TDCO -1.8 / Carcode Scan Program

[rjwest]

I think I have figured out the TDCO and Timing Learn stuff and how to use the CarCode Program.

Most of the problems I had ( Actually all the problems ) where due to my lack of Knowledge
of the 6.5 Injection Pump, Also doing the first TDCO cmd with the Carcode changed the TDCO from -1.1 to -2.5 and resulted in codes being set.
This really confused me...

Finially got brave enough , and collected enough tools and figured out it was easier to take things off to get at the nuts and made a spanner wrench...

Anyway, adjusted pump, YES, -1.9

So,I got brave today and started messing with the Carcode program..

TDCO: Works, did it several times, got TDCO down to -1.8 ( 1300 rpm ), also, the cmd works when coolant is below 170Deg,

Timing Learn, Enabled Cmd, IPT-(Inj Pump Timing)
was bouncing around 3.5 to 3.8 with occasional
3.1 and 4.0 ( This is Good ,Thanks John Kennedy )

Normal operation- IPT ( Inj Pump Timing )
follows IPTD ( Inj Pump Timing Desired )

Tried the cylinder balance test, It works,

Gives a Result of NORMAL, and can read RPM
digitaly on the data screen, about 15 RPM drop on
each cylinder...

There are some other cmds, , Service eng lite,
AC cmd TCC cmd, and others, WAS NOT BRAVE ENOUGH TO DO THESE

I have the carcode for about a 1 1/2 years,
UPDATES keep being released ( Download from site )
no charge )
I would like to compare it to the Autequity and others if any members in NE florida
or on the way to Maine are interested....

[joed]

rj,

Thanks for your willingness and braveness to test! I too have the latest CarCode version, but have been too scared to try the timing functions. (Especially now that I had the dealer set the TDC offset to -1.94).

Not to confuse things again, but, if I understand correctly, CarCode can set the timing independently of the TDC offset? Reason I ask is that I have never seem timing values as low as 3.5, mine are always at least in the 13 to 17 range (this is in the enhanced data window). I've always wondered if it's set too advanced?

Any insight?

Thanks. Joe.

[rjschoolcraft]

The large numbers you mention should be while driving.

At idle with TDCO at about -1.94, the desired timeing should be about 8.5 deg. Stock timing with TDCO between 0 and -.5, the desired timing should be about 3.5 degrees.

[rjwest]

When ( if ) you do ' TDC LEARN ' cmd,

while the cmd is enabled, the IPT will change to
the 3.5 range and the IPTD will be zero.( on the
enhanced data screen , need both screens active )

When you deactivate the cmd, the new IPTD and IPT will be displayed...

Caution, The TDCO command might reset TDCO to a value that is out of range, requiring a mechanical movement of the pump. That is what happened in my case, I was not sure if pump moved, was always set wrong, wear or I screwed up.

Anyay, if you use the commands, be prepared to move pump, IE tools , etc and courage...

try the Cylinder balance test first, gives you a feel for the program..

I'm still learning, going to drive it today at
-1.8, still not sure if I want that much advance,

[joed]

Thanks. To follow up:

Would higher altitude (I'm in Denver) have an affect on desired timing? Even at idle, my timing starts out at about 17 deg (cold engine) and then backs off to about 13 with a warm engine.

Is is possible to achieve the TDCO at different timing settings or should -1.94 TDCO always equate to 8.5 deg.?

I'm not getting any codes associated with timing, just a 1216 periodically (Fuel Sol. Response time short), which is really what I'm trying to troubleshoot.

Joe.

[rjwest]

? do not know about timing vs atmos, pressure.

Responce time to short may be injector pump.
How old is the pump,?
Do not think it has anything to do with PMD> ?

Are you within Warrenty...

[joed]

Unfortunately I'm now out of warranty - 134K. Ironically, this pump was replaced under warranty, about a year ago at 113K. It's my own fault for not pursuing it with GM sooner - the truck has never seemed to run as smooth as it did with the older IP.

One characteristic of this replacement IP which is probably related to tripping the code 1216 (albeit contrary to its definition of short response time) is my fuel solenoid response seems to generally run on the long side - around 2.0-2.2 ms. I've tried a new FSD to no avail - still get code 1216.

Is there an adjustment to the IP that can be made while still on the truck? (i.e., moving the Optical encoder slightly) Just wondering if more "tweaking" could improve operation.

Thanks again. Joe.

[rjwest]

I not that expertise in the pump, I don't think
timing has anything to do with it,
DO you use additive ? may try a heavy dose to see
if lube frees up plunger ( or what ever it is )

May want to post a specific post on the code with history ( new PMD, etc )

I had that code several times over a years time,
also symptoms of PMD fails, new PMD fixed PMD type fails but did not fix code, Finially IP started quiting when warming up, real bad,
Called Gomer, described problem, verdict, PUMP.
50K miles , no code, no fails....

Try a trace of the data to see conditions that set code, I think there should be a freeze frame in the PCM, may be interesting