Econovance Statement True OR False

[Noid93]

Just had my Vmac II checked out for a few issues like a sticky rack, truck would kill at stop signs and cut out in the middle of a light or heavy pull.

Just got pump back, need to set timing, valve cover say 6 degrees BTDC #1. And im thinking, " if i set this thing at 6 degrees BTDC, it shouldnt smoke that bad at startup like the Vmac 1 & 2 do?" What does the 20 degree econovace on the Vmac 2 do exactly. Is it all advance or does it also retard timing

Follow me and reply to confirm or deny

1)More advance gives more time for a shot of diesel to burn in the cylinder, which equals less smoke, higher cylinder pressure, less bottom end feel(torque). TRUE/FALSE

2) Less advance gives you more smoke, lower cylinder pressure, bettter "seat of the pants" feel or torque, higher EGT due to unburt fuel and less air exchage (lower rpm generally) TRUE/FALSE

3) The mack Econovance system take oil pressure to advance the timing for a smooth idle? (this causes the smoke at startup?) TRUE/FALSE

4) The Econovance system only adds to the Advance(not retarding) of the pump, (6 degrees static plus 20 Econo = up to 26 degress in the proper situations) TRUE/FALSE if false, explain

5) The static time this pump to 6 degrees, is too shallow for a clean/smoke free start up and it requires more advance to run smooth at idle. TRUE/FALSE

6) If 5 is true, the econovance adds aprox _____? degrees of advance at idle?

Thanks in Econvance

NOID93

[theakerstwo]

Is this a test?

[Noid93]

I guess I laid it out in that fashion, but no. I'm so curios as to the exact funcion of this thing, and the principles behind timing and smoke and a diesel engine.

[theakerstwo]

The econovance advances it after its started and at low load conditions like idle.

[Noid93]

So you say

1) True

2) True

3) True

4) True

5) True

6) ??????

Any idea what the static timing is on a 454 or a 427? I do have a blixxton powerbox adding a little extra fuel to this thing, and would like to time it like a higher HP engine?

[41180]

my dad built a CL glider kit a few yrs back that has a 95 vintage vmac 2 remack 427hp with a blixxton box and advanced the timing about to the max and he blew a turbo and the aftercooler not long after building it so he tuned the timing back a few degrees and it runs great now lol

[jzack]

The 427 and 454 are both 10.0 BTDC. The only difference between the two is the data file in the V-mac program.

I probably have 250,000mi on my Blixxton in my 94 E-7 350 now and I still just love it.

My guess is the Blixxton keeps the timing advanced throughout the RPM range because I notice a definite lumpy idle when I have the switch set to 30%. Idles like I have a hot cam in it, kinda cool!

While I haven't had your particular issue, I have heard that re-pinning the connector has cured similar issues as yours. I have also heard of wires shorting out on the firewall behind the washer fluid reservoir causing erratic running quality.