Mega Jolt Light Junior thread for a /6, Because folks have asked Options

[Dr Evil]

According to this diagram which matches my pully and to page 85 of the 911 Haynes manual. (IMG:style_emoticons/default/confused24.gif)

[lapuwali]

Hm. I think that's assuming a vacuum distributor is involved that supplies enough advance at even idle to set the timing to actually be 7-10BTDC. If you unhook the vac advance, a timing light will show 5ATDC (and it will run like crap). My Haynes manual is 25 miles away from me right now. If the manual says it should be 5ATDC with the vacuum hooked up, I'd suspect yet another Haynes error.

[Dr Evil]

Definetly not the first error I have found. It did say "with vacuum" hooked up. I'll goof with advancing it to 5 BTDC and see what happens.

[Dr Evil]

Damn Haynes (IMG:style_emoticons/default/dry.gif)

So I re read the paragraph and ignored the pictures....they do not agree, or I didnt get it, but the written part says 5 BTDC. AHHHH!

So the pully is MARKED for 5 ATDC, but the timing is supposd to be at 5 BTDC, which is approximately = to 5mm of the crank pully....and is not friggen MARKED!

Sooo, I am gonna reprogram my unit to run at 5 BTDC at idle.

[smdubovsky]

Good Dr,
W/ carbs you typically run 10*BTDC @ idle. The near zero/negative thing is for emissions. F-that;) My twin plug starts @ 8*BTDC I think.

When your checking the crank pulley alignment, LOCK THE TIMING. If the MS doesnt have a way to do it, then program all cells to 10 (or zero, or some other convenient #) and start the motor. You'll never get it checked out if the timing is jumping up and down due to vacuum fluctuations or something like that.

Do one thing at a time:

1) The motor will run/idle smoothly @ 10deg (well, it might run like shit up top but likely will just meake no power). Make sure the timing stays constant though the rev range (to verify the trigger signal isn't breaking up or have interference)

2) Set some angle up to 1000rpm, go to full advance @ 3500rpm, and stay constant above that. Leave the vac advance out of it for now. Verify you can rev the motor and have the timing follow along. If the timing light is rock solid all the way up to redline your sensors signal is good. Now would even be a good time to go for a drive.

3) Add the vac advance in. Its an emissions only thing. It can wait until you get everythign else running fine.

Baby steps;) The ignition is the trickiest part of EFI.

BTW, the MS should interpolate between values - you DONT want to add in the rev-limit retard from 5000rpm to 6500rpm. The 6500 should be the same as all others, and the 7000 should drop like a rock towards zero. That puts the soft 'rev limit' somewhere between 6500 and 7000. James is right, it will fall flat on its face w/o the advance (but it makes the exhaust hot so dont drive around on the limiter;)

BTW2, you can stabilize idle/add anti-stall by adding advance. Say, you want to idle @ 900rpm and want to use 5*BTDC, Put that in a 900rpm bin. Add a 700rpm bin w/ 10-12deg. The advance will push the rpm back up to 900.

You want to keep the advance flat from 900-1000. If you add any advance at idle -> it increases power -> raises rpm -> more advance -> more power -> more rpm. It makes the idle either rev happy or hunt. You want a rpm range AND pressure range at idle w/ the same advance.

SMD

[Dr Evil]

Yesterday I had it set up for running 0 advance programmed at 5 ATDC so as to keep with what I was understanding in the curve. After getting advice here and re re re reading the manual I realized that I should have been at 5 BTDC (probably as it was not definitive) or more according to all of you here. I have now reprogrammed my MJLJ box to run at 5 BTDC and to climb quickly to full advance by 3500 RPM. The tables that I have been posting are not as accurate as I thought. In the Mega Jolt there area only 10 x 10 bins so I had to estimate/dump some values. For the rev limiter I put a 6800 bin at the top of the curve that runs at 15 BTDC to limit it. I may need to add a 6000 bin to make sure the curve does not peter out until after that value.

Things that I have verified:
-MJLJ box and EDIS is working correctly. I could adjust the idle timing to what I wanted which verifies that the box is working as it would stay at 10 BTDC if it were not.
-VR sensor and coils are functioning properly. Getting good solid spark at the correct times that I program in. With the new advance info it shold run a lot better.

I have yet to add in the vacuum as I need to get a hose to do so. Thus, this has not yet been a factor in operation, yet.

Thanks for the further clarification.

[DBCooper]

Baby steps;) The ignition is the trickiest part of EFI.

BTW, the MS should interpolate between values - you DONT want to add in the rev-limit retard from 5000rpm to 6500rpm. The 6500 should be the same as all others, and the 7000 should drop like a rock towards zero. That puts the soft 'rev limit' somewhere between 6500 and 7000. James is right, it will fall flat on its face w/o the advance (but it makes the exhaust hot so dont drive around on the limiter;)

BTW2, you can stabilize idle/add anti-stall by adding advance. Say, you want to idle @ 900rpm and want to use 5*BTDC, Put that in a 900rpm bin. Add a 700rpm bin w/ 10-12deg. The advance will push the rpm back up to 900.

