Mechanics

CAM POSITION SENSOR

1990 Cadillac Deville • V8 2WD Automatic • 173,400 miles

Car is stalling while driving, more often city driving than the highway. Car is running rough.
Error Code E41 "Cam position sensor"
This is all intermittant. While driving the Engine Service Light will come on then go off,
repeatedly.
Can you help with this error code?
Does this car have a cam position sensor?
I have replaced the ignition module which made the error / happen less often, only.
Avatar
Cferry1
April 6, 2011.




(p.S.) I have ohm metered the Pickup Coil per the Chilton Maintenance book and it read 853 ohms - OK

Tiny
Cferry1
Apr 6, 2011.
It has a cam and crank positioning sensors

Tiny
Rasmataz
Apr 6, 2011.
Hello rasmataz -
Where do I find the Cam Position Sensor?
How would I change the Cam Position Sensor?
I looked for the Hall Effect Switch and could find it. Is the Hall
Effect Switch only a after market add on for special cars?
What are your recommendations?
Thank you
cferry1

Tiny
Cferry1
Apr 6, 2011.
As the owner of this vehicle. The following has been done since last post.(1) Repaired cracked Air Cleaner Vent Hose which runs from above throttle body to right side engine side manifold or head.
(2)I have disconnected the wiring for the IAC unit.
(3)Installed a new MAP Sensor temporarily - no change.(4) Backprobed the O2 Sensor read lean mixture at idle - o2 sensor appears OK. (5) Carb Choke Cleaner into Throttle Body.
Presently, (Of course) Idle is High. Largest problem now appears to be when Engine is Cool, then the engine is very Rough Running at any
RPM above Idle. It takes about 10 - 15 minutes before it smooth's out.
Can a 2carpro's mechanic make suggestions here and post?
Thank You

Tiny
Cferry1
Apr 8, 2011.
http://www.2carpros.com/articles/engine-misfires-or-runs-rough

1.Defective spark plugs
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
10.Throttle position sensor.
11.Manifold absolute pressure sensor
12.Mass Airflow Sensor
13.Idle air control valve

Note: If it doesn't apply disregard it-
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Tiny
Rasmataz
Apr 8, 2011.
Thanks rasmataz.
Today I was able to measure Timing and it appears from first check that it's reading 20 deg. BTDC. Should be 10 deg. BTDC. A 15 mm Distributer wrench - hard to find tool.I just purchased a set of Crowsfeet to the adjust Timing and ordered the 15 mm special tool. I'll post back with an update.

Tiny
Cferry1
Apr 8, 2011.
Cam position sensor is hall effect switch inside distributor. It will cause no symptoms aside from check engine light(E41), and perhaps a longer than normal crank to start time, as it determines synchronizes #1 injector for faster start. The typicallly start to fail as the weather starts to warm. The higher idle/stall may be because of the throttle switch that is integral to the isc motor. If it is seeing the throttle at rest when it is not, it will pull the shaft all the way in, as it is trying to control idle based on faulty information, and the result will be a stall. If it is not seeing the throttle at rest when it is, then it will think that a stall is about to occur, and extend the shaft, the result will be high idle. The TPS could be misadjusted, and/or idle relearn procedure may need to be performed. This condition may cause what is known as a sail-on, or the idle takes a bit of time to come down, but it should come down eventually. Often times the symptom for this is when, after acceleration and coasting, the vehicle will almost seem like it is accelerating. The rough run could be result of secondary ignition issues, or being a 1990, you are also in an era that saw alot of problems with shorting injectors, and that may explain the errant O2 readings.

Factoryjack
Apr 12, 2011.
Another note of mention, and it may explain the timing that was 10 degrees advanced, is did you have the diagnostic connector grounded placing it in base timing mode? This would be done by jumping terminals A and B in the diagnostic connector with the engine running. You will notice an RPM change when it reaches base timing mode.

Factoryjack
Apr 13, 2011.
Thanks gstacey. Yes, I had pins A & B tied together, prior to starting the engine, although. I do need to go back and adjust timing again since last adjustment I made
it sitting at around 24 degrees BTDC, as read. Why - because at 24 deg. Was where the Manifold Vaccuum increased to highest obtainable - approx. 17 psi. - At my high idle of 2500 rpm. I still believe that I have a small idle issue... Although it doesn't appear to harm anything. Round Tuit.
IN CONCLUSION : I purchased the Haynes Repair Manual and read more about this mysterious CAM POSITION SENSOR. Yes, I went back into the Distributer Housing and found the Cam Position Sensor (Hall Effect Sensor/Switch) this time ! Replaced it.
ALL Error codes have dis-appeared for three days now ! No more Running Rough neither.

Tiny
Cferry1
Apr 14, 2011.

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