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Need Help With Timing

Again, your explanation is water tight.

However.......

When I replaced my IP it did not do its own TDCO learn after x starts. When I initiated the TDCO learn with my scantool the TDCO went out of range with the new IP.

Therefore, if the TDCO had happened on its own, it would have set the out of range code.....but it didn't......

Maybe my 'Canuck' truck doesn't understand what its supposed to do......
 
I think you'll find, reviewing those early almost interminable posts, that the problems were caused by unfamiliarity with a newly acquired scantool, coupled with unfamiliarity with the procedures required to execute the commands - Tech2 will not permit access until certain conditions are met - GMTDScan has no restraints, thus having resulted many errors in the hands of the uninitated - which justifies the exorbitant pricing of the Tech2 and other factory scantools.

Now, having posted the specific procedures many times on many forums, I could say: had people listened, those errors would not have occured - however, in lieu of that, I'll just say (if only to be on the safe side): had people listened, those errors would not have occured

Again:
command TIMESET and PCM locks in a preset timing number of +3.5*BTDC, which we will call BASE timing, so the engine will stabilize and continue running - Desired is +3.5*, Measured is to be determined: PCM then rotates Optic Sensor\Camring to the most negative mechanical position allowed by the IP housing, then to the most positive mechanical position, for a total of 11*\22* crank MEASURED, which determines the range of advance from +3.5*BTDC - now, PCM is expecting range to be +3.5* plus 22*, which will result in a TDCO value of -0.5* - if IP has been moved, PCM will see different numbers at negative end and positive end, such as +5* plus 22* - a new TDCO value will then be calculated because the range has shifted, allowing more positive advance

Here's where the problem occurs when not using a Tech2: if Engine Coolant Temperature and Intake Air Temperature are below normal operating range when TIMESET is commanded, PCM locks in the BASE +3.5* number - however, in the background PCM is still calling for advance as required by the below-normal ECT\IAT - TDCO will be calculated from those advanced positive values, just as if the IP had been rotated in a positive direction - same-same alla-time same ting for more negative numbers, no sweat, GI..............

So: if ECT and IAT are stabilized at normal operating temperatures, PCM will be calling for zero advance, and TDCO will calculate properly from BASE timing - BASE timing is shifted according to IP mechanical position - useable range of ADVANCE is dictated by that mechanical position - TDCO is calculated from that range of numbers, which is why the numbers will shift upward if the engine rpms are increased - go over ~1500rpm, and you will get the TDCO DTC because the increased value is out of range

That is the way it works, irregardless of geographical location - TIMESET and TDCO LEARN were combined for OBD2, but even the OBD2 ko-ko diddy-wah fingersie\footsie thingy won't work if ECT\IAT are not normalized
 
Last edited:
Huh?):h
Just kidding. No I really do understand the principle of it. Actually GMCTD hit the nail right on the head. My confusion was more over procedure than how it works. The how it works thing I get. I had the luck of seeing a vendor at the connex show last year who had a DS4 cut open so i saw all the little thingys. Pictures worth 1000 words. Just get confused with timing procedures but am very close now. Only thing if you can't get the range of TDCO you want then move pump, don't increase rpms right ? Also if my understanding is right when you click TDCO "on" with gmtdscan you are looking at what it's actually doing and if you are pretty close you can "off" and it will lock in value but in my case since mine was fluctuating between -1.94 -> -2.02 I need to move Mr. IP towards El Turbo a c hair and relearn and hopefully see the # I'm looking for . Now here's the 50$ question(JD you take cash or check ?) When I go to readjust by turning at the above mention point do I relearn base and tdco or because I am so close with TDCO(at -1.94 want -1.50) do I just relearn TDCO ?
How my doin ?
BTW Maybe Steph should have a test you must pass before he sells you GMTDScan....:)
 
You will always have best OBD1 results if you do TIMESET any time you move the IP - PCM needs to know the new range - 1mm = 2*
 
Appreciate the explanations as always jd.....that's why we keep you around....
 
OK so I had my intake off and decided to bump the IP a C . D/M is still 9.5 TDCO is 1.24. close enough for winter. well within acceptable spec and truck is happier when cold.
 
