cam sensor magnet questions

[Guest xerxes66]

I have a 1990 Reatta convertible.

 

I've tried Padgett's excellent method of replacing the cam sensor magnet through the sensor hole. My magnet was gone with only the shell left. I shaved off the "hat brim" and  JBWelded it in place but I still have the same missing and surging problem. Here are my questions:
How can I test the cam sensor itself on or off the car?

Is there a way to test the cam sensor female connector?

 

I love this car but it's making me crazy!

 

Thanks in advance.

 

[DAVES89]

If the cam sensor code is gone or "history" then you might have to look elsewhere. My guess is the Mass Air Flow sensor.

[bikemikey]

If you have not done so, I would clean the Throttle Body and the IAC. You might consider cleaning the MAF but be careful. A bad TPS, I think , can cause surging. I had to replace the cam magnet and sensor on my 89. It ran fine for a while with a not so good idle, then it started to throw codes here and there, but it would heal itself. I ended up changing out the ECM and now it runs fine, no codes, improved idle. You also might have a vacuum leak around the TB. Hope that helps.

[Ronnie]

I have a 1990 Reatta convertible.

 

I've tried Padgett's excellent method of replacing the cam sensor magnet through the sensor hole. My magnet was gone with only the shell left. I shaved off the "hat brim" and  JBWelded it in place but I still have the same missing and surging problem. Here are my questions:

How can I test the cam sensor itself on or off the car?

Is there a way to test the cam sensor female connector?

 

I love this car but it's making me crazy!

 

Thanks in advance.

 

The cam sensor being bad, or the magnet being bad, will set a code 041. However, I have never known it to cause the symptoms you describe.

 

Just to satisfy your mind that the cam sensor isn't keeping the engine from running correctly you can unplug the cam sensor and start the car and drive it. The gas mileage will suffer a little and the power will be down slightly but you probably won't notice it. I have known people to drive their car for months with a code 041.

The crankshaft sensor is a different story. Saturday, a friend called me up and described an almost identical problem with his '90 Oldsmobile that has a 3800 engine. He knows I don't work on cars for other people any more but he asked me if I would give him my opinion about what the problem might be. I went over and put my fuel pressure gauge on it and it to see if fuel supply was the problem. It held steady at about 40 psi so That ruled out the fuel pump.

 

Then I had him start the engine. The engine jumped and jerked so bad that it would barely keep running. He said it had just started doing it suddenly and he barely made it home before it completely quit. I told him three things came to mind that I thought might be causing it. Timing chain had jumped, the ICM or the crankshaft sensor were bad. He said the timing chain had been replaced about 20,000 miles ago so we ruled that out. That left the ICM or the crankshaft sensor. Monday I saw the car go down the road on the back of a wrecker. He called me later and said a $90 Crankshaft sensor and a $50 wrecker charge fixed it. I have known the ICM to cause exactly the same symptoms. As info: The crankshaft sensor will not set a code. Nor will the Ignition module.

 

If your car only misses under load don't rule out a bad plug wire or spark plug.

[Tom_]

On 3/17/2016 at 6:08 AM, Ronnie said:

I have known people to drive their car for months with a code 041.

Over a year for me.  My problem was when I did Padgett's repair I pushed the magnet in too far and it couldn't interrupt the sensor enough for it to actually register as a signal.  I ended up working over one weekend and redoing the repair without jamming it in there so far and it works flawlessly now.

 

On 3/16/2016 at 4:46 PM, xerxes66 said:

I love this car but it's making me crazy!

I'm pretty sure everyone here has felt that way at some point with these things

[padgett]

But it is all logical unlike this GP I just bought, if it wasn't so rare, I'd have shelved it by now.

 

[harry yarnell]

It's called 'aftermarket radio syndrome'. Hopefully enough of the original harness is available to restore OEM.

[padgett]

What I needed was a Metra Reverse Wiring Harness 71-1858-1 and then spent a full day rewiring things, removing butt splices, and soldering/shrink wrap. Still do not have the separate amp behind the radio working but have not yet figured out where the sub harness terminates.

 

So far removed:

Kenwood radio

JWC changer and remote

Pioneer dual subwoofer with amp and remote

PAC steering wheel control adapter

Some sort of disabled anti-theft device (6 black wires all going to ground and interrupting the starter circuit.)

 

And replaced with a rebuilt OEM radio that works and Besdata cassette adapter with microphone for HFP (same as in my 88. Great sound, much better than satellite)