

MikeWolf
07-07-2010, 11:11 AM
new module, new coil pack.. same hesitation, heavy misfire, stall out. is there something im missing here? this has me stumped.

maxwedge
07-07-2010, 11:42 AM
Assuming this all started form the mentioned incident, I guess you need to get it on a scanner and look at whether you are loosing the rpm signal to the pcm, this points toward the cps or wiring or the pcm itself. Of course low fuel ressure could cause this or the more common maf, disconnect it (maf) and see what happens, they were famous for failing also.

MikeWolf
07-07-2010, 12:23 PM
I don't have access to a scan tool (would really help if i did and could get some sensor readings) but used an obd1 code reader on the aldl - it just flashed 12 repeatedly, indicating normal system operation. fuel pressure holds about 40psi and doesn't drop. compression around 150psi on all 6 cylinders. pulled the front cover to check if the chain jumped a tooth - but timing was good. cut exhaust before converter to rule out possible clog that might have explained the increase in back pressure. you think the maf would have that much influence upon initial start up?

MikeWolf
07-07-2010, 06:01 PM
besides turning on the MIL, engine cut off immediately after plugging MAF back in while running. is this a significant indication of possible fault?

maxwedge
07-07-2010, 08:03 PM
So did it run with the maf disconnected? When you plugged it back in it stumbled, if so sounds like it is bad.

MikeWolf
07-07-2010, 08:36 PM
yes it runs momentarily while disconnected but once again, do you think it would have that much influence after 30 seconds run time?

maxwedge
07-08-2010, 05:01 AM
Could.

MikeWolf
07-08-2010, 09:07 AM
strangest thing.. I unplug the IAC and it starts and runs better than ever? still some backfiring where i cut the exhaust but still seems like i might be onto something here. gonna mess around with this route for a little - will get back with any findings (hopefully)

MikeWolf
07-12-2010, 01:18 PM
turned out that it was all because i didn't tighten the icm mounting nuts, causing a loss of ground from engine vibration.

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