PO 0341

Eldo wrote:

I, too, am glad for Albert's validation.  That last symptom, though, "a slightly rough idle in drive when it gets warm" is way too general for the ICM I think.  When the engine is cold it has a richer mixture & a higher idle-speed, which generally translates to a smooth idle in gear.  At operating temp it is trying to be smog-compliant and little things like dirty injectors or valves, even slightly low fuel pressure can cause that.  That is why I just tried Gumout Regane in the tank - if I could just fix the damned steering & drive that fuel mix through...

I had a slight lope at idle for a long time because I did not know it was important for the three coils to impedance-match. One had been replaced while I was traveling, with a NA type coil, and I drove the car with a slight lope for years. We had been talking on this site about that and I decided to check my coils, just for grins. The new one did not match. I got a junkyard coil, swapped it on - idle smoothed out. I can still balance a nickel on the sight shield, at idle.

Albertj

Wow, should I replace the ICM first or include 3 new matching coils?

carguy8888 wrote:

Wow, should  I replace the ICM first or include 3 new matching coils?

didn't you already check the coils to see that the primaries and secondaries matched? thought you did already...

Me no, but my mechanic did and he said they're fine. Do coils either work or not work?

With the different versions of this engine, the coils also have different values.
The primary-to-secondary test (from the plug-wire output to one of the small 12-volt inputs on the bottom) is one for HIGH impedance/resistance, to ensure there is no short inside - that would be the "work or not" test.

The 'fussier' secondary test & match is to measure between the two primary/12-volt terminals. I can't find any specs in the manual, but as in the aforementioned supercharged vs normally-aspirated scenario (S/C vs N/A) the main thing is to treat them like a compression test: they should all be within something like (Jack, Albert??) 10% of each other. Thus, If the 'perfect' value was 2 ohms, they should all be between 1.8 & 2.2 ohms.

Perhaps one of the others can chime in with closer figures, but that is the general gist of it...
Mark

I personally think my guy tested them when he installed he installed the coil that went bad. If there was a problem I can't imagine he would not let me know.

carguy8888 wrote:

I personally think my guy tested them when he installed he installed the coil that went bad. If there was a problem I can't imagine he would not let me know.

Ha ha I can, but not because he is bad or anything like that.  Many mechanics, good mechanics, deeply dislike electrical aspects of cars.  I think part of the problem is the degree of professionalization and the training many of them get.  

By degree of professionalization, I mean that you have 'fitters,' 'mechanics,' and 'technicians.'  Call those first, second and third degrees.  

Fitters are people who change automotive components as indicated by a mechanic, a technician or a computer.

Mechanics are supposed to be further trained vs. fitters, are supposed to have a greater understanding of how autos work.

Technicians are supposed to be even further trained and experienced in order to deal with electrical and mechanical (specifically, identifying drivability complaints) diagnosis and evaluation.

In the UK, where this distinction is reflected in certification and licensing, a mechanic may keep several fitters busy in a working auto repair shop.  The mechanic will do the technician's part - the diagnosis and verification - and the fitter then is told what to do. Not that many shops in the USA work like that.

A number of people we generally call mechanics in the US are actually fitters. One might presume that fitters typically find auto electronics to be vexing. But I've seen electrical issues thoroughly frustrate good technicians.

Albertj

PS

See https://www.uti.edu/blog/automotive/the-difference-between-a-mechanic-and-an-automotive-technician, http://thebestcarfinanceblog.co.uk/the-difference-between-a-car-mechanic-fitter-explained/

In this instance I can think of an example of those different degrees:
Did he actually compare the primary resistances, or just do the pass/fail test for a short from primary to secondary?

After all, if we didn't have a concentration on this forum of both N/A & S/C owners, most of us wouldn't know about
the difference between seemingly identical coils either...

Eldo wrote:

In this instance I can think of an example of those different degrees:
Did he actually compare the primary resistances, or just do the pass/fail test for a short from primary to secondary?

After all, if we didn't have a concentration on this forum of both N/A & S/C owners, most of us wouldn't know about
the difference between seemingly identical coils either...  

Yep. Remember, I drove with mismatched coils for *years* before I figured that out.

carguy8888 wrote:

In the last 3 weeks I have replaced an internally defective AC Delco wire and a coil.  As soon as I stepped on the gas the car had a dead miss. 2 days later the SES light was going on and off randomly PO 0341 (cam position sensor circuit out of range).  I had it replaced with the AC Delco unit. One day later the P0341 is back steady.
The car is not stalling now thankfully.  Randomly it will feel like it wants to cut out for A second, especially after I put the car in reverse. I really enjoy driving this car but I'm ready to set it on fire and buy a Honda. I read that a magnet can fall off a sprocket and which is a major job,  I really hope it's not that. After doing some reading on here I'm going to have my guy shake the ignition switch.
The car has more power and runs strong,  but I would like to get the light off And I feel a rough idle. Any other help would be appreciated.
1999 s/c 85k.

We have an entire thread dedicated to this code.  The most common cause, a broken wire right at the firewall engine harness connector.

https://rivperformance.editboard.com/t4703-faq-p0341-camshaft-position-sensor-cam-sensor-timing-chain?highlight=P+341+cam+sensor

Skip to my post on this page,

https://rivperformance.editboard.com/t4703p175-faq-p0341-camshaft-position-sensor-cam-sensor-timing-chain?highlight=P+341+cam+sensor

Thanks Larry, I will have them recheck it when I bring the car back for my rough idle, uneven acceleration after downshifting and almost stalling in reverse.

He did not get detailed but he told me he tested them.

Eldo wrote:

In this instance I can think of an example of those different degrees:
Did he actually compare the primary resistances, or just do the pass/fail test for a short from primary to secondary?

After all, if we didn't have a concentration on this forum of both N/A & S/C owners, most of us wouldn't know about
the difference between seemingly identical coils either...  

Have them monitor the cam sensor signal with a scan tool while moving that wire around.  Should take all of 5 minutes.

I will.