You want to keep the advance flat from 900-1000. If you add any advance at idle -> it increases power -> raises rpm -> more advance -> more power -> more rpm. It makes the idle either rev happy or hunt. You want a rpm range AND pressure range at idle w/ the same advance.

SMD

Verrry Clever! Boy, you EFI guys are really really smart. Looks like I'm doomed to a life with carbs...

[lapuwali]

The ECU in question isn't MS, it's MegaJoltLightJr., a completely different EDIS-only controller put together by Brent Picasso. Different board, different processor, totally different code. The fuel system the good Dr. is using is CIS. I believe MS is in his long-term plans.

It's an open question as to whether or not MJLJ interpolates between bins. The code is available online (or used to be), so I'll probably take a glance at it to see.

Post your complete map when you've got the engine up on its feet. I'll be doing EDIS (with carbs!) on my 2.7 within a couple of months.

[lapuwali]

OK, it does interpolate. The last time I looked at the source, it didn't. So, the rev-limiter portion of the map should look more or less as described earlier by SMD. One bin past redline should have very low advance, and redline should have it's own bin with max advance. Advance will taper off sharply past redline, which is what you want.

[lapuwali]

Actually, Paul, I was answering SMD.

I really am using EDIS with carbs, at least initially. Carbs are substantially easier to get running than DIY EFI, esp. considering my car already has carbs, so the fuel system is all set up for carbs.

[smdubovsky]

Dr E,
Dump as much timing as possible for a rev limiter. I'd set it all the way back to the base timing. Zero or even -10 works well. You just want to light the fuel off else you'll get flames out the tailpipes or backfires if you pull spark completely.

James,
I knew it was a MJLJ - but having never looked into it, I've always assumed it was based on the MS. Interesting to know that its completely different.

FWIW, Im waiting for the microsquirt to come out as Im tempted to EFI the /6. I've tried to put all my cars on the Atkinson diet - no carbs;) In the back of my head, Im thinking a 3.6 swap is cheaper in the long run though...

SMD

[DBCooper]

Actually, Paul, I was answering SMD.

I really am using EDIS with carbs, at least initially. Carbs are substantially easier to get running than DIY EFI, esp. considering my car already has carbs, so the fuel system is all set up for carbs.

No problem, I'm in exactly the same boat. I actually have a yet to be assembled MJLJr that's going onto a Zetec in a Lotus Seven replica, so I can use the EDIS that's on the engine but run DCOE's. No distributor on the Zetec, so no choice. Carbs in the beginning for authenticity, because I have them, and because I don't want to be juggling too much stuff at once, but the MS will come later.

[Dr Evil]

I have about had it with this crap (IMG:style_emoticons/default/dry.gif) School starts in 2 days and I will then have to store the car until maybe 7 years as I am not gonna have time to fool with this crap.....

Anyway, today was (un)eventful.

I readjusted the timing wheel so that 0 would be 0 and eventually uploaded the chart at the bottom. I put 700 RPM in as advised to help with idling.

It was odd, I held the timing light while cranking and noticed that the timing was at 0 until such time as it would catch for a quit push and the timing would adjust (IMG:style_emoticons/default/blink.gif)

Anyway, this promoted the use of the 700 bin.

I got it to run horibly for a second and have not had it running since.

I believe my mixture is off and willneed to check to make sure I am getting a good spark. So far I am only seeing the timing light light up as verification, but it seems to be responding correctly so I am not feelign it is a timing malfunciton so much as the table may not work (?).

I did all of this with the vacuum removed and plugged.

I dont know where to go now and am starting to get realy fed up withthis damn thing. I would rather have a 1.7 /4 right now than my non performing hunk (IMG:style_emoticons/default/mad.gif)

[plas76targa]

Mike, Hang in there. You'll get it worked out. Use this as your outlet for school, when you need a break from studying take an hour or so on this. Sort of a "change of scenery" for the brain.

[lapuwali]

OK, try this. Disconnect the SAW wire. EDIS defaults to 10BTDC timing if it gets no signal from the ECU as a "limp home" mode. The engine will start and run with the timing fixed at 10BTDC. It won't rev well (you'd be limited to perhaps 2000rpm), but you should be able to drive it slowly this way. If you can't get it running this way, then there's some other problem you're missing, which obviously has nothing to do with the table.

[lapuwali]

Another thing to check. Make sure the VR sensor wires aren't reversed.

[DNHunt]

Another thing to check. Make sure the VR sensor wires aren't reversed.

Good one James. Been there done that.

[Dr Evil]

Luckily I left the jumper plug in my harness so I can just pull it and cause it to go to default. I can try this. As for the VR wires, I matched blue-blue, and grey-grey. Pretty sure its not that, but I realy can not be sure of anything as it is not running at all.

An odd thing was that I had to switch where I thought coil 2 and 3 were ont he pack so that now it goes coil 1 - 3 - 2. Before this it would try to stop my engine in mid stroke....not nice.