camshaft retard offset

[ryank99]

ok, i dont want to but i'm taking my truck to have the camshaft retard offset done. i ran a p1345 code and it turned out that the distributor gears were worn so i replaced the distributor with a new billet one. both sensors are good btw. (thanks for the info on diagnosing that code sunlitcomet) anyway, the dealer over here said it will be $100 bucks to perform the procedure but wont gaurentee that the check engine light will go off. my concern is, how do i know they did the procedure and did it correctly?? i talked to 4 differrent service guys before i found one that actually seemed like he knew whet i was talking about :shocked:

[99Yuk]

You can do it yourself if you have access to a scanner. Also the scanner will tell you if the shop has done it correctly as well.

The instructions are as follows:
Setting Timing
Camshaft Retard Offset Test
The ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:

With the ignition OFF, install a scan tool to the DLC.
Start the engine and bring to normal operating temperature.

Important
Cam Retard Offset reading will not be accurate below 1000 RPM


Increase engine speed to 1000 RPM.
Monitor the Cam Retard Offset.
If the Cam Retard indicates a value of 0° ± 2°, the distributor is properly adjusted.
If the Cam Retard does not indicate 0° ± 2°, the distributor must be adjusted.
Adjusting Camshaft Retard Offset

With the engine OFF, slightly loosen the distributor hold down bolt.
Important: Cam Retard Offset reading will not be accurate below 1000 RPM

Start the engine and raise engine speed to 1000 RPM.
Using a scan tool monitor Cam Retard Offset.
Rotate the distributor as follows:
To compensate for a negative reading, rotate the distributor in the counterclockwise direction.
To compensate for a positive reading, rotate the distributor in the clockwise direction.
Repeat step 4 until 0° ±2° is obtained.
Turn the ignition OFF.
Tighten the distributor hold-down bolt to 3N·m(25 lb. ft.).
Start the engine, raise engine speed to 1000 RPM and recheck Camshaft Retard Offset.

EDIT: Acording to this, you can't trust any timing readings under 1000rpm though.

[ryank99]

that was my original plan, to do it myself. i ordered a scanner but come to find out it doesnt read 'cam retard'. the scanners that do are pretty pricy.
($400+ from what i saw). the best i can come up with is just to go by how it starts and runs and of course, hope they dont screw me over

[SunlitComet]

Correction needed for info above. On the 1999 models rpm's must be raised to 2000 not 1000. Any scanner with enhanced GM perimiiters should be able to read cam retard and you don't need to spend $400. If you have the dealer do it you can use a sharpie or colored nail polish as a torque strip(aviation term). When i'm working on aircraft we use it to determine if hardware has been rotating loose warning us something is wrong. Thay should also wipe the code afterwards so if it comes back they missed something.

[ryank99]

i've used some orange stuff called torque seal when i installed gps tracking in vehicles, is was more for tamper evident. anyway, i called a buddy that owns a performance/custom chassis shop and he said he'll do it for me...freebie!
i

[JKmotorsports]

i've used some orange stuff called torque seal when i installed gps tracking in vehicles, is was more for tamper evident. anyway, i called a buddy that owns a performance/custom chassis shop and he said he'll do it for me...freebie!
i

Did you talk to Manny?

[SunlitComet]

i've used some orange stuff called torque seal


Same thing. I am forgetting the names now. I really have to get back to work. I have been away to long.

[ryank99]

its been years since i've used that torque seal, but for some reason its one of things that got stuck in my head, maybe cuz i used it so much

jeff, yep i took it over to mannies shop, he had pacman take a look at it.
no bueno, still throwing a p1345 code:emotions122: i dropped it off to a master mechanic that i hooked with. he knew exactly what the code was and the procedures off the top off his head. so thats a good sign, i'm hoping he can clear it all up for me cuase i'm all out of ideas. its has new distributor,crankshaft sensor,camshaft sensor and i'm sure i stabbed the distributor right cuase it starts right up. im hoping that pacman might have over looked something when tring to zero out the cam retard

[99Yukon_Z71]

If you are close to Houston, I will take a look at it for you!

---------- Post added at 03:08 PM ---------- Previous post was at 03:07 PM ----------

BTW, I advanced my timing 5 degrees to get a bit more power and throttle response. Truck runs awesome now!!! The light wont come on unless there is more than 10-12 degrees retarded or advanced IIRC.

[99Yuk]

...BTW, I advanced my timing 5 degrees to get a bit more power and throttle response. Truck runs awesome now!!! ...

Wait! Going to +5 gives you more power? Really? Please explain?

[SunlitComet]

If you are close to Houston, I will take a look at it for you!

---------- Post added at 03:08 PM ---------- Previous post was at 03:07 PM ----------

BTW, I advanced my timing 5 degrees to get a bit more power and throttle response. Truck runs awesome now!!! The light wont come on unless there is more than 10-12 degrees retarded or advanced IIRC.

Wait! Going to +5 gives you more power? Really? Please explain?

I would like to know this too. This doesn't seem right.

[ryank99]

are you reffering to setting the offset +5* ?? from what i understand it throws the SES code if off more that + - 4*.
but i do see how it could run better just becuase when i had trouble getting my offset adjusted the first time, it was set at 12* retard and it felt like i was pulling a semi, so like the older non computerized ignitions, slightly advanced timing equalled more power.
:hmm:i guess im comfused with the advanced timing aspect just becuase its the crankshaft/camshaft offset that is being changed and not necessarily the timing.

[99Yuk]

I think he is referring to the retard offset that's adjusted by turning your distributor.

So who wants to volunteer to try this?
When it warms up, I will. Just to see if it works and gives me more kick in the butt-o-meter results. It'll be a few weeks yet though...

[SunlitComet]

Setting is 0 degrees + or - 2 degrees anything more and the monkey flips the light switch.

[ryank99]

i wouldnt mind being the test subject, but i dont have easy access to do the offset adjustment. let us know if it works out, cause if its a noticable improvement, im all for it

[amack23]

I have a 96 Tahoe 5.7 V8 with 202,000 miles. I was getting the dreaded P0300 (Random multiple misfire) code so I decided to do a minor tune-up before taking it to get emissions tested. I changed the plugs, cap, rotor, pcv valve and dielectric grease on the usual parts. The wires are not that old and they still looked pretty good so I decided to leave them in. Also, before changing the plugs, I decided to Seafoam her. After this minor tune-up, the P0300 code went away (yes!) and a new one appeared. Now, I have the dreaded p1345 (cam timing issue). I’ve had this Tahoe for 12 years and I never seen a p1345 code before. Is it possible to install the rotor incorrectly? Could I have thrown the retard off? The distributor does not move at all when I tried turning it to see if it’s loose and I even put the old rotor back in to see if the new one was bad. I’m not sure if that was a good test but I did it anyway. Does the rotor button prong have to point in a certain direction or does it matter? It just seems odd to me that changing out these parts can throw this particular code. Any help you guys render is MUCH appreciated!

[SunlitComet]

:welcome:


The cam sensor reads a trigger from the distributor shaft so a rotor change would not do it. If your scanner reads the same rpms as your tach on the dash then assume you setting get disturbed some how and re-zero your cam retard you should be fine. If the scanner sees a much different reading then the dash then you cranks sensor circuit is screwed up.

[ryank99]

i would suggest removing the distributor and looking at the distributor gear to see if its worn. if it is, it will cause excessi e play and throw that code so you will need to replace the distri itor

[SunlitComet]

At which point you would have to definitely re-zero the adjustment with a scanner.