Itinerant Air-Cooled

whc03grady wrote:Man, those valves were so all over the place that I'm pretty convinced that was the trouble all by itself. WaterDawg dialed them all in--his first time--and the bus seems to be running pretty well. I'll let him fill y'all in though, it's his story after all.

Bleyseng wrote:If the Aux battery drains down the main battery then you must have the relay wired wrong or its fried.

WaterDawg wrote:

Bleyseng wrote:If the Aux battery drains down the main battery then you must have the relay wired wrong or its fried.

I check Post 88. She has 1.1v switch on and .1 switch off.

Got to check to see if she is stuck open, but need to figure out the setting on the voltmeter for that BRB

Amskeptic wrote:

whc03grady wrote:When checking for vac leaks with GumOut, how much are we spraying here? I'm reticent to burn down anyone's bus except my own so maybe I had too light a touch, but I didn't notice any change in running and I think I hit all the vac connections.

One intake runner boot was loose enough to turn by hand so we put clamps on it for good measure. It idles near perfectly if you disconnect the little tube from the decel valve. Does this indicate a rich condition? I'm extremely hesitant to mess with the mixture. Oh, hitting the brakes kicks up the idle too, at least for a second.

Anyway, this bus is overdue by at least 1,000 miles for a valve adjustment so I'll be talking Larry through that tomorrow morning. Then we'll look at the points.

Yes, rich due to high elevation, decel valve gave it away.

Be bold! Just NOTE your initial adjustment settings.
For example, with engine off, turn the mixture screw in the AFM clockwise all the way down until it stops. Record how many turns to the prrecise fraction. Now turn it back to where it was.
Since it is rrrich, take another two or three turns counter-clockwise. Test drive.

Now Waterdawg, be CAREFUL with the following FACT . . . .
When you drop below 3,000 feet down on toward sea level, you must be ready to re-richen the mixture. Use the decel small hose as your reference hose.

That now-called Reference Hose also removes the vacuum to the fuel pressure regulator, making it increase fuel pressure. That means you must understand the bias that is introduced when you pull the hose.
The bias is : slightly rich!
You must allow your mixture adjustment to end up "slightly rich" as in a "mild increase in idle" as you take your finger tip off the reference hose. WHEN you put the hose back on the decel valve, the fuel pressure regulator will respond to the vacuum by dropping the fuel pressure, which leans the mixture to "perfect".

Feel free! to turn the black cog wheel teeth inside the AFM cover CLOCKWISE up to six clicks (after you paint an initial setting point!)
to lean it a bit more as necessary if engine is boggy out on the road.

Keep an eye on the CHT gauge, I am glad you have one. Lean is more deadly than rich.
Here is a quicky check anytime.
At a stop, lightly pump the brake pedal quicklyquickly.
If idle drops dramatically - too lean
If idle goes up ridiculously - too rich
If idle drops mildly and recovers when you stop pumping the brake pedal lightly and quicklyquickly - just right

You are HEREBY NOTIFIED that if any drop in power occurs on the road YOU MUST INVESTIGATE IMMEDIATELY, no rationalizations about making it to the next exit.

I'll check in tomorrow, November 14th around 8:00PM . . .
ColinLexusOldManOnTheRoadToMiami

Keep an eye on the CHT gauge, I am glad you have one. Lean is more deadly than rich.
Here is a quicky check anytime.
At a stop, lightly pump the brake pedal quicklyquickly.
If idle drops dramatically - too lean
If idle goes up ridiculously - too rich
If idle drops mildly and recovers when you stop pumping the brake pedal lightly and quicklyquickly - just right

whc03grady wrote:Just take them off carefully. If you feel the gasket is sticking to the head and might tear, back off and fight another day.

WaterDawg wrote: all exhaust valves tight
all to .006 now.

timing set to 24-28 BTDC at 3400 RPM. (idle 0*)

hesitation under throttle could the timing be at issue here?
I'm getting little to no change if I pull the vacuum line though....
slightly under powered up big hills,

holding a fast idle. If I lower it too much (950) she idles very erratic.

Amskeptic wrote:

WaterDawg wrote: all exhaust valves tight
all to .006 now.

timing set to 24-28 BTDC at 3400 RPM. (idle 0*)

hesitation under throttle could the timing be at issue here?
I'm getting little to no change if I pull the vacuum line though....
slightly under powered up big hills,

holding a fast idle. If I lower it too much (950) she idles very erratic.

Time for us to be scientific, Dawg, yo yo yo Dawg here's the thing . . . (I am channeling Randy Jackson)

You are the boss, you are the scientist.
a) do not expect a change in uphill performance when you take the vacuum advance hose off the distributor. There is no vacuum going up a hill anyway . . .

(for fun, please set the timing up a bit, yes, we want a little more idle timing please, try for 3* BTDC after you actually adjust the timing at 3,400 rpm to let's say 28* on the dot)

b) an engine that cannot idle correctly at 950 rpm has a problem. Set the idle to whatever allows you to get back to the engine compartment. Once there, reduce the idle until engine begins to protest. Now put your hand on the wiper in the AFM, and ask the engine what it wants.

If it "desperately" wants more gas at idle and recovers from your above stated idle rpm wandering, either you accidentally overadjusted the AFM to weird places, or you have an as-yet unidentified vacuum leak or sumpin'.
Colin

Again, *make the engine get into the unhappy zone*. *Ask it if wants more or less fuel*. If it wants more, it will begin to idle at 950 nicely. Remember, we can adjust the fuel mixture at idle AND we can the opposite direction at high rpm should we choose to.

WaterDawg wrote:

Amskeptic wrote: Again, *make the engine get into the unhappy zone*. *Ask it if wants more or less fuel*.

On the dot huh
there is no way for me to be on the dot (youtube)

if I did anything to the Idle Mixture Screw, there was no reaction from the engine.

Amskeptic wrote:

WaterDawg wrote:

Amskeptic wrote: Again, *make the engine get into the unhappy zone*. *Ask it if wants more or less fuel*.

On the dot huh
there is no way for me to be on the dot (youtube)

if I did anything to the Idle Mixture Screw, there was no reaction from the engine.

Some of that erratic flashing of the strobe can be attributed to the timing light not picking up the signal. Place the pick-up near #1 spark plug away from the other wires. Make sure all wires are not crossing each other and "cross-talking". Some pick-ups have a little arrow embossed in the plastic, it should face the spark plug.

Scatter (where it is flashing consistently but all over the place) can be attributed to crankshaft endplay and a little bit of distributor drive gear lash, just work around it, average out the readings . . . relax.

Idle mixture screw was not the experiment here. When the engine is running poorly down at idle, move the wiper either counter-clockwise or clockwise no more than 1/4" and let me know how IT affects the idle quality.
Colin