How do you know if you've advanced timing too far?

[Oblin Goblin]

Just wondering how I would know if I've advanced the timing too far without using some kind of timing tool. I recently advanced the timing on my Blazer a little, the mark on the pump is now about 1/8" to the drivers side of the one on the engine, before it was about 1/16" to the drivers side. Fuel milage is up about 1-1.5 mpg and it starts better, which I really like, but it doesn't run quite as smooth as before, and it smokes a little more, especially off idle. Once the rpms pick up the smoke goes away, but I'm seeing a lot more "invisible smoke" at all rpms. You know the smoke you can only see in the headlights of the car behind you at night? Before I advanced the timing I would seldom see any smoke, visible or invisible except at higher rpms, 2700+. So I'm wondering if these might be indicators that I've gone too far. Any thoughts? This is in an '84 6.2 Blazer with a Banks turbo and 260k miles, original timing chain

[Peter J. Bierman]

A trained ear can tell more or less if timing is right.
The distinguish sound called the diesel rattle gets louder when timing advances, that explains why it's louder now.
If the engine starts to sound like a powerstroke when warm, you are way to far advanced.
If powerstroke sounds are present on a cold start and getting to "normal" when the HPCA disengages during warming up, you are about right.

If you do not have a trained ear, the only way is checking with a timing device, which is recomended any way to be sure.

Peter

[TanM998]

smoke....

at different levels of timing your engine will smoke differently... if your engine is still naturally asperated, when you stop on the throttle there should be a cloud of black smoke clearing up to clear smoke. If the smoke is any other color then black (such as white) or if it doesn't clear up, then its not timed right.

The BEST way to ensure the engine is timied correctly is to spend $100 at a local shop and have them time it correctly for you....

Scott
'85 Tan M998 W/CTIS