VR related info for MembersPage/EricN/Trigger


MAR 06/2006

Tried "try a 40..100k pullup (to 5V) on the VR signal (100k between EC36-pin27 and EC36pin29)." used a 100k resister between pin27 and 29, no diferent. Tried the 40k, a little better but nothing worth getting overly excited about. Just to double check, I DID NOT do one (resistor) to gnd at all, just jumped pin 27 and 29 with the resister, is that correct?

Also got frustrated and built a new 12-1 wheel using a ford sensor. Carved the missing tooth area to get the amplitude perfect (.5 v lower than the rest at 8v), made a slight difference at higher rpm (1200) but again, still has the same problem.

Hacked ofF the diodes by the input jumpers on the bottom of the board.

Nothing seems to be making any notable difference with the vr sensor.

Set distributer up with a drill on test bench. No gnd or gnd 5 loads other than fuel pump relay grounded by an injfet and the vr sensor to gnd. Still have 4 gnd5 wires and 1 gnd wire in test harness. Spin drill between 100 rpm all the way up to 1500 rpm, trigger drop out no different than when ecu is in the truck. Changed from multitooth to coil type trigger, 24 teeth and used a good, straight stock honda distributer on the end of the drill. Problem still the same. Used the 4 tooth part, set the tooth count to 4 and try again, thinking if the teeth were too close together on 24 it could cause a problem, it is ALOT worse when set up as a 4 cyl. Problem definately has to be either on the board or in my config. Messed around alot with the config settings, unable to make the problem any better.

Going to try and de-solder the diode from the bottom of the board that I soldered on (d27???), said it was optional, not sure what it does. If it protects something I dont care, I am so beyond caring about frying anything anymore.


Take pic of bottom of board.

Thought my broken gnd wire was going to be it. Just as bad as ever after wiring and ecu repaired, back to the drawing board.

Now that I have the RPM constant set right, the thing idles excellent (maybe ign idle control is working) but the trigger drops out way more than before (I can barely get it to start).

Replaced all my ground cables, added some new ones. The best I can manage is about 1100rpm safely, much lower than that and it will for sure start acting up. Here is a [pic of my board].

Another issue that I think is related, if I hit any part of the engine with a tool I can make the ecu trigger. The closer I get to the distributer, the less force I need to do it. I need just to lightly touch the distributer with a tool and it fires away.

Also drove the truck today just for the heck of it. The problem actually happens at almost any rpm, it just isnt as noticeable when you are free revving the motor, add a load though, all hell breaks loose.


The full config is MembersPage/EricN/Config


The VR trigger is killing me, I have tried many things, even shorted pin 5 and 8 on the LM1815. It definitely worked a little better, but I still get the same dropouts.

  • Stuck the distributer in the lathe, cut out all the runout. I now go from a highest peak of 7.4v to a lowest peak of 6.9v and it is not around the missing tooth. Even now, it still cuts out.


Started over with input trigger ideas. Took a VR sensor and 24 tooth trigger wheel out of a Honda Civic distributer. Ground off 1 tooth, pressed it on to a gutted Unimog distributer (took the whole advance mechanism out). Welded a plate inside, mounted the VR sensor on the plate. Now I have a 24-1 trigger wheel driven by the cam.


If I see right, this wheel is very prone to output bad signal at the missing tooth. If you can, record it with a soundcard. To be safe, divide by 50 (or so) using a 100k and a 2k (or so around) resistor. It might output just higher amplitude signal at the missing tooth, or maybe it has a ghost pulse too.

When cranking, I notice that every now and then the rpm dies off to zero for the same half second then comes back. Likely trigger signal shape problem.

If I touch the body of the distributer with a wrench (vr sensor in distributer is my primary input trigger) while the key is on but car is not running, it triggers the ecu and injectors and coils fire a quick shot.

  • try a 40..100k pullup (to 5V) on the VR signal (100k between EC36-pin27 and EC36pin29). This raises the noise threshold (good), and unfortunately the minimum necessary signal needed to trigger (bad). If you measure the smallest signal amplitude (eg. with notebook soundcard, and 2 resistors to divide, see ElectronicDesign/TriggerSignalGenerator) that still triggers, you won't be bitten by "cannot start" problems as the weather gets cold and battery weak.
  • If you have a v3.2 or older, a 150k (or 100..220k) resistor in series with C38 might help. See InputTrigger/RunOut . This should be able to pushe down adaptive hysteresis threshold under 65%. TRIED IT, DIDNT WORK, HELPED A LITTLE

You might also want to capture (in TerminalProgram) the output of Manmdkffmdfff command, especially around the strange behaviour. You can switch off the continuous output by mdf00 or reboot. Captured it, it is all in hex, I see I have to do some perl stuff to make it readable but cant make it work

