timing 6.5TD'how much

[ckm]

I have a 1995 6.5 TD, had to replace injector pump,so had to have it timed by a chevy mechanic. he said stock timing is 4 degrees, what I want to know is how much timing can I run without hurting the motor? need chev mechanic to do this because of the scanner he uses to see how far he moved timing.
thanks
ckm

[britannic]

You may want to post this on the 6.5L forum. Meantime, check this post out: 6.5L Injection Timing (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004574#000000)

[sailun]

Hi, folks.
I'm on a mission to increase my fuel economy and performance.

Can someone tell me how I would go about changing the Timing Offset to this preferred -1.94 to -1.50 range ? I have access to a scanner, and am seeing my base timing at -4.0 (was -3.5, before I started fooling with it), and my offset at -0.76. Do I actually use the scanner to change the offset value ?

Also, if anyone has any tips to make accessing the passenger side mounting nut on the injection pump easier, I'd love to hear them. There's just no room to both take up the slack in the wrench, and turn the nut. I'm using 3 different wrenches, as a previous post suggested, and I'm looking for a fourth. Thinking about cutting and welding 2 together, to clear the pump body, and coolant manifold.

When I go to fix my base timing (rotating the pump), can I do this with the engine idling, or is this inviting disaster ? Or will a loose pump just give me erratic running/readings. I'm trying to avoid removing the belt and A/C every time I give the pump a nudge.

Kevin Unsworth
'97 'Burb 6.5 TD 'F', 88k miles.
Amsoil airfilter and lube oil.
pump replaced in 2002 at 23k miles.

[britannic]

For the timing parameters, post over on the 6.5L forum.

DANGER: Never adjust the IP with the engine running, the shock forces involved, approach 12000psi at the IP driveshaft.

I haven't worked on the electronic DS4 IP, so can't speak to the clearances for the pass. side nut, however, I find a gear wrench to be indispensable for turning the nuts.

[jspringator]

You have to have a special scanner that has 2 way operation. I think it is called a Tec 2. My timing was set at 0. The current setting of -1.5 was a huge improvement in power.

[Turbine Doc]

Not sure about early models but 98 & 99 can do TDC offset using display of offset and key on key off with APP pressed to the floor to do the learn.