2ndGenGuy's '81 Hatchback MegaJolt Lite JR Conversion

[stat1K]

i have internet at home, on my phone, and at work, i just do most of my surfing at work lol...

i had a question on your shielded wiring, i was pretty certain that for shielded wire to truly be shielded the shielding itself needed to be grounded?

[2ndGenGuy]

i have internet at home, on my phone, and at work, i just do most of my surfing at work lol...

i had a question on your shielded wiring, i was pretty certain that for shielded wire to truly be shielded the shielding itself needed to be grounded?

I do a bit of surfing at work as well.

Yeah, you are supposed to ground the shield to the chassis according to the wiring diagram. I'm not sure how well this is going to hold up, being that the shield is just a foil wrap. But we'll see. I didn't actually know that until I started this project. I figure that's why my shielded RCA cables for my stereo never seemed to do dick, I never grounded them!

Here's the wiring diagram that shows it:

[stat1K]

yeah, typically there are some stranded wires inside that foil rap that you can access and ground accordingly, that's what i did when i rewired the crank sensor in my distributor, i used a ground on the ecu harness (obd0-obd1 locash harness) and attached the few stranded wires to that. seems to work well.

[Civic Accord Honda]

Whats the difference in shielded wires? i know i was told to use them on my dizzy wiring when i did the mpfi swap on the civic but i just used regular wire lol

[2ndGenGuy]

Shielded wires will prevent any outside electrical interference. It's usually used on wires that carry a signal, like for distributors or ignition systems that use sensors to tell where the crank/cam are at in their rotation. Power wires can cause interference and distort the signal and cause your timing to not fire properly...

I found the stranded wire inside my shielded wire. When I pulled it out, I was like "oh duh!" So yeah then I just crimped it into a ring terminal.

But anyways, yeah some good updates today.

Here's what I pulled out of the engine bay:



And how the engine bay looks, a little tidier without it.



Ugh, I don't know why the pics turned out blurry. Sorry they look like shit, I'll get better ones when I get done.

Here's the trigger wheel done, rotated properly, mounted, and the sensor mounted as well, again, this pic sucks:



Here's the location of my new coil packs.


And the mess of wiring in the engine bay.



Soooo. I finished the Basic wiring tonight. Just wanted to start simple and hook up the minimal needed so I have less things to troubleshoot in case it didn't fire. Well good thing too, because the thing wouldn't fire. The EDIS controller is supposed to go into a "limp home" mode when there is no ECU to tell it what to do. Which fixes the timing to 10 degrees. I left the MegaJolt computer disconnected and it's still not firing. I'm getting no spark at all. The manual says to reverse the polarity of the VR sensor, but I still haven't had any luck after doing that.

The diagram show's pin 7 connected to the shield, but I haven't done that. I thought maybe the diagram was just showing the shield ground connection bypassing the pin. Maybe I'll try hooking that up and see what happens... Hopefully I can get it fired up tomorrow!

[2ndGenGuy]

Okay I've got my own update already. Looks like the max distance from the trigger wheel to the sensor is 1mm. So I'm going to have to check it, and maybe get the sensor a little closer to the wheel. I bet that's why it's not firing!

[Civic Accord Honda]

Good luck , hope it something simple and u get it fired up!

[2oodoor]

Love this thread! just a few cents...
$Reversing poles, on that I have seen various crank sensors start responding after simply unpluging them and reconnecting, sort of "depolarizing" I reckon.

$ Never energize this type system unloaded, or not having a secondary outlet at all. Simple terms, suppose you had a single cylinder motor and during diagnostics you removed the spark plug from the hi tension lead and then left the HTL somewhere it can't reach ground to arc.. then turn the motor with ign primary feed on...no no no it can fry the controller and or ignitor.

$ Make sure you have a fully charged battery and plenty of juice for cranking AND bustin off this ignition or you will be chasing ghosts. You will need a lot of fire to get this thing going the first time since youve likely turned it over a bunch with no bang bang during the process here.