This is my latest snapshot. INJ Pulse width looks alot better. Maybe it was the batts.

Snapshot created 11/4/2008 8:50:38 PM
__________________________________________________________________
ENGINE SENSORS
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Engine run time: 00:01:22
Boost pressure (MAP): 14.2 PSI
Desired EGR: 11.68 PSI
Desired idle: 562 RPM
EGR pressure: 11.68 PSI
EGR duty cycle: 44.5 %
Engine coolant temp: 186.4 F°
Engine speed: 562 RPM
Glow plug relay feedback: 0.1 Volts
Glow plug voltage: 0.2 Volts
Ignition voltage: 13.1 Volts
Wastegate duty cycle: 80.1 %

__________________________________________________________________
INFORMATION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
PCM Calibration ID: 4805
Current DTCs: 0
Accel. ped. pos. 1: 0.57 Volts
Accel. ped. pos. 2: 4.53 Volts
Accel. ped. pos. 3: 4.1 Volts
Barometric pressure (BARO): 13.56 PSI
Battery voltage: 13.1 Volts
Fuel temperature: 88.9 F°
Intake air temp: 85 F°
Throttle position: 0 %
Turbo boost (Calculated): 0.64 PSI
Voltage reference sensor: 1.3 Volts

__________________________________________________________________
INJECTION PUMP SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Actual injection pump timing: 31.5 Deg °
Cam reference missed: 0 Counts
Crank reference missed: 0 Counts
Fuel calibration: 150 Counts
Fuel rate: 7.81 mm³
Fuel rate - Cruise: 0 mm³
Fuel rate - Idle: 7.81 mm³
Fuel rate - Maximum transient: 44.69 mm³
Fuel rate - Throttle requested: 0 mm³
Injection pulse width: 1.8 ms
Injection timing - Measured: 9.6 Deg °
Injection timing - Desired: 9.5 Deg °
TDC offset: -1.23 Deg °

__________________________________________________________________
TRANSMISSION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
3-2 PWM solenoid duty cycle: 0 %
Cruise target speed: 0 MPH
Cruise speed error: 0 MPH
Current gear of transmission: 1 Gear
Current torque signal pressure: 25 PSI
Current transmission ratio: 1:4 Ratio
Error between desired and actual shift times for latest 1-2 upshift: 0.12 Sec
Error between desired and actual shift times for latest 2-3 upshift: 0.08 Sec
Force motor (PCS) - Duty cycle: 34.4 %
Force motor (PCS) - Feedback current: 0.62 Amps
Force motor (PCS) - Reference current: 0.62 Amps
Time of latest 1-2 upshift: 0.28 Sec
Time of latest 2-3 upshift: 0.28 Sec
TCC PWM solenoid duty cycle: 0 %
TCC slippage: -28 RPM
Transmission input speed: 595 RPM
Transmission output speed: 0 RPM
Transmission temperature: 143.6 F°
Turbine speed: 595 RPM
Vehicle speed: 0 MPH

__________________________________________________________________
STATUS FLAGS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Shift lever:
Park/Neutral

Cruise control:
 
Since I cut the TDCO back to -1.23 I notice the truck starts better. Shouldn't that be the opposite ? Also when I did timeset I was floating around 3 deg. was that ok to proceed to TDCO Relearn. Above was the snapshot after I did both after moving the pump.
 
The only thing I would watch is the fuel rate at idle. If it drops below 7 you will run into issues....
 
From what I understand, a worn head/rotor will eventually cause a drop in idle fuel output.

When my IP tanked, it was showing less than 4 mm^3 at idle, the rebuilt IP I got from a 'Diesel Pro' is putting out over 9 mm^3 at idle which is exactly where Bill said it should be....
 