Here it is

64 20 76 9A 79 A6 7F C6 86 25 8C F4 9D 8B A1 CF 
B5 6E D5 9C D8 B3 FA 14 03 5E 21 D6 2A C4 3F 32 
4F D2 85 77 C6 F8 D0 51 0A 16 16 BF AB 6E BA 2A 
C3 3F E9 33 0E 34 19 2C 6D A1 76 26 E1 04 E9 58 
F3 48 F4 8F F5 EC F7 4F F8 A0 F9 CA FB 15 FD 99 
FE 89 FF E5 01 7B 02 FD 04 60 05 C0 07 C4 0A 95 
0E C3 0F F7 11 5B 14 D7 22 0E 4D A1 73 FB A5 20 
E5 31 0B 60 28 73 47 38 6B 68 8A 6D A4 D0 C0 60 
FC F8 15 F2 30 68 4E FA 6A 9C 83 99 9D 7E BA CA 
D3 83 E4 03 F2 92 01 30 0F 73 1D 97 2C B7 3D 74 
4D 5E 5D 2C 6D D9 7F 51 90 DD A2 4A B4 14 DB 1F 
ED F2 01 B4 17 12 2C 57 41 23 56 BA 6E 3D 85 2E 
9B 5C B2 A9 CC 14 E4 DA FC 90 15 DB 32 67 4D 0F 
66 15 80 2E 9C DD B7 F7 D1 5D EB BA 25 77 3F 5F 
5A 9D 79 92 96 45 B0 A3 CB F9 EA 95 07 0B 20 C0 
3B E8 5A 25 76 67 90 A5 AC FB CD 21 EA 66 04 D1 
20 63 3F 31 5B D3 75 AD 90 9C CB B7 E5 9A 00 FD 
20 48 3D 32 57 75 72 99 91 16 AB 95 BE 40 CF 38 
E0 E6 F2 4F 03 28 15 06 28 8C 39 30 46 12 51 FF 
5D FD 69 CC 75 93 81 C1 9C 16 A7 7A B2 45 BD 34 
C7 FE D2 EE DE 25 E9 E9 F5 D5 01 D5 0E 16 1A B7 
26 CC 31 E4 3C B0 47 AF 52 A2 5D A8 69 12 74 FA 
80 E3 8B E6 96 7E AC 3E B7 05 C1 E2 CC E8 D7 C6 
E2 2B EC 26 F6 37 00 47 0A 4C 14 44 1E 4D 28 52 
32 65 3C CE 47 9F 52 75 5D 46 68 5D 73 CB 7F 3A 
8A 97 95 A4 AC 6B B7 D0 C3 8F CF 73 DB 7C E7 56 
F2 E2 FE 9A 0A 5B 16 43 22 9E 2F 36 3B C6 47 BB 
53 75 5F 97 6B B7 77 FB 84 94 91 4A 9D DC AA 74 
B7 41 D2 28 DE F0 EB AD F8 A8 05 AE 12 FE 20 53 
2E 53 3C 59 49 EB 57 22 64 86 71 F4 7F 78 8D 44 
9B 59 A9 8B B7 C4 C6 71 D5 C9 E5 4F F4 93 03 81 
22 20 31 48 41 0C 51 AB 62 94 73 B0 85 6F 98 3E 
AB 68 BF 41 D5 3D EE 7B 09 79 26 F7 4D 68 AD 28 
BF 47 CB 11 D0 74 DB 6A E0 B9 E6 86 F8 A5 FE E7 
04 F1 15 4B 1B 26 27 67 2D 2B 3E 08 42 30 71 CA 
82 00 87 6F 8C 9C 9D A7 B3 09 BE 04 C3 6A C8 4E 
D8 AE ED FA F3 5C F8 76 08 FB 1E E4 2E B5 3B 02 
40 56 45 6D 5F 86 6D 6F 77 76 8C 0C A4 62 A9 49 
B7 81 BC 5D C0 CC C5 42 D3 19 D8 06 DC DF EC 84 
F6 14 FB 45 1D 5B 22 43 27 1C 30 27 43 19 63 91 
6C 5F 75 7C 7E 5D 83 03 87 BD 8C 56 9A 2D 9F 34 
C6 6A CA 8C D8 18 E0 BD E5 17 E9 E6 EE 80 F7 BE 
FC 7C 00 F8 05 B4 14 32 19 98 23 ED 31 3A 43 74 
54 44 69 30 86 1B 8E AF 9A 7D 9E 3F C6 6F CA 85 
CE CA D3 3C DB F6 E4 C6 E8 DB F5 B7 01 F0 06 03 
0A 00 0D E7 11 C7 16 3F 1A C9 1F 72 28 35 2C B2 
35 22 69 3E 6D 80 70 FD 74 86 89 01 8C B2 98 C7 
9C AA A0 81 A4 6C A8 9C B4 79 B8 9E 

With the engine running, mda28 will force 10 crankdegrees advance, that is decimal 40 * 0.25 degrees; mda01 forces 0.25 degrees advance, mda00 restores normal advance calculation; see refcard on GenBoard/MenuSystem) and pointed my timing light at the crank, adjusted the distributer till #1 was firing dead on tdc.