[markmdz89hatch]

I hate you John.

btw... good info on that shielded wiring there. Where can I get shielded wire?

[2oodoor]

I hate you John.

btw... good info on that shielded wiring there. Where can I get shielded wire?

www.techni-tool.com

local hvac and industrial supply should have it too, like grainger, msc,etc

[2ndGenGuy]

Love this thread! just a few cents...
$Reversing poles, on that I have seen various crank sensors start responding after simply unpluging them and reconnecting, sort of "depolarizing" I reckon.

$ Never energize this type system unloaded, or not having a secondary outlet at all. Simple terms, suppose you had a single cylinder motor and during diagnostics you removed the spark plug from the hi tension lead and then left the HTL somewhere it can't reach ground to arc.. then turn the motor with ign primary feed on...no no no it can fry the controller and or ignitor.

$ Make sure you have a fully charged battery and plenty of juice for cranking AND bustin off this ignition or you will be chasing ghosts. You will need a lot of fire to get this thing going the first time since youve likely turned it over a bunch with no bang bang during the process here.

So I should always have the coils hooked to something so that it fires off? So if I remove all the spark plug wires for some sort of diagnosing and turn over the engine, I could fry the EDIS module?

Thanks for the info, I'll definitely keep it in mind!!

Oh yeah shielded wire should be purchasable at any real electronics store. I got mine at ERI here in Olympia, best store ever!!! They'll ship to you too.

http://www.eresourcing.com/

Their website fails though. But if you know what you want, you can get pretty much anything from them.

[stat1K]

ace hardware typically carries some shielded wire, but i've gotten mine at homedepot, sometimes you can only get 4 wire but i just use two of the wires and ignore the other two, or use them for something else ya know?

[cygnus x-1]

Is it running yet?


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[2ndGenGuy]

No not yet. For some reason I'm only getting 1.2 volts AC across pins 5 and 6 on the EDIS module (the VR sensor pins). I was getting 0.9 volts AC earlier, but bumped the sensor a bit closer to get the 1.2. It still won't fire though, and I'm wondering if it's not the steel mounting bracket I made for it causing some magnetic interference... I don't know if I can get the sensor any closer to the trigger wheel or not. After looking a little harder, I did notice some runout (like I figured would have happened after redrilling), but it still doesn't look like more than 1mm. I think I might just need to start from scratch on the trigger wheel mounting at this point... grr.

[cygnus x-1]

No not yet. For some reason I'm only getting 1.2 volts AC across pins 5 and 6 on the EDIS module (the VR sensor pins). I was getting 0.9 volts AC earlier, but bumped the sensor a bit closer to get the 1.2. It still won't fire though, and I'm wondering if it's not the steel mounting bracket I made for it causing some magnetic interference... I don't know if I can get the sensor any closer to the trigger wheel or not. After looking a little harder, I did notice some runout (like I figured would have happened after redrilling), but it still doesn't look like more than 1mm. I think I might just need to start from scratch on the trigger wheel mounting at this point... grr.

That voltage sounds too low. Are you measuring that with a meter or a scope? A meter probably won't give a very useful reading due to the pulsed nature of the signal that the VR sensor puts out. Also, are you measuring with the sensor connected to the module or just the sensor itself? Almost sounds like you might have a bad sensor.

The steel bracket should be fine. I used a steel bracket on mine initially and it worked without issue.

Any chance you can get some video of the pulley and sensor while you're cranking it over? As long as the VR sensor is producing a strong enough signal it should at least fire. A lot of runout would make it run ragged but it should still run.

Another possibility is that you have a bad module. They're pretty rugged but failures do happen.


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[2ndGenGuy]

That voltage sounds too low. Are you measuring that with a meter or a scope? A meter probably won't give a very useful reading due to the pulsed nature of the signal that the VR sensor puts out. Also, are you measuring with the sensor connected to the module or just the sensor itself? Almost sounds like you might have a bad sensor.

The steel bracket should be fine. I used a steel bracket on mine initially and it worked without issue.

