Timing w/o a meter

[450]

OK, I know your suppose to time the 6.2 with a meter, but what if you don't have one?. I was always taught to time a gasser by ear, hard starting or spark knock was too much, you backed it off until those conditions went away, so how about the 6.2?, most don't have a meter and it would be very inconvienent to arrange for one. (plus I had mine done and I think the guy knew less then me) so what are the signs and symptoms that there is too much or not enough? Does retarded cause high EGTs? as long as it does'nt rattle when reaching high RPMs is it OK? thoughts and opinions?

[BobND]

I use a Snap-On meter with luminosity probe on customer vehicles, but a have experimented a bit on my own "junque".

With the engine warmed up and idling, unhook the green wire from the HPCA solenoid on the IP. Connect a jumper wire to a 12 Volt source, and touch it to the tab where the HPCA wire goes, causing the timing to advance.

When the timing is set close to spec., the engine sound will go from a mild 6.2 rattle to a
"powerstroke rattle", and back to a mild 6.2 rattle when the jumper wire to the HPCA solenoid is disconnected.

If you have the timing even a little too early, when the HPCA is energized, the diesel rattle will be REALLY pronounced. If even a degree or two too late, it will sound "wimpy" when the HPCA is not activated.

That is how the engines sound, to my ear, anyway, and setting the timing this way will get it really close to spec's, when checked with the meter.

[450]

Thanks, good stuff to go on. Although it would always be nice to use a meter, it seems that most play with the setting afterward to "tweak" it to their individual motor, Which is pretty much what I've done. Had mine running at what I thought was the best it was going to be, but it also has the dreaded knock in #1 cylinder (piston or wrist pin) so I decreased it about a lines width, hoping to go easy on the motor, then it wouldn't pull, EGT's were hotter and the engine temp would spike on hills, but it was not as noisy. So I bumped it back up the line width and guess I'll take my chances and live with the noise, think its more the knock in number one then the timing too advanced unfortunetly.

[Subzilla]

Perfect timing (pun intended)! Just started playing with my timing on the '83 this weekend. I, too, have been getting excessive black smoke, high EGT's, and high engine temps. I've replaced fuel filters, air filter and had the injectors checked. I couldn't get access to a timing meter so I'm experimenting with the performance and sound. I'll try the advice from BobND - never heard of checking timing by that method but innovative measures are what the DP is all about. The only thing I'm struggling with is determining how diesel rattle is too much. Does "too much rattle" sound like the old Dodges? My '86 Blazer must have that wimpy rattle as it is fairly quiet so that's not a good comparison. Thanks for any more input.

[450]

Timing by how much it rattles is tough to do from a computer, although some here have given excellent examples, thats why I was looking for opinions on other tangible indicators, like EGTS, the way it starts, smoke amounts and color, engine temps etc, kinda like the "total package" of being correctly timed. I done some searches and get bits and pieces here and there. Thought it would be nice to get it as much in one place as possible. I've found it amazing how much change moving the pump so little makes.

[Subzilla]

I just came to that realization about pump movement! Last night I advanced the pump another line width, just one little line width. That little timing change totally eliminated the smoke at idle and further reduced the EGT's smile.gif . I'm still getting some black smoke on normal acceleration and not just under heavy acceleration like my Blazer. But it's definitly better than it was. I might try one more line width although I had the rattle coming on when I activated the HPCA as described by BobND. My next step is to turn down the IP fuel metering screw a very small increment. Cool, thanks to the DP, I'm gaining yet another chapter of diesel engine knowledge! Our goal: Maximum power, maximum economy, no wasted fuel out the exhaust!

[BobND]

Remember, the crankshaft is turning twice as fast as the IP, so a little "tweek" of the width of the timing mark, which may only change the timing from the IP's point of view by 1 or 2 degrees will be seen as double that, when viewed in the conventional fashion, as crankshaft degrees.

As you probably know, in addition to the timing chain wear issues, these IP's commonly have problems with the internal automatic advance.

The advance piston gets beat about terribly while trying to hold the cam ring in position against the action of operating the injection plungers, plus it is in the very bottom of the IP, where any and all wear particles and dirt that enter the IP settle. The advance piston wears, as does the bore it operates in.

The piston can be replaced, or the bore honed oversize, and a larger piston intalled, or the bore can even be sleeved back to standard size.

For maximum fuel economy, that advance needs to work properly, and in the real world, if there are considerable miles on the pump, the automatic advance is probably NOT working up to spec..

[Subzilla]

Driving to work today, I notice more diesel clatter under heavy acceleration but not as pronounced at idle or cruising. But the EGT's are overall lower than they were. Is this OK?

I need some more education: I'm assuming the advance increases with RPM's?? How can one tell if the advance is functioning? This pump has only about 15k miles logged on it.