Easy as 1 2 3, Got it yesterday, pushed all projects aside! Options

[Mblizzard]

Not sure this is helpful but attached is the curve for the stock dizzy. Note that everything is show as 1/2 of the value.



This corresponds to the 123 chart of showing a max of 22 degrees advance for the 914 dizzy.

I struggled with this 22 vs 27 degrees but it makes sense as at idle your timing would have to be a certain number of degrees BTDC so the re is no need for 27 degrees of advance in the dizzy.

I would suspect that at times you are running leaner that you would like and the high octane worked with your build to keep it from pinging.

If your MPS is adjustable, I would try making it richer by loosening the inner screw alone. While this will make both the Part-Load Mixture Full-Load Mixture richer, it may have an impact on the pinging at standard advance settings. Of course, the only way to tell if it is lean is by having a AFR.

For my 2056 I found the D-jet required a good deal of change to make it run richer to get optimal performance.

[mgphoto]

Ok nothing has changed, I did nothing to the car except start it up.
Jeckell is back, took a 40+ mile run up the 14 fwy and back, not a single ping!

Outside temp is 66*F with humidity of 75%

Same Chevron gas, didn't add or change anything.

So I don't believe it is a problem with timing, I don't believe it's a problem with lean mixture.

It is definitely a problem with fuel and temperature.

This could be an issue with the Temp Sensor I or as I suspect, ambient temps above 80*F with the current Winter/Summer fuel blend.

So the 123 Ignition is so spot on it will bring all of the faults within your system to light!

[123ignitionusa]

Maybe a coil that's on its way out? Mine behaved the same as you describe. Replaced with a new one and all was well...

I would tend to agree. I chased a miss for quite some time. Even thought it was bad gas. Turned out to be the coil. Get a Bosch Blue (Brazil) not Mexico made
Ed

[BeatNavy]

I just ordered a new Bosch (Blue) coil, new plugs, and new wires. After the install this weekend, and settling (for now) on the proper advance curve setting, I am still having issues with very difficult restarts. Starts no issue when cold. But if you kill it and even try an immediate restart it's a chore (if it will start at all). I still need to verify timing on the new curve setting, but I'm hoping those new ignition components will resolve that issue.

[KELTY360]

Ok nothing has changed, I did nothing to the car except start it up.
Jeckell is back, took a 40+ mile run up the 14 fwy and back, not a single ping!

Outside temp is 66*F with humidity of 75%

Same Chevron gas, didn't add or change anything.

So I don't believe it is a problem with timing, I don't believe it's a problem with lean mixture.

It is definitely a problem with fuel and temperature.

This could be an issue with the Temp Sensor I or as I suspect, ambient temps above 80*F with the current Winter/Summer fuel blend.

So the 123 Ignition is so spot on it will bring all of the faults within your system to light!

Might want to take a look at Post #171 in this thread: Post #171

[mgphoto]

about 3 gallon of techron 91 left in the tank, took it out for a run down the 5 fwy with the wife.
72*F humidity 70% partly cloudy 24 mile run, toward the end a slight up hill, oil temps at 185*F I could hear pinging at full throttle, Hyde just poking his head out.

At this point I think I am sold on the plugged retard vacuum line, I have a pretty steady idle at 1050 rpm, headlights have an effect but not as pronounced as using the vacuum retard.

This is a '74 D-Jet so the throttle body has the single vacuum nipple, so no vacuum advance.

I am having the more pronounced "hot start" issue, my solution, at startup WOT, as she fires I reduce the peddle input but not so much to stall the engine, idle will be way to low for the first 30 seconds, so I just feather the throttle till the idle stablizes.


Also this engine has the blue coil.

[mgphoto]

Running on the last 2 gallons of the Chevron, I decided to try the Shell product Nitro+??
5 gallons, I set off on the 5 north and an instant later she is Hyde, pings no power above 3000 rpm oil temps start to rise 200*F.
Ambiant temps in Los Angeles 73*F humidity at 20%.

I was saving this test for higher temps but here goes.
I pull the connector from the Temp Sensor I in the intake plenum. Idle drops, because of the rich condition, I readjust the idle using the air screw.

I take her back out on the 210 fwy, JECKELL is BACK, up hill WOT power and no ping, I drive about 20 miles 85 to 90 mph, oil temps never cracked 190*F.

So I can see at this point that throwing fuel at the problem has an instant effect.

OK so I see and AFR meter secession in my future.