Any chance you can get some video of the pulley and sensor while you're cranking it over? As long as the VR sensor is producing a strong enough signal it should at least fire. A lot of runout would make it run ragged but it should still run.

Another possibility is that you have a bad module. They're pretty rugged but failures do happen.


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I'm just using a cheap $3.00 Harbor Freight multimeter, measuring with the sensor connected to the module. I haven't tried it without the sensor connected yet, I wasn't sure the sensor would even generate any kind of signal at all without something sort of powering it. The Vehicle Installation Guide on the MegaJolt site says that a meter should should read 2.5v.

I might be able to borrow a scope from work, but I'm not sure the one we have will do what I need, nor do I have a clue how to use it. I'll get some video of the wheel here in a bit.

The module does seem like it might be bad. I'm thinking about hitting the yard today and picking up another one just to see...

[2ndGenGuy]

Well never mind, I'm an idiot. I was using the timing light to check for spark. Apparently it wasn't picking up. I pulled the spark plug to make sure and it fires... durrrr! So now I gotta get the car to start, which means I need to trick the fuel pump into turning on when cranking.

[cygnus x-1]

Well never mind, I'm an idiot. I was using the timing light to check for spark. Apparently it wasn't picking up. I pulled the spark plug to make sure and it fires... durrrr! So now I gotta get the car to start, which means I need to trick the fuel pump into turning on when cranking.

Ahh, that's good there's a spark! Some timing lights don't work right with wasted spark setups. The older "fixed" type lights tend to work better than the newer "dial back" ones that have the variable delay.

For the fuel pump relay you need to use the diode circuit described on the Megajolt installation page:

http://www.autosportlabs.net/MJLJ_V4...allation_guide

There is also one addition to that circuit that you will probably need. You need to connect a 10k (anywhere from 2k to 50k would probably work) resistor from the tach/FPR line to ground. We found that on the 2g 'ludes the diodes by themselves don't reliably trigger the FPR. It might work ok for just the tach but it tends to be sporadic.


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[2ndGenGuy]

Is it better to use that diode circuit as opposed to using the RPM out on the MJLJ? Also, I just read that pin 11 on the EDIS is a Clean / Clear Tach Out. This one won't work? Or is it just more reliable to use the negative off the coils?

[Hazwan]

OMG I cant wait to see it done!!

[cygnus x-1]

Is it better to use that diode circuit as opposed to using the RPM out on the MJLJ? Also, I just read that pin 11 on the EDIS is a Clean / Clear Tach Out. This one won't work? Or is it just more reliable to use the negative off the coils?

You can try those but they probably won't work. I seem to remember trying the EDIS tach out and it didn't do anything.

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[2ndGenGuy]

Well the tach out on the EDIS does run my tachometer just fine. I used a little starting fluid and the car fired right up!! But it won't fire the fuel pump. I'm going to just bypass the relay for now, since I can't get any diodes tonight. Do you have a picture by chance of how you set up those diodes? Did you put them on a little board in a box or just heat shrink around the diode and put them inline with the wire?

[2ndGenGuy]

Well, I bypassed the relay and put in a switch for now, man it's awesome! It's so weird to see it running without the distributor on there! It's just in limp home mode for now. Runs a little rough because it's cold, but seems to clear up a bit after warming up. Probably going to add in the GM thermosensor eventually. Thanks for all the help and input! Here's a video of the engine running!

http://www.youtube.com/watch?v=wQdK--uMrY4

[2ndGenGuy]

w00t! Got the MegaJolt stuff working too! The default ignition map works pretty good for piddling around in the garage. I played with the configuration app for a while just to see how it works. Pretty sweet stuff. Once the car warmed up, it idled SO smooth! The engine was so quiet too. I had no idea how loud that distributor was. Just goes to show what POSes those AutoZone rebuilds really were. Here's a video of the MJLJ in action!

http://www.youtube.com/watch?v=o1E8jsiFdFc

[Catalyst]

Wow! Awesome! I am impressed!