Cam sensor Failure!

[daviss]

My car is throwing a Cam sensor failure code and has been for months. Car has always run albeit rough sometimes. I took it to a local guy who knows Buick turbo motors to swap the cam sensor and fix a few other things. After the cam sensor swap the code didn't go away. He says he's been through the entire wiring harness on the car and everything checks out but can't make the damn check engine light go off.

Any ideas from the Buick techs or electrical wizards out there?

The car still runs but has a really bad stumble down low( beyond normal tip in) and clears up once I get up on RPM. However, performance has declined recently with no modifications being done since the problem started or just before the problem started.

Any help is appreciated. Starting to get cold out, so I probably have all Winter to figure this out.

 

[GNVenom]

You probably have a bad connector, either the one on the engine harness to the cam sensor, or the one on the engine harness to the CCCI module.

I've seen this problem many times.

 

[bison]

Does the problem go away after you unplug the cam sensor with it running?

 

[daviss]

Unplugging the cam sensor with the car running doesn't clear the code. Before he put the new cam sensor in, the car would die when he unplugged it. The new sensor is working fine and seems to be a step in the right direction but the Check engine light still remains.

GNVenom:
When I picked the car up today, the mechanic said he was going to call someone at Casper's, I'm guessing that's you. Hopefully he will follow through. In fact I'll call him and remind him.



Thanks for the input.

 

[ponykiller]

doesn't sound right that the car would die when you unplug the sensor with the car running

 

[onefastcar]

Something wrong car should still run if cam sensor is unplugged and just go into batch mode and fire two injectors simultaneously you will hear the injectors cycling.

 

[daviss]

The car would die before he put the new sensor in. Now the car will still run in batch fire with it unplugged but the Check engine light won't go off.

I'm taking it to another guy that I've known for a long time. I talked to him over the weekend and he says he's seen this kind of problem before, not on a TR, but elsewhere. I told him what you guys thought and what my other mechanic said and I'm pretty sure he has a handle on it.

He also said the new Standard cam sensor(#PC16) was junk. I remember a thread discussing this and the Standard sensor was the same part as the Delco. I bought the Standard sensor about 6 months ago when the parts houses were running out of them. If I have to buy a new sensor, so be it. I just want the car to be right.

Thanks

 

[GNVenom]

The Standard part IS an OEM part.

They only carried the Delco part for this application.

 

[ponykiller]

the cam sensor is only used when starting to let the car know where the no.1 cly is... you can unplug it and it will still run, are you sure your not unplugging the crank sensor, you know the one down by the crank?

 

[GNVenom]

Actually, no. The cam sensor signal is used to initialize no. 1 spark, and is also used to update the sequential timing every two revolutions of the engine...same as camshaft speed. Without the update, the module forces bank fueling which then sets a code. The signal must be present during update request to refresh the sequential injection.

And, for what it's worth, the cam sensor spec for end play is .030" to .090", with 90 thousanths being the maximum "wear" dimension. Any more than that, you run the risk of slicing into the cam sensor cap, damaging the sensor, and also, placing the centerline of the cam driven gear out of alignment with the cam shaft driving gear, causing excessive wear on the gear teeth. Also, another consideration is the fact that too much end play moves the oil pump drive slot away from the oil pump drive shaft, causing potential breakage resulting from less engagement of the tang.

 

[daviss]

We have verified the new cam sensor is good and timed correctly. Everything is working correctly, yet the SES light will not go off and the same code remains. My mechanic is following your advice and is going to check and ohm all the connections and connectors at the module and sensor and everything in between or around.

Is there any chance this is an interference issue with two wires being twisted together or just being too close and mixing signal? The harness in the car was hand built and some of the wires are taped and bundled. Just thinking outloud.

I really appreciate all the time and input you have given me. This thing has got me all wound up.

Steve Davis

 

[GNVenom]

Interference is possible, but not likely since it's a Hall Effect device, and switches low. It's more likely a bad connection, or a bad terminal on the CCCI connector.

If the engine starts, then sets the code, the connection must be good. Bad connection will give you a no-start condition.

Check for voltage at the cam sensor connector; should be exactly the same as at the crank sensor connector. If you have access to an oscilloscope, you can look at the waveform of the cam sensor and possibly see any inconsistencies. That would show you noise, bad connection, etc.

 

[m233roller]

I don't think I'd take to the guy that says the Standard sensors are junk, they are one and the same as a GM unit.

 

[SloGN]

sounds to me like you have a ecm problem. because if it has a cam sensor code present means the cam sensor is not in sync. the engine turns over two rev so sync the cam vs crank before it will fire the inj @ start-up. how is this thing starting up and running without a cam sync @ start-up


i would try a known good ecm.

 

[VadersV6]

Sure its not 180 out? When you're at number one TDC compression stroke, the window should be aimed toward the alternator..not exactly, just in that general area. Also check that the crank sensor is tight and adjusted with equal gap on both sides.

 

[daviss]

He found the problem. The guy who built the car made wired the entire car from scratch. He did a pretty good job, but he incorporated some things that fit his combo at the time. I've been told that this car has been as fast as 11.0 and at that time in the early nineties, that was pretty quick. (He took the girdled motor and PT-70 out when he sold it) He had a toggle switch wired into the cam sensor harness to the ecm i presume to throw the car into batch fire for racing purposes. There was a partial break in the wire @ the toggle switch. We eliminated the toggle switch and the SES light magically disappeared

Between that and a slight adjustment to the TPS, the car is now right and my guy said he had his other mechanic road test it and said it feels stronger than his 12.50 LS1 car. I guess that's not too bad for a TE-60 and 009's not tuned. I've been trying to tune this thing with the cam sensor problem and I guess I've been tuning it in batch fire. That should explain why it's pig rich on the bottom end.

The problem is I still can't run it WOT because during the safety inspection, they noticed the member that the rear upper control arms mount to has seperated (broke in half). I'll start a new thread for this problem maybe with pictures if I can get them.

Thank You again for all your suggestions and time.