97 CMP Offset PID

[WICruiser-97]

I have read other threads on this subject but newly registered to allow me to actually post here.

I have a '97 C1500 w/ the 5.0 Vortec that I recenlty rebuilt. Installed the distributor with the rotor pointed to the "8" and the enigne runs but thows a code for cam offset.

I have the Torque Pro app and a BAFX wi-fii OBD interface that can see the typicaly information like rpm, ignition advance, etc.

I have tried installing an extra PID: OBD Mode 221301 but that does not appear to work (when I test I get an error). If I leave the OBD Mode blank I get a number for the PID but it appears to be fixed and not related to the distributor position (-16.2 if I recall correctly).

Any thoughts about what I may be doing wrong? I need to get a viable CMP Offset reading to allow me to adjust to the +/- 2 degrees required to eliminate the code.

Thanks

 

[Macs Garage]

I have a 99 k2500 5.7 vortec and didn't need to add any extra PIDs to read the camoffset. Should be 0 plus or minus 2. Are sure the sensor is plugged in?

 

[Spareparts]

You can only register the reading above about 1k rpm. Below that rpm it is fixed

 

[WICruiser-97]

The typical sensor readings like rpm, intake vacuum, ignition advance, etc. all read what appears to be reliable numbers so I believe the sensor is plugged in a functional.

If I have the sensor plugged and connected to the app when I edit the special PID I added and I try to "test" it nothing is returned - reported as no data; if I remove the OBD Mode 221301 and leave that line blank a try to "test" I get a fixed value that never changes regardless of engine rpm, shut off and restart, etc. I have tried two variations of the PID formula ((signed(A)*256+b)80.063) and ((signed(A)*256+b)*0.024) without any affect other than the fixed value returned under test is different.

I read that the '97 models may have a different PID than the "98 and later but do not know if that is fact or speculation.

 

[WICruiser-97]

I just noticed a typo in the first forumla above it should read ((signed(A)*256+b)*0.063).

I should also say that the formula resluts when the test does work shows the interim calculations but I did not pay attention to what it was using as "A" or "b". Without confirming my impression is that whatever "A" and "b" are they are fixed values so the forumla is not working as intended.

 

[Schurkey]

This is one reason I use an actual scan tool instead of a laptop and computer program. I didn't know what a PID was until I started paying attention to GMT400.com.

 

[WICruiser-97]

I understnad there is a floating loaner scan tool circulating among forum members. Does anyone know if that scanner would work for reading and then adjusting the cmp offset?

I also need to bleed the ABS unit on this truck so if this scanner would work for both the cmp offset and the ABS bleeding process that would be great.

I don't want to waste everyones time getting on the ist for the scanner if it will not work for what I need.

 

[Schurkey]

I understnad there is a floating loaner scan tool circulating among forum members. Does anyone know if that scanner would work for reading and then adjusting the cmp offset?

Worked on my '97 K2500 7.4L

I also need to bleed the ABS unit on this truck so if this scanner would work for both the cmp offset and the ABS bleeding process that would be great.

CMP--Yes. ABS--I don't think so. I think the Snap-On software needs to be newer than what that tool is equipped with to chatter the ABS valves. Version 8.2 (Supposedly released in 2008, 2nd Quarter) is not new enough. 14.2 will, and I've heard that 10.x will.

 

[WICruiser-97]

Thanks for the feedback on the scan tool for the CMP and negative on the ABS.

 

[WICruiser-97]

Trying to determine if my stalling problem is related to the CMP offset.

Driving it yesterday it was fine cold but as it got warmed up it started stalling when accellerating from a stop. It would easily restart and I could manipulate the throttle to keep it running and accellerate (seems to run better when pedal is depressed further) but it would repeat at the next stop and seemed to be getting progressively worse.