crank sensor

b231v6

Senior Member
Joined
May 25, 2001
Can a crank sensor be an intermident problem. Like a miss at 2000 rpm. Does not mater if it is in 1234 or park. Everything else has been changed out. Well almost everything. Sometimes the car goes comepletely dead. Basically is it usually good or usually bad with nothing inbetween. Thanks
 
FWIW & IMHO:
My experience with the only one that I lost was it quit about 2 weeks after a water pump change. It quit, & wouldn't even cough after it quit. Quit mas speed on the freeway at 70, too. I have always heard that they are a good or bad problem, not an intermentent one.
 
I had a brand new Advance Auto unit (Sorrenson maybe - don't recall the type they sell) cause an intermittent miss under throttle. It was like the key was turned off for about 1/2 second every once-in-a-while.

This condition, however, only lasted two days before the sensor totally failed.

I agree that it is usually a go/no go type thing, sounds like a bad ground, but ya never know until it is found - good luck.
 
I've checked and changed so many items from coil packs,modules,t.p.s,maf,plug wires,plugs,starter,positve wire between battery and starter, ground between battery and turbo bracket,changed the three fusible links just to change,Opened up c-100 inspected and cleaned,changed ecm,removed valve covers and checked for busted springs,replaced the waste gate soleniod,delay fan relay,cleaned and checked other relays(fuel pump and fan)removed and cleaned injector harness connection,checked conections for the power brakes checked connections on the ac compressor(there are two on the compressor itself correct?)

I'm going to bring it to a GM mechanic and see if they can narrow it down

Wish a fuse would blow that would make it alot easier or some wires would just melt down near the problem. I can't scratch my hair anymore bacause my scalp is getting raw.

I don't know if the glitch is in the engine bay or passenger conpartment.

Folks who've got a gn to drive, all I can say is congratulations. :(
 
Try this test. Start the car and then unplug the cam sensor. should run in batch fire mode. Check to see if miss is gone, if so replace the crank sensor, making sure that it is installed properly and the balancer is not hitting the sensor that will make for a short life for the new sensor. If you are not comfortable with setting the sensor up find a qualified GM mechanic I have replaced many sensors that were destroyed by improper installation.
 
One of the wires going to my crank sensor was bad and I had the same problem your experiencing, The wire did not appear broke on the outside, but the internal part of it was broke. Hope that helps scott
 
I've tried the cam sensor disconnect with it running to see if it would continue to run-which it does but i'll need to run it up to 2000 rpm and see if it cures the problem.I'll check over the wires closer and see if that's the problem. Thanks for starting points guys. I'll keep you informed on progress.

Car is at a local mechanic now to see if he could find anything.All he says is that the crank sensor seems funny on his scope.He's not a GM mechanic and dose'nt work on these cars. Basically was a shot in the dark to see if it was something simple that I missed.

Will give the two ideas you guys gave me on Monday. Thanks. All help is appreciated. :)
 
badgrandntl said:
One of the wires going to my crank sensor was bad and I had the same problem your experiencing, The wire did not appear broke on the outside, but the internal part of it was broke. Hope that helps scott
That's some scary stuff! It is something I was thinking about in this case too.

These are some old cars and stuff like bad wiring in the harness even when the wire looks good is a possibility and something that could happen to any car over time.
 
O.k.... drove the car with the cam sensor unplugged. Drove fine,maybe were getting somewhere. Shut the car off and plugged the sensor back together. It actually drove fine for about 10-15 minutes. Then it started doing the missing studdering thing again. Drove it another couple of miles,pulled over and dis-connected the sensor again. Drove home with no problems.


Would the first step be for me to pop the cap off and check status of the internals. Then reset the sensor(I've got a Caspers tool).I did loose the tape though. Is it 1.45 inches?

Maybe I'm getting closer to a happy concusion. But I remember from my gamb'lin days Not to start churping until it's over.
 
It is 1-15/32" or 25 degrees after top dead center. The sticker works best. Maybe Casper's could fax or email you a copy of the sticker and you could cut it out or you could wait for them to mail you one.
 
I didn't see how old your timing chain is. My car did this too... My camshaft sprocket was so badly worn I was amazed it even ran at all, let alone not skipping a few of the missing teeth!

When I unplugged the sensor, the car ran way better. Plugged it back in, and not much later, started running poor again... But not all the time bad. I replaced the sensor... Same deal. Always had more of a problem at the higher RPMs. Car had 145K miles at that point.

Your description of the Cam Sensor Unplugged vs. Plugged is similar to what I went through! My problem was the timing chain.
 
23,000 miles. Hopefully not a timing chain or sprocket. I have went thru the oil and cut-open a filter to check for any think metalic and or foreign, found nothing. Also run a magnetic oil drain plug. Have not found or noticed and increase in metal filings. I have no knock or strange noises. This has been going on for over a year. When my tape mark arrives from Caspers, i'll reset my cam sensor and see what happens. Jeez it runs so much better with the sensor dis-connected. Maybe i'll pull a click and clack deal and cover up the ses light with black tape and just drive it. :eek:
 
O.K. figure this. I have'nt recieved my cam sensor marking yet from Caspers,so I was reading on the other site about past experiences with like problems. One discussion talk about before you go about resetting the sensor from scratch just move the cap about an eight inch or so. So I did and its running fine.Well at least for an hour. My question is,can the sensor move just a tad bit over time. The car is normally set to run 25 lbs of boost on the street. So it's had it's share of hard driving. I kinda gun shy now,so I'm going to slowly build back up.This episode has really made me think twice about beating this engine. No more than 19/20 lbs from now on. :(

Will just have to see how long this runs good now. Thanks to all that put their suggestions in.
 
If your problem continues to happen, you should look hard at the CRANK Sensor, not the cam sensor. You can try a new cam sensor cap as the whole cam sensor doesn't need to be replaced unless it is excessivly worn/noisy. 95% of the time when experincing the symptoms that you describe and unplugging the cam sensor seems to cure it, it has turned out to be a faulty or improperly installed CRANK sensor. Just my 2 cents. :rolleyes:
 
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