too much timing?

[Cowracer]

I am genrally pleased with the overall performance of the new engine (grunt, grunt!) but the installer set the timing at -1.94.

I know this it the sweet spot for power, but it just sounds a bit too rattle-y for me. Especially when just maintaining speed on the flat. I have visions of my wrist pins getting beat to death.

So I want to de-time it just a hair to about
-1.50 or so, but I dont have any kind of scanner.

Knowing that I started at -1.94, can I just move the pump a bit to retard it a touch? Or do I have to redo the TDC Learn? if I do, is there a way to force a tdc learn on an ODB I truck without a scanner?

I understand lots about 6.5's but the TDC Offset thing still leaves me puzzled, even after reading everthing I can on it.

Thanks!
Tim

[JohnC]

Simply moving the pump will not accomplish anything. The PCM still knows where the pump is in its cycle relative to where the crank is and adjusts timing accordingly. I believe this is to allow the PCM to compensate for wear in the timing components.

The reluctor wheel for the timing gear set is advanced relative to the factory one, in effect tricking the PCM. This may be ahy the rattle is a lot more pronounced.

There is no way I know of to get an ODB I truck to relearn the TDC offset without a Tech I/II

[charliepeterson]

Unfortuneately you will need a Tech II to re-time the engine. Before you move the IP take a real close look at where the timing mark is because you will only move it the width of a hair to the right side.

[Barry Nave]

TDC Offset thing still leaves me puzzled.

Cowracer
With the gear and TDC,I now have 5yrs with 67K with this set up. 80K on new long block.
Cold start does rattle but settles down when warm. More so when really COLD start. There seems to be a rpm range around 1800-1900(no load) that rattles more so than below or above. Power is way up then when I first got truck that was stock. Mileage is good,also better than stock for the way the truck is set up.(Bed rail tool box's)
Really not sure if there is a sweet spot when it comes to TDC learn. The 94-95 seems to like the -1.95 and newer modles have gone up to 2+ with out setting codes.
I did try setting with a base timing of 8deg. before doing TDC offset learn but PCM would not take it with out code.
Tried this only because one member said it worked,not sure who this was? To long ago ;)
I say don't worry ;)

[eracers999]

Tim, TDC offset learn -1.10 to -1.24 is where the destructive rattle becomes acceptable, will run cooler in a pull too. Tech 1 will do complete timing procedure on your 94 to 95.

Kent

[rjwest]

QUESTION: What is sequence for setting TDCO and Timing. Do you do TDCO learn before or after doing Inj Pump timing cmnd ????

[eracers999]

Timing first, then do TDC offset learn.