After driving twenty to thirty minutes the car starts vibrating

Hi,

It can be a few things. When I hear power loss, my first suspect is a partially plugged catalytic converter or low/high fuel pressure.

In this case, what I suggest is to pull diagnostic trouble codes so we know which direction to go.. This vehicle has an OBD 1 system which doesn't require a scanner to get codes. All you need is either a short jumper wire or even a paper clip.

Here is a link that explains how to retrieve the codes. Follow it and let me know what codes are found.

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Let me know what you find or if you have other questions.

Take care,
Joe

Only code that pops up is code 41.

Hi:

The code is related to the camshaft position sensor. The first thing I would suggest is to check the connector at the sensor and make sure it isn't loose, corroded, or damaged. I attached a picture of the sensor to help locate it.

Let me know what you find. Also, let me know if you are comfortable following a flow chart to check voltages, grounds and so on related to the issue.

Take care,
Joe

Well, I took it back off cleaned the connections and took the negative side of the battery off and the code came right back on. so any help from here would be appreciated.

Hi,

At this point it becomes a diagnostic procedure. I have attached three pics below which are the flow chart for diagnosing a code 41. I had to break the flow chart into three pictures so you could actually see them. LOL But I did overlap them so you can follow them.

Try this and let me know the results or if you need help.

Take care and have a good Thanksgiving.

Joe

I got all the way to the second picture assuming I found the BA 12 terminal right. And got to where it says CKT 630 Open or shorted to ground or faulty ignition module. Just really hoping I found the right BA terminal but I’m pretty sure I did so where should I go from this.

Okay, at this point you need to determine if that supply is shorted or open. First, check to see if there is continuity to ground. If there is, it's shorted and you will need to trace the wire to find the short. If it is open, check to make sure that pin isn't damaged or not making a connection. If the connection is good, there is no short to ground, and you still get no signal, replace the ignition module.

Well I was lazy and just replaced the module and I’ve still got the same code so there definitely a short. How do I go about testing everything from here?

Hi,

You have the same kind of luck as I do. If you refer to the post above the one you sent me, it explains what needs done. Basically, you need to check if there is continuity to ground. If there is, then at some point, that wire is damaged and touching something which provides a ground. If that isn't the issue, then you need to if there is a power signal to that wire. If you are not sure on how to perform the tests, let me know.

Joe

So I need to find the power wire and see if there’s power or figure out which wire is the ground and see if it is grounded correct?

I guess I’m not 100% sure on how to test for that is there any diagram for that connector that goes to the ICM that you could send me.

Hi,

Basically, when you check continuity, you are checking Ohms on the multi meter. In essence, you are confirming that power from the MM can flow in one end of the wire and out the other. In addition, checking for power is just that. You need to see if power is available. Here is a link that explains how to use a volt meter/multi meter:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

I attached the wiring schematic I have for the cam sensor. I placed a small red dot at the end of each wire that you are checking. Note that the schematic indicates what each wire is for, ground (low reference), power, and signal.

To check for a signal, you will need a helper to crank the engine.

Have you already replaced the cam sensor?

Let me know if this helps you.

Joe

All right I’ll get back to you on what I come up with and yes I have replace the cam sensor already. So it’s got to be something in the wiring harness or ground or something.

Can I ask where and when you got the cam sensor? Also, have you confirmed fuel pump pressure? And, are you certain there are no issues with the catalytic converter?

I got the cam sensor off Amazon probably a week ago I have not checked the fuel pressure or the catalytic converter could all of that give me a 41 code?

I have to be honest, I wouldn't think so, but they could cause the symptoms you are experiencing. Since the code is the sensor, something seems to be specific to that area. Did the original sensor do the same thing?

Joe

The original sensor did the same thing but the weird part about it is ever since I put this new ICM in it’s only done what it was doing once and it hasn’t done it again yet but I still do have a 41 code.

Have you tried resetting the code to see if it comes back?

Yes I did when I first put it in and it did but I haven’t tried recently.

Just as a test, I would delete it and see if it comes back again. It may have been a fluke that it happened this way.

Also, I really am starting to feel it is simply heat related. Stupid question. You said with the new part it only did the same as the original one time and hasn't done it since. What it the vibration as indicated in the heading or was there something different?

Let me know what happens.

Joe

No it was the same thing loss of power misfiring and vibration.

Was the crank sensor replaced as well?

Yes that has been replaced.

Hi,

The only other thing I can think of for the cam sensor code is a stretched timing chain. Something isn't adding up as far as it misfiring when warm.

At this point, I would run a compression test to see if there is any indication of a timing related issue. Also, and I know it's a year old, I would remove the ignition module and have it tested. That could be the misfire.


Joe