Hey Guys.
I just joined the forum. Hope you can help me out.

I just picked up a 1988 Olds Delta88 Royale (3800 V6) w/64000 miles from my Mom.

Last Friday, I drove it from Chicago to Minneapolis,
439 miles door to door. The engine sounds great, but
I was getting an occasional "SES" light during the trip.
Also, I felt a thump a couple times when the light came on.

I pulled the codes this using the paper clip method.

13 Oxygen sensor Circuit

Check for a sticking or misadjusted throttle position sensor. Check the wiring and connectors from the oxygen sensor. Replace the oxygen sensor.

41 EST circuit

No distributor reference pulses to the ECM at specified engine vacuum

So, I replaced the O2 sensor, and the code 13 went away, Yeh!
But I still have the code 41.
I've been searching the internet for answers and it seems the cam magnet is the likely suspect. Also, I read the PCM could be the problem as well (even though the error indicates the ECM).

You think its worth replacing the PCM or ECM before diving into replacing the cam magnet? Just looking for some more advice. Appreciate any help.

thanks much.

jasper

You need to pull the cam sensor out and with a mirror and light you can see in the hole. Slowly turn the motor (by hand) and visually check to see if the magnet is there. Then I would look at replacing the sensor since it is a lot cheaper than the ecm.

No PCM in this car, just the ECM (engine control module).

Odds are, you lost the magnet. You'll need to pull the sensor, spin the ballancer, and try to find the hole to be sure though.

Here are instructions: http://www.lesabret.com/phpBB/viewtopic.php?t=5896

Oh, and you didn't replace that O2 with a bosch, did you? 'Cause bosch and GM 3800'* don't get along....

The link provides very good info. Even a novice like me can understand.

I will dive into checking for the interrupter magnet this weekend.

I do have a few questions though...

1) As far as turning the engine. This is done via turning the balancer clockwise, correct? Also, do you think a regular socket wrench should do the trick, or should I use something else?

2) Do I need to remove the water pump?

3) Will I get a good view of the magnet through senser hole or is using a mirror necessary?

thanks,

jasper

A simple no cost way to proceed would be to check all connectors, clean and tighten the sockets. then re-set the ECU and see what you have.

A simple no cost way to proceed would be to check all connectors, clean and tighten the sockets. then re-set the ECU and see what you have.

yea, I agree. I went out to the garage in my PJ'* tonight and rechecked everything in easy reach. I really want to solve this problem myself. Tired of handing my mechanic a wad of cash for every little thing.

Hopefully, I can check the cam sensor connector tomorrow night.

thanks,

jasper

1. Yes, spin the balancer clockwise. It will be easier to turn if you pull the spark plugs but if you've got a cheater bar it'll still go fine with some muscle.

2. No, the water pump doesn't have to come off but the pulley does. Otherwise its hard to be able to see the magnet.

3. You will need a small mirror to watch for the magnet as you spin the balancer. Its just at too funny of an agle to be able to see it right without one.

You can try to reset the ECM after checking the sensors, but the code will probably just come back. However, if you've checked for the magnet and its still there, then consider changing the sensor and that should fix it... but it seems that 90% of the time its the magnet that has failed before anything else.

Alibi,
yea your right, the cam sensor is in a bad spot.
I finally was able to check the connector by removing
the washer fluid jug.
I reseated the connector and reset the ECM code.
I let her run for about half hour last night and no SES light appeared.
But the SES light came on again this morning
when I arrived at work.
Whats strange to me is you would think it would
set a code right away if the cam magnet was missing
or not working properly. I drive 22 hwy miles
to work, then the SES light came on.

I plan to take a look at the cam magnet this weekend.
I'm glad I don't have to remove the water pump.
When putting the belt back on, is there a trick to get
the tension set correctly?

thanks,
jasper

Well, I finally was able to check for the cam interrupter magnet, and she'* still there.
I used a mirror and peeked thru the camshaft position sensor hole.
I had to give the balancer a few turns with a rachet, and the magnet came into view.
Btw, turning the balancer wasn't as hard
as I thought it would be. I didn't pull the spark plugs either.

Anyway, I went ahead and replaced the camshaft position sensor and
took the car for a nice long test drive.
So far, no SES light !! I hope this the end of this nagging problem.

Alibi, SSEBONNE4EVA and myfirstbonnie:
thanks for all your help. I'm sure I'll be back asking for help with other repairs.
Thanks again.

jasper

Belt tension is controlled automatically by a tensioner pulley

Glad you lucked out and its just the sensor! Someone is always around if you have problems with anything so just ask