Code 18.. crank/cam sensors

pila80

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My '93 PAU decided to just quit running a few times. Starts right up though. It shows code 18, and I had just replaced the the balancer, cam & crank sensors, along with IGN module & a coil Not sure where to go with this. I can check out the connectors for those sensors, but beyond that ...? Any words of wisdom here ??
 

HotZ28

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When you installed the crank sensor, how did you check the clearance between the sensor and balancer reluctor rings? The cam sensor will not cause stalling, however it can cause stumbling and injectors firing out of time. The fact that when it stalls, it starts right up would seem to indicate a momentary loss of ignition signal from either the CKPS, or the ICM. IIRC, the ICM in 1993 did not have a dedicated ground wire and depends on ground from the mount surface. Was that cleaned and properly coated before the ICM install? You may have other problems, but these are the basics.
 

pila80

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Thanks !!
I did make sure of the grounding on that module. but it may be worth a look to be positive about it...
It's been in service for quite a while now since I did that work, so I believe the clearance on the balancer & sensors isn't likely the problem. It does act like the IGN was just turned off, when it quits !!
 

HotZ28

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Some years ago, my PAU MAF failed on the road to nowhere! I disconnected the MAF and drove the car for 2-days and if ran fine, Out of desperation and knowing better, I bought an aftermarket MAF. Once that was installed, about once a week I had engine shutdown while driving at random times. It may have been 2-3 days apart, but when it shut off it was just like I turned the ignition switch off, but would start right back up! I had a warranty on the MAF and got my money back, then installed a Delphi MAF and have never had a problem like that since. Strange things happen with aftermarket parts!
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pila80

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I went through the grounds & checked/cleaned ( again) the grounding of the IGN module. I guess I'll have to pull the right front wheel & get at the pigtails for the cam/crank sensors & do a continuity check to the IGN module connector. Don't think I can do a resistance check on the sensors though....
 

pila80

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Well, my Buick still hates me !
Two days ago, I started it, and began to scrape the frost off of the windows. Then it died. It sat for three days, and a few minutes ago, it started & ran fine. A check of codes show code 18. It didn't let it warm up this time, but maybe I should do that & see if it quits again. I wouldn't know if the engine temp has anything to do with that, or not (???) The other day I checked the conectors on the cam & crank sensors, and the IGN module. Don't have a clue at this point, but it's beginning to really piss me off...
 

g_419369

Thanks for that bit of info. Of course I replaced the cam & crank sensors earlier, along with the IGN module. I suppose I'll have to check spark etc after it quits again...
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pila80

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Well, now I'm wondering about the relation of it quitting, when the engine starts to warm up. Beginning to to wonder if the bracket that holds the coils & IGN module, loses it's ground when the engine warms up. The bracket is bolted to the engine, so.... I'll have to remove all the parts there & see if it's a problem. A dedicated ground on the IGN module mounting plate may be the best idea (?).....
 

pila80

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The Buick is "resting" in the side yard. If it's there long enough, I'll call the scrap yard that hauled my old '85 Caddy away a couple of months ago. Enough is just about enough !
 

pila80

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Thanks for that thread ! When I had replaced both the crank & cam sensors, the engine did miss a bit at high RPM. I replaced the top coil with a used one I had, and that issue went away. I suppose it could still be one of the coils. When cold, the engine starts & runs good, so maybe one of the coils is bad when it heats up. I may change the bottom/foreward two & see what happens ! Or, I could run it until it quits, and replace one coil at a time & see if it helps. I'm not gonna get into this like the guy in that thread did, even though I do have an oscillascope. ( I build tube-type guita amps).. The car has 133,000 mles on it, so it's not a worn out engine etc..,,just OLD like me !!
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pila80

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The Buick is still sitting in the side yard. I'm afraid to take it out on the road ! I'm looking around for a replacement vehicle, and it wont be another GM car at this point. Driving my 507 inch Caddy powered El Camino when I need to go anywhere, or the wife's Jeep !!
 

pila80

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Well, the Buick was running OK, to move it around the yard, but now it wont start....again...
I may spray the connectors with some DeoxIT & see if it helps. The wife & I are looking around for another car....enough already with the Buick...
 

pila80

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The wife and I have found a clean, low mileage Chrysler van, for a family car. The Buick is gonna be history !
 

HotZ28

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I hope you have better luck with that Chrysler van! Sorry you were not able to get the Buick back in service.
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pila80

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Well, we turned down the Chrysler Van.. Just biding our time for a bit. I hate giving up on the Buick, and Maybe I'll tackle it again, if I can get it over to the shop at the airport where most of my tools are.. I'm glad that airplanes aren't this much of a pain in the ass !!....
 

HotZ28

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Go back to post #2 and read the advice/questions asked in the first part, then reply about how you set the CKPS clearance.
 
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