Tdco

[DA BIG ONE]

Recently replaced my IP and got a TDCO of -1.9 which is the recommended max w/phaser gears (the phaser gears have a 4 deg advance built into them), did a "foot to floor for 45sec" TDC relearn and now TDCO is @ -2.1, , is this new TDCO acceptable, or?

Timing @ idle is 10.3 act, 10.2 des, I'm guessing this is wrong, or?

[gmctd]

Still wondering where that +4deg came from?

I can show you how it could possibly occur, but is there any official word?

Important - ECT and IAT and ambient at the time of your re-LEARN event?

[DA BIG ONE]

Still wondering where that +4deg came from?

I can show you how it could possibly occur, but is there any official word?

Important - ECT and IAT and ambient at the time of your re-LEARN event?

The 4deg + came from one of the posts herein, but not in the DSG install sheet so not confirmed.

W/Phaser 1996 and newer require TDCO -1.70 to -1.90, -1.90 is what I started with, then did TDC relearn w/ECT @ 187 deg f, IAT was @ 97 deg f, ambient was 87 deg f, all @ sea level...........

[ronniejoe]

I believe that the actual increase is 2 degrees and is built into the reluctor wheel.

You should bump the pump toward the passenger side and redo the learn.

[DA BIG ONE]

I believe that the actual increase is 2 degrees and is built into the reluctor wheel.

You should bump the pump toward the passenger side and redo the learn.

RJ, I moved the ip about 2.5 mm to pass side now have IPT of 10.7 actual & 10.7 desired w/TDCO still @ -2.1 after TDC relearn at operating temp.

I'm guessing I have to bump it more, or?

[ronniejoe]

Yes, move it some more, then re-learn TDCO.

The OBD1 trucks will not show anything beyond -2.02. The OBD2 trucks will, but I don't think it is advisable to operate there.

[DA BIG ONE]

RJ: I did a relearn through carcode the TDCO is now -1.7 w/IPT @ 10.7 got this new TDCO w/o bumping pump more.

[ronniejoe]

OK. There are several possible Offset numbers available for each pump location. The scanner should cycle through different available settings during the learn procedure. When you see the number you want, simply stop the procedure and let it "learn" that value. If you don't see the number you want, you must move the pump and try again.

If you're happy with -1.7, then call it good and be done.

[DA BIG ONE]

Can only get TDCO of -1.5, I'm guessing bumping the IP back and looking for better value.

[gmctd]

The ko-ko routine actually calculated the correct value for the position of the IP - you can use the scanner to find a new value, but best bet is probably to rotate the IP just a hair to the passenger-side, lock it, do the ko-ko thingy to get the value for the new positon.

If the value is low with the scanner, increase, rpm a little till you see the desired number, exit TDCO LEARN to lock that value.

Appears as tho the IP is a little too advanced, at this point - the temperatures indicate PCM should not be calling for any advance, so the ko-ko routine gave the most accurate value.

If PCM is DESIRING advance, the numbers will be skewed in TDCO LEARN - important that ECT and IAT be at normal operating range, which they were.

[ronniejoe]

It can be frustrating, but don't give up on it. You'll eventually get the numbers you want. I would use the scanner method. Did you ever see numbers cycle?

[DA BIG ONE]

Numbers did cycle, best i could get is TDCO OF 1.7 but no minus sign now thinking this maybe + 1.7

[ronniejoe]

That would mean that the pump has been moved too far. Move it back toward the driver's side.

Did you see the negative sign in previous attempts?

[DA BIG ONE]

I bumped the IP back and now have TDCO set @ -1.7.

Had called vendor of carcode and he said there is no + sign in the software only -.

Carcode TDCO learn dose not open always so have to click on enable a few times to get it to open, I did not know this before so most probably the enable window did not open at times.

[rjwest]

I had the same problem setting my TDCO,
I found that clearing the TDCO with the key on/off routine, than checking
the car code tdco for a value of zero, ( tdco in reset state in PCM )
removed all the ambiguity of the process,

Than let the PCM set TDCO, I could here it set, TDCO very repeatable
this method...

[DA BIG ONE]

I had finally got the code for IP timing issue, snugged up pump, adjusted it and got the reading I wanted, tightened it down then cleared the codes, ok now!

Learning curve here!

I want to thank all of you for the input..................