TIMESET will always show fluctuation around +3.5*BTDC - that is where GM\Stanadyne needed to set the timing to provide the most power while still qualifying with EPA emissions specs for a passenger vehicle - F**d and Dodge didn't bother with that rating, opting for the medium duty 2500 and 3500 truck ratings - also, the invariable 3.5* reading proved to the adventurous tech that altering IP position did not change timing, just like the FSM states - result was that the extreme difficulty in rotating the IP, and the seemingly negible timing change meant that each 6.5 that rolled outta the shop left with oem timing specs, fully compliant at DOT emissions inspection stations - good thing for Jim Bigley's The Diesel Page, which encouraged experimentation, and brought together in one place people who had done some, incl Matt at Peninsular and Bill at Heath, which resulted in the 6.5TD Project Truck, and other notable examples amongst the lay membership - the Diesel Place and others spun off from there due to differences in opinion and direction and such - and that's the..........rest..........of the story
 
Yeah I'm going the "pro" route probably next spring. Since the weather cooled off and I have not been towing the hot start problem kinda fixed itself for now. I know my pump is weak.
 
My IP timing results

I've read this whole thread... and have been working on two 6.5's as far as IP timing. I can't get my TDCO to be negative, it always sets to about .50 according to the software, but when I take a screen shot it reads .09. The truck seems to run ok but I think the TDCO is supposed to be -1.50 to -1.94.

Both of the engines I'm working on are giving the same readings. Screen shot below. Fuel is hot b/c it's SVO.

I usually use dieselplace.com but Stefan directed me here, looks like a lot of the same great sources of knowledge!

Snapshot created 11/12/2008 12:41:34 PM
__________________________________________________________________
ENGINE SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Engine run time: 00:29:34
Boost pressure (MAP): 12.03 PSI
Desired EGR: 15.23 PSI
Desired idle: 694 RPM
EGR pressure: 12.33 PSI
EGR duty cycle: 0 %
Engine coolant temp: 179.9 F°
Engine speed: 675 RPM
Glow plug relay feedback: 0.1 Volts
Glow plug voltage: 0.1 Volts
Ignition voltage: 12.6 Volts
Wastegate duty cycle: 99.6 %

__________________________________________________________________
INFORMATION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
PCM Calibration ID: 5145
Current DTCs: 0
Accel. ped. pos. 1: 0.67 Volts
Accel. ped. pos. 2: 4.39 Volts
Accel. ped. pos. 3: 4.06 Volts
Barometric pressure (BARO): 11.42 PSI
Battery voltage: 12.9 Volts
Fuel temperature: 162.5 F°
Intake air temp: 124.7 F°
Throttle position: 0 %
Turbo boost (Calculated): 0.62 PSI
Voltage reference sensor: 1.3 Volts

__________________________________________________________________
INJECTION PUMP SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Actual injection pump timing: 31.33 Deg °
Cam reference missed: 0 Counts
Crank reference missed: 0 Counts
Fuel calibration: 135 Counts
Fuel rate: 4.38 mm³
Fuel rate - Cruise: 0 mm³
Fuel rate - Idle: 0 mm³
Fuel rate - Maximum transient: 59.38 mm³
Fuel rate - Throttle requested: 0 mm³
Injection pulse width: 2.16 ms
Injection timing - Measured: 9.8 Deg °
Injection timing - Desired: 9.7 Deg °
TDC offset: 0.09 Deg °

_________________________________________________________________
 
BB please update your signature so we know what flavor/yr of 6.5 we are advising on, what tool are you using to initiate the TDCO learn 12 psi for MAP at idle ????, that is 2500 rpm boost level, do you have any stored codes, TDCO won't happen if you have active codes, with 12 psi at idle I would suspect code P0236 to be active. 31.88 deg actual timing isn't right either for idle 8.5 to 12 should be max depending on your tune and if cold timing advance it still keeping engine revved up for warm up
 
Thanks, I just copied my signature from the other forum. I am using the GMTDScan Tech, and did TDC Time Set On, then Off, then TDC Learn On and let it cycle to finish.
 
Okay those are OBD-Is NVMTNLION is your best bet if he doesn't chime in this thread PM him, he & Stefan Beta tested scantech on his 6.5, NVMTNLION may have some tricks to share with that tool, I'm up to speed with Tech-2 and MT2500 as it allpies to OBD-IIs
 
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