Timing by sound?

[Joe Mc]

I wrote in one time that I paid $86 to have mine timed, someone from NC wrote that they paid around $40, but I can't find the post now.

 

[zigg]

I personally don't see a problem backing off timing to reduce noise. After I got my wrecker I backed off the timing and it is much more driveable now.

Where you get in trouble with timing by ear is with overadvanced timing. I think people get into the "If some is good, more is better" mentality.

This is very true, however, if your timing is retarded even a little, you'll get less and less efficient the further retarded you go, and you're wasting fuel. It's not unlike having the fuel turned way up, and watching the ********* cloud of unburned fuel rolling out the back. Course, if you can afford it, pro'ly doesn't hurt the engine too much.

I would assume that could be the case with these motors as well.

Consider that each injector pops at a different pressure as they wear, so if one pops at a lower pressure, it will open and spray fuel before another which requires a higher pressure (later in the rotation of the injection pump) to spray fuel. So, having said that, each cylinder will effectively be running at a different timing than the others, especially on very worn pumps and injectors. So, timing is more of an "average" of all of them. Since the timing is set on #1 usually, this is assuming the rest are similar.

So, I'd say you're probably right. There's probably a "happy place" for each engine depending on it's age and condition of the parts.

On my old engine(over 300,000) I backed the timing off about 2 degrees from the stock setting, and it's way happier, 'specially with the lpg on. I get over 20 mpg most of the time, so I'm quite happy with it. Only down side is the fact that it's now using about a quart of oil every 300mi or so

 

[Diesel JD]

From what I hear the LPG fumigation means that you need to retard the timing a bit. I am running around witha static timed engine,a dn I'm not totally happy with the fuel economy I'm getting. Since the fuel is homemade biodiesel and cheap/clean anyway, I'm not in too big a hurry toget it fixed. When I get some time, all the injectors are getting pop tested, new returns and I will pay to have the pump timed once that turbo is on and operational!

 

[sle2115]

What's a guy to do? Come to the IDI Weekend in southeastern Indiana next July, that's what.

Would love to do that, but you of all people know how busy a fellow can be - PhD studies are kicking my tail at the moment, but I plan to take next summer off anyway, I need a break. I have been a re-born student since fall 1999, so I think a quarter off and a trip to Indiana might be in the making. Course next year I will be seriously working on our new house as well...

 

[NapaBavarian]

using about a quart of oil every 300mi or so

Look at the bright side, that's 1200 MPG on your oil

 

[NapaBavarian]

How about what direction to advance the timing, does rotating the top of the IP to the drivers side advance or retard?

 

[tuke]

How about what direction to advance the timing, does rotating the top of the IP to the drivers side advance or retard?

Passenger side advance, drivers will retards the timing. I'd only move it a small amount 1/16" one way or another.

 

[NapaBavarian]

That is easy to remember, I'll just remember that all drivers are retarded thanks!

 

[Diezel_Cowboy]

This weekend SmokinStroker and I got to borrow a diesel timing unit. We checked both his 6.9 and my 7.3 turbo. His was within book specs but mine was 5 degrees off of what we could figure was specs (the books we had either didnt metion the 94 turbo or they didnt agree). We shot for 8.5 degrees BTDC. Is that the correct timing specification for the 7.3 factory turbo?
After setting the truck to around 8.5-9.0 degrees BTDC at 2000 RPM we went for a test drive, seemed to have more power and boost seemed to build faster, as well as EGT's climbing faster. The only other noticeable effect is that the motor has a louder "diesel" sound when it is cold.
Is it better for the truck timing to be a little advanced or a little retarded?

 

[Agnem]

All flavors of our IDI are timed to 8.5 BTDC at 2000. The luminosity method is the one most indicated for the 6.9, because the equipment to time it with the pulse method wasn't available when they were first produced. And it doesn't matter if it has a turbo or not. Your description of your findings and subsequent improvements is pretty typical. I'd say you did it right. They say within 2 degrees of 8.5 is fine, but I like to be within a half a degree either way. When you get up around 10 to 10.5 degrees, not only is it pretty loud, but the glow plugs can start to errode, so if your going to error, error on the retarded side.

 

[Diezel_Cowboy]

Mel,
The pump took quite a bit of arm strength to turn with some big *** channel lock pliers. We coordinated the tweeking and meter watching between the two of us. We got it up around 8.5-9.0 when we tightened the pump bolts up to hold'er in place. So it may be possible that it is 9.0 or 9.5 but if i gather what you are saying correctly then it should be within specs. She really rattles now! By the way I dont know if i mentioned it or not, but the before adjustment reading at 2000 RPM's was around 3.0-3.3 degrees BTDC!
Thanks for backing that information up, none of the books we had made very good mention of the 7.3L with turbo.

We also used the pulse hookup for SmokinStroker's 6.9, but the book that came with the meter said that it should be checked at 1400 rpm's not 2000.