There is nothing wrong with
the code here but if you would like to change the Closed Loop Rules here
are the locations that you would need to change in the Calibration portion
of the code. I've shown what was originally in my #3516 code set
and what I am currently running without any problems.
| Function | Memory Location | Original #3516 | Current | Notes |
|---|---|---|---|---|
| Upper RPM Limit | $F55C | 4200 RPM | 4200 RPM | |
| Lower RPM Limit | $F55D | 1850 RPM | 1500 RPM | Little lower captures Closed Loop sooner. |
| Upper MAP ADC Limit | $F55E | 6 " | 6 " | Note that this is in MAP ADC terms and NOT Manifold Vacuum as displayed by the Calibration Module. |
| Lower MAP ADC Limit | $F55F | 18 " | 22 " | Same Caution as Above ! |
The byte RPM values are in 25 RPM units, so 4200/25=168. Expect to see 168 ($A8) at $F55C and 74 ($4A) at $F55D. To get the MAP ADC value you can use the values below to get you close. Use the corrected values under L0000 and not the direct ADC readings.
; ; Vacuum Voltage ADC L0000 Manifold Vacuum ; (in) (L002a) TAIR=59 ; 0 4.55 237 240 -3.2" ; 1 4.44 231 234 -2.4" ; 2 4.32 225 228 -4.7" ; 3 4.15 216 219 -0.6" ; 4 4.00 208 211 0.2" ; 5 3.82 199 202 1.4" ; 6 3.65 190 192 2.5" ; 7 3.463 180 182 3.7" ; 8 3.302 172 174 4.7" ; 9 3.141 163 165 5.6" ; 10 2.953 154 156 6.8" ; 11 2.809 146 148 7.8" ; 12 2.632 137 139 8.8" ; 13 2.415 126 127 10.2" ; 14 2.263 118 119 11.0" ; 15 2.136 111 112 11.9" ; 16 1.954 102 103 13.0" ; 17 1.783 93 94 14.0" ; 18 1.607 84 85 15.2" ; 19 1.437 75 76 16.1" ; 20 1.238 64 65 17.4" ; 21 1.061 55 55 18.6" ; 22 .874 45 45 19.9" ; 23 .695 36 36 20.9" ; 24 .510 27 27 22.0" ; 25 .316 16 16 23.2" ; 26 .134 7 7 24.3" ; 27 .024 1 1 25.0" ; 28 .024 1 1 25.0" ; 29 .024 1 1 25.0" ;In the Edelbrock owner's manual they state that the closed loop rules for Manifold Vacuum is between 16" and 4". This is a slightly misleading because the code works off of an adjusted MAP ADC value. No MAT temperature correction is considered so as the air temperature (MAT) changes so will the apparent point that the unit will go into closed loop operation. The 16" and 4" values are close but not absolute. In fact this was the first goal I had when I started this little project was to widen out the closed loop vacuum range. Cruising down the freeway at times I could just barely pull 16" of vacuum. It was always going in and out of closed loop. Increasing the lower limit really helped. In fact I may increase it further. At these light loads you really don't need as rich of an AFR as 14.6:1 but there is so much problem with controlling the air temperature I've errored on the conservative side and programed the modifiers a little on the rich side. I am better off running around 14.6:1 closed loop than always rich open loop.