Crank Sensor on '94 3.4L... 1 or 2?

[94Redbird]

I was under the impression that the knock sensor and crank sensor are the same thing so correct me if I'm wrong first of all. I'm having trouble with my car and I almost sure that's the problem so I went to order up a new sensor and the guy tells me the car has two... one on the side and one on the front. So then I figured well maybe this front sensor is causing my problem but when I got under the hood of my car I couldn't find any other sensor. Could someone tell me if there is in fact 2 or not and if there is where it is located?

[ June 20, 2005, 04:41 PM: Message edited by: 94Redbird ]

[viper98885]

There are 2 sensors. One is on the front of the engine near the front timing cover. It has 2 wires going to it and is a little hard to see. The other is the 3X sensor and is on the right side of the engine block about half of the way back.

[94Redbird]

Thanks... guess I didn't look hard enough.

[montytrmpt]

here's a pic of the front 24x crank sensor.

http://www.geocities.com/v6camaro204...e/engine15.jpg

[94Redbird]

Thanks for the pic. I had seen those wires and figured they were going to the sensor but there was that much gunk around and I could hardly see behind the pulley. Speaking of the pulley I guess it has to be removed to get at the inside bolt on sensor by the looks of it.

[montytrmpt]

yeah, the pulley has to be removed and the sensor isn't cheap either. What is your car doing that makes you think its the Crankshaft sensor?

[94Redbird]

Well a while back I had some similar problems where the car would hardly stay running at one point but at other times would run fine. That turned out to be my crank module. So all of a sudden it just started running off again. There's something going on with the firing it seems. To be honest though I'm starting to wonder now if it's a coil. When the car is idling the tach and oil pressure are bouncing up and down... hard to explain exactly but the pluga are almost brand new and I don't think it's the wires either. Oh and the engine light never comes on so there's no hard code. I tried out the paper clip trick to see if I could pull some codes but it doesn't work on my car for whatever reason.

[Jeanda]

you have any follow-up info on your possible crank-sensor problem? [img]graemlins/popcorn.gif[/img]

[montytrmpt]

94redbird- I might be too late considering a weekend has passed since I last visited this thread, but if not, here's a few thoughts. First, you can't pull codes via the paperclip method. 93 was the last year you could do it on an f-body. for 94 and 95 owners you MUST use a scantool. Second, if the problem is an ignition/engine speed problem the engine rpms would bounce causing the RPMS/tach to bounce with it, and the oil pressure would only naturally bounce with the RPMs. Third, before you buy the crank sensor start with the coils, make sure they are good. A search on this site ought to bring up valuable posts on testing them. (or a good parts store could test them). Take a look at this diagram linked to below, I had a bad connection to a knock sensor that caused a similar problem.

http://www.geocities.com/v6camaro204...ginespeed.html

hope this helps.

[94Redbird]

No progress yet because I haven't had a chance to work on the car since. I was in the process of testing the connection to the front sensor when I brushed my arm up against my oil pressure sensor and it snapped right off so now I got to replace that as well. I am going to test the coils and that wiring diagram will come in handy... Thanks. I'll keep you guys posted as I make progress.

[ June 27, 2005, 11:13 AM: Message edited by: 94Redbird ]

[94Redbird]

OK I did some searching through the forums about the coil testing and I know what I have to do to test them but I can't find the coil specs. Can someone tell me what the primary and secondary values should be?

[94Redbird]

Even though I didn't have the coil specs I went out and put my ohmeter on them and they all gave the same resistance so I'm assuming that's not the problem. I also checked the resistance on my plug wires and they seem ok also... I'm pretty sure the only variance in those was due to the length of the wires. I also checked out most of the connections to the ICM and I put my meter across the 3X sensor and I got a reading so I'm assuming I can rule that one out.

[montytrmpt]

Is this problem only when the car idles? Otherwise when you drive the car is it ok? If that is the case maybe its the Idle air control valve. I'm not sure if it would cause a dramatic bounce in RPMs but if it were sticking it might cause the idle to bounce a little. Try taking it out and cleaning it up. I used a rag to clean mine but mineral spirits/parts cleaner might have been a better choice. If its sticking it won't set a code. It will only set a code if the circuit is broken. Good luck, try the cheap and easy stuff first, when I broke the wire to my knock sensor I spent a ton of money before I realized my dumb mistake.

[94Redbird]

No it's not just at idle. I mentioned how I had problems before and had to replace the module right... well after that it was fine for a month or two and then I took it off the road because I had bought an SUV and I wanted to try and fix the car up a bit. The car was pretty much parked all the time after that except I used to fire it up once a week say and get her up to operating temperature and take it for a run to keep it from seizing up and what not. The second last time I had it out I felt a bit of something happening but only for a few seconds say and then it went away so I said alright I'll have to keep an eye on that... then the last time I took her out it happened again and by the time I got to my driveway it was just running like ****. So that's when I started poking around to try and figure out what was on the go. I haven't had the car on the road since then and I had the battery disconnected as well so once I replace the oil pressure sensor I'm going to hook everything back up and take it for a spin and see what kind of problems exactly I encounter while driving and see if that can't pin point my problem.

[94Redbird]

Well yesterday I finally picked up the oil pressure sensor and installed it after my old one snapped off... I got everything hooked up and battery back in, turns the key to start the car... not a sound. The accessory power works fine and the battery has enough juice but no attempt to start the car at all. All I hear is a relay clicking in the dash as I attempt to start the car and I hear a single click that seems to come from under the hood on the passenger side as I let off on the key. I've checked two and three times to make sure everything is plugged in and I've checked all the fuses. I don't know now if something I did while working on the car since I had it going last is causing the problem or if the starter has coincidently kicked the bucket. Any ideas?