: crankshaft postion sensor



mikeylok13
09-28-07, 06:30 PM
Hello i own 1997 deville
i have a p0300 code i put on scanner 1.3.5.7 cylinders misfiring put spark tester in between coil and wires very erratic spark 1,3,5,7 can crankshaft postion sensor be the cause of misfire?

Submariner409
09-28-07, 09:45 PM
I believe your vehicle has the earlier 4-coil waste spark ignition system. Basically, the system fires TWO spark plugs at the same time: the "Power" spark, at near TDC of the compression cylinder, and, simultaneously, the "Waste" cylinder which is at (near) the top of the exhaust stroke. If you have weak spark on 1,3,5,7, then something is wrong with the 4 cylinder(s) spark on the ("front??") of the engine, but it isn't related to ignition timing, because those cylinders don't fire in that order. You need a pre-'98 technician. Someone versed in waste spark systems should be able to diagnose your problem quickly. It's probably a simple repair. Good luck! You may need something as simple as new spark plug wires........or, if the coils prove weak, a new coil pack.

Ranger
09-28-07, 10:01 PM
I would venture a guess that the common denominator is the ICM. Make sure all 4 connectors are clean & tight.

mikeylok13
09-28-07, 10:52 PM
thank you for your info icm is what the service manual says i got a icm coil pack from junk yard didnt help ran the same i will look into waste spark system

Ranger
09-28-07, 11:08 PM
Waste spark is not a system. It is just the way the ignition system operates.

mikeylok13
09-29-07, 07:49 PM
changed the icm runs better but still has a miss i noticed if i turn on a/c the car idles fine but in park has misfire

Ranger
09-29-07, 09:15 PM
Sounds a lot like my '97 Deville right after the fuel rail recall. Ended up being the wires. Do a search for "Stutter, Engine or Trans?"

mikeylok13
10-04-07, 06:57 PM
well today i got my wires from rockauto but it did not help the miss

cadillac8686
10-10-07, 02:10 PM
What can a bad crank sensor do? Does it rob from performance, drivability? I know mine is bad because I had my brother put the car on the computer and I have some codes which one of them he said was the crank sensor! how much is a thing like this and what does it take to get it fixed? Any help would be great I just want no problems with my 02 STS

Ranger
10-10-07, 04:21 PM
It will cause intermittent stalls. I think they are about $50 each or so from http://www.rockauto.com. They are above the oil filter adapter, which must be removed to access them (it's still a tight fit). Dealer will charge $400 - $500 for the job.

No need to put the car on a computer to retrieve the DTC's. Your car is self diagnostic. See the as "sticky" in the Tech Tips section.

cadillac8686
10-10-07, 04:35 PM
I know, my car stalls a bit all the time. Now I know why........ I know how to get to the codes. I clear them alot.

Submariner409
10-11-07, 10:20 AM
If you live in an emissions testing state or county, don't clear codes for a couple of weeks before you go for the OBD II plug-in test. An inadequate number of completed driving cycles will show up as a "System not ready" test code and the car will fail.

cadillac8686
10-11-07, 10:37 AM
Thanks.