Search found 95 matches
- Tue Jun 15, 2010 3:15 am
- Forum: Installation
- Topic: How does MJ know which time around?
- Replies: 2
- Views: 2538
- Mon Jun 07, 2010 4:37 am
- Forum: Future Upgrades
- Topic: Ignition system with repetitive sparks
- Replies: 26
- Views: 56555
- Fri Jun 04, 2010 8:29 pm
- Forum: Operation
- Topic: plug wire cylinder# question
- Replies: 3
- Views: 3590
- Thu Jun 03, 2010 2:24 pm
- Forum: Operation
- Topic: Aux input (voltage to input) Megajolt v4 jr
- Replies: 14
- Views: 14320
Voltage Divider
That will work. But then there is still the problem of generating a calibration chart for the original gauge-sensor combination, how do you do that? Also, 12V to the gauge varies a lot from say, idle with lights on, to full speed no load. That voltage variation will cause the MJLJ gauge to change ev...
- Fri May 28, 2010 8:14 pm
- Forum: Q&A
- Topic: 3 cylinder application
- Replies: 2
- Views: 3110
More Detail
An even fire 3 is like a 6 with half the cylinders missing. It takes 2 turns, 720 degrees to hit everything. At zero degrees, 1st coil fires your first cylinder in the firing order. At 120 degrees, 2nd coil waste fires the 3rd cylinder in your firing order. At 240 degrees, the 3rd coil fires the 2nd...
- Fri May 28, 2010 6:49 pm
- Forum: Q&A
- Topic: 3 cylinder application
- Replies: 2
- Views: 3110
3 cylinders
Basically think of it as a 6 cylinder engine with the even cylinders missing. You have cylinders 1,3, & 5, so 2, 4, & 6 are missing. Wire it up with an EDIS 6 coil pack (3 coils). The second wire on each coil output is grounded to complete that circuit. Bruce Roe
- Tue May 25, 2010 2:58 am
- Forum: Operation
- Topic: Understanding Advance Correction?
- Replies: 5
- Views: 7243
It can also be used as a tuning aid. I connected a 2K variable resistor. With the internal 2.2K pullup, voltage varies from 0 to nearly 2.5V. That in turn is translated to -12 degrees at 0 ohms, 0 degrees at 1K ohms, and +12 degrees at 2K ohms. Voltage isn't linear, but the translation table fixes t...
- Thu May 20, 2010 2:13 am
- Forum: Operation
- Topic: Aux input (voltage to input) Megajolt v4 jr
- Replies: 14
- Views: 14320
If I had your email, I could send the conversion table as a .txt file. For some reason, my APPLE doesn't like to deal with .txt files. Or brentp can make it available. Here is my translation from temperature degrees F to voltage into MJLJ, with a 2200 ohm pullup resistor to 5.00V. This circuit is sh...
- Wed May 19, 2010 10:39 pm
- Forum: Operation
- Topic: Aux input (voltage to input) Megajolt v4 jr
- Replies: 14
- Views: 14320
Here is the generic temp sensor with resistance every 5 deg C; thats every 9 deg F. I figured the voltage with a 5V source through the MJLJ 2200 ohm series resistor every 9 deg F, extrapolated between. Below is MJLJ conversion table. Bruce Roe http://www.pe-ltd.com/Downloads%5Ccoolant_temp.pdf 255 2...
- Wed May 19, 2010 3:02 am
- Forum: Operation
- Topic: Aux input (voltage to input) Megajolt v4 jr
- Replies: 14
- Views: 14320
If you use your present sensor (which NEVER exceeds 5V), you will have to measure the voltage and temperature (trust your original gauge?) over the operating range. Then make a conversion table for the MJLJ. Without a conversion chart the MJLJ gauge will apparently be reading backward. And disconnec...
- Tue May 18, 2010 6:25 pm
- Forum: Operation
- Topic: Aux input (voltage to input) Megajolt v4 jr
- Replies: 14
- Views: 14320
Temp Sensor
That would NOT be OK, for a couple of reasons. The 2.2K resistor in the MKLJ would throw off your present circuit. Even if the 2.2K were disconnected, it is likely your present circuit sometimes exceeds 5 volts at the sensor. The MJLJ can't be calibrated outside of 0 to 5 volts. But connecting a sec...
- Tue May 18, 2010 3:48 am
- Forum: Operation
- Topic: Aux input (voltage to input) Megajolt v4 jr
- Replies: 14
- Views: 14320
Temp Sensor
The MJLJ has an internal 2.2K pullup resistor to internal 5V. It can be calibrated to use a standard EFI temperature sensor. Is your present sensor already in use in the car; sensors don't have an internal voltage? Adding another might be the easiest. Bruce Roe
- Sun May 16, 2010 7:08 pm
- Forum: Q&A
- Topic: Jumping timing
- Replies: 8
- Views: 7168
TIMING JUMP
It sounds to me, as though its jumping between programmed spark and (10 degree) limp mode. I doubt it is the VR, because losing sync there would put your timing all over. I'd suspect the MJLJ or its wiring; at this age, a loose or tarnished connection could do it. Cleaning or wiggling the chips that...
- Sun May 16, 2010 3:48 am
- Forum: Installation
- Topic: No spark, shielded cable?
- Replies: 4
- Views: 4239
NO SPARK
The wire gauge of the shielded cable is unimportant. You need 2 wires inside each shield, esp for the VR, and the polarity is critical. I found that communication from the PC to the MJLJ didn't really work, unless the engine was running. You can use a pretty log cable to the PC, though. Good wiring ...
- Fri May 14, 2010 3:03 pm
- Forum: Powered by Megajolt Gallery
- Topic: VW 1500 Squareback with Megajolt
- Replies: 10
- Views: 23349
VW
Very impressive work. I suppose you have some sort of fuel injection? Bruce Roe