Timing question

in the process of installing new injectors, figured I should time time the injection pump. Should I wait till the new injectors are in to time it or should I just go ahead and time it to 8 degrees BTDC? I heard this is the sweet spot for these trucks. It's pretty much at factory mark, if not 2-3 degrees BTDC. Just wondering because all the hard fuel lines are disconnected so it would make it easier to adjust.

Different pop pressure output means different timing. It is best to time with the injectors that you are going to run.

The above statement is true. The timing may be a bit different with the new injectors.

More importantly, the engine must be running in order to time it. You stated that the hard lines are all disconnected. You'll find it quite difficult to run the engine that way. So, put in the new injectors and attach all hard lines. Time the engine running with a proper meter.

I'm talking about static timing guys. without the timing light. I was just going to move the pump 8 degrees becaused I heard it was the sweet spot for most idis.

I just want to get a little more power out of it

I see no way to "static time" the pump. Also using a light is not going to be as satisfactory as using a Kent Moore J33300 meter. These meters will break down a degree of timing to a tenth of a degree. You just can't do that with a timing light. the j33300 meter has a micro processor that does the timing and the rpm for you. All you do is clean 2 locations. connect 2 probes. Power up the meter off any battery. then press one rocker switch and then start engine. Rev to 2000 rpm and watch the rpm and timing on the meter..Done. Then... And only then shut off the engine to adjust timing NEVER attempt to adjust the running injection pump. Doing it so may break the pump main shaft is you slip and the pump crashes on the adjustment stops. then the pump is worthless and no core charge.
And this is a final note. As already posted. Every replacement injector pops at a different pressure and that decides timing. Be careful purchasing ANY pumps or injectors. Most ebay pumps and injectors are not very trustworthy. This forum knows who sells the best and can advise you.
Finally those marks you feel are the correct degrees of timing to static set by.. Well once they were but that was a factory installed pump. Pumps can't be timed internally to match what the factory pump was. So those marks are essencially useless.i

Oregon fuel injection suggest that for turbo'd 7.3 should be set to 5-6 degrees instead of 8.5, and justin at r and d also suggested 6 degrees as well. His stage 1 injectors run quite well and the price is good! He also offers stock ones that cost a little less but still do the job well! You can try to time it by ear but it is rather difficult lots of trial and error but can be done by some, I did mine by ear I was hoping for 6 degrees an when I decided to take it in to Oregon fuel injection they said I set it to 8 degrees. So timing by ear like 4 times got me to be 2 degrees off where I wanted to be but really isn't that bad for just guessing essentially

Alright I guess ill buy the meter to just be sure!

My timing meter rental is 70 bucks for 5 days. You get my cell number for questions. All the factory tools and.. All the simple directions. I pay the flat rate shipping of around 13 bucks in your direction and you only pay the one way same back to me when you return the meter.. Ask around about my service. I don't do this as a living. I try to cover my costs of keeping the meters operational. Some ******* in the past broke my mag probe. Taped it up with blue electrical tape. then shipped it to the next member on the list. It did not work when that member received it so who to blame.. I blamed myself for trusting people.. Now it COMES home no matter what. Even if it takes 6 days to return from the east coast and get back to an eastern state. A couple of turds ruined the trust for everyone. BTW I test EVERY meter on my rig before it goes back out. So you will get a working meter no issues...EVER...

Just to reiterate, static timing is static timing with the exception that some of the reground cams call for a change in cam gear position relative to the marks. That's the only static timing you get. Everything else is dynamic and rpm is important. There is an internal advance curve that is rpm dependent.

Basically, what everyone else has said. Status timing is just to get the engine /running/; to get it running /well/ requires adjustments.
Each pump is slightly different, and pop pressures do affect it by a significant amount. A couple of degrees is the difference between a clattery hard-to-rev engine, and a smoother, more powerful and more fuel efficient engine.

Also, as far as I'm concerned, the nominal degrees(8 degrees NA, 6 degrees with a turbo) are good if you've got a new pump.

If you are reusing a worn pump, well, it's a /start/ at best. Mainly because the internal timing piston wears and will give you a different timing curve; you can work around it to some extent by messing with the light load advance cam, and adjusting base timing based on how the engine runs.
The problem is that the actual timing curve is a 3 factor curve involving RPM, fueling, and throttle position(due to the light load cam)... and once the internals wear a bit, it changes unpredictably.

In your case, as you aren't replacing your pump, I suggest that after you time it to 6 or 8 degrees, see how it runs. Then advance it 2 degrees and see how it does. Better or worse. If worse, retard 2 degrees and keep doing this until it feels the 'best'.
Note that you may end up with something where it feels "good" in the low end, but "off"(either clattery or smokes white) at the high end. Or vice versa.
I always aim for the mid range to top(loaded, accelerating) to feel the best, then adjust the light load advance cam to fix the low end.

thanks for your help, I just installed the injectors last night and return lines and fired her up. the idle is really rough now and lacking power. almost a slight knock to it. i believe It is the timing from what you guys said. hard to rev up and clattery. I don't even want to drive it like this. I didn't think the injectors would make this much of a difference.

...So retard it a bit(a dime's width is a good starting point) and go from there.

Macrobb said:

...So retard it a bit(a dime's width is a good starting point) and go from there.

Click to expand...

just to help add clarity to this statement ^ that would be a dimes thickness.timing adjustments are so slight,that you can actually change a degree, simply by fully snugging up the nuts.

Every engine is different. Mel and I played with my old 94 with banks turbo, moose pump and bob code injectors. Found best hp/tq numbers at 9.5 degrees. At 8 degrees it made decent power, gained 20-30 ft lbs and 15 hp at 9.5, and lost 20 hp at 10.5 degrees. Torque stayed the same. I set every pump I time, turbo or not, to 9-9.5 degrees. Factory spec is 8 degrees +/- 2 degrees. But that also depends of the cetane rating of the fuel. A truck running WMO will want different timing than a diesel burning unit.