Coil questions

General Megajolt Questions and Answers

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pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Coil questions

Post by pope101 »

Hey guys!

Another electronically inept person trying to setup EDIS on his car.

As i live in Australia i have had a tough time sourcing a coilpack to do the job.

I have purchase a Subaru coil pack that suits some 95-00 models and has the standard 3 pin setup. However when i tried to run this coil ONE side got very hot to touch after a couple of minutes. I also got no spark.

I specifically told the guy i didn't want a coilpack with inbuilt igniter, but i think it may do.

So my questions are as follows:

IS there a way to test if a coilpack has an inbuilt ignitor?
Both the coils i have measure nothing on the secondary resistance, i am connecting the multimeter between the center pin and one of the posts, is this correct?
If my coils were both wrong does anyone know the model number of a coil that i could get ordered (there are no wreckers anywhere)?
Lastly if i had say a very poorly created trigger wheel, 1-2mm differences in teeth width, would this generate no spark or just a unreliable one?

alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

Post by alexander »

greetings...

*no, that is not the correct way to measure secondary coil resistance. unlike a normal coil, the secondary has no common terminal with the 12v supply. you have to measure secondary resistance between the two HT terminals. i have genuine Ford coil packs and the resistance across the secondary is about 13k ohms. ie 13,000 ohms.

*the primary resistance ie between the center pin and either of the others, is about 0.6ohm. across the two outer pins it is, not surprisingly, 1.2ohm.

*i dont know for sure how to test if any particular coil has in inbuilt ignitor, but start my measuring the resistance as above, and let us know what you get. do you have a digital meter.

*re ford coil... i am also in australia, but bought mine used from the US on ebay. type EDIS 4 as a search. there are a few items there now. admittedly, as you have all the stuff, that would be a little expensive. other options are to get a coil pack from a recent EDIS equipped ford v8; they simply have two of the coil packs. or check out ford mondeo coil packs. i believe they use EDIS too. someone else from australia put up a post here the other day regarding the EDIS unit he had.

or, www.trigger-wheels.com in the UK sells new and used coils, and everything else. only problem there is that post from the UK is very expensive. and of coure the collapsing A$!

*irregular teeth: as long as edis could distinguish each tooth, i think the only effect would be slightly incorrect timing. EDIS counts teeth, and fires when the right number have passed by. how much out could it be? a couple of degrees? obviously that would be non optimal, but for your and my purposes, i reckon it would make almost no difference. that level of accuracy is beyond most peoples ability to determine what is optimal anyway. i assume you are asking regarding getting no spark? well, maybe yes, maybe no! can you put up a photo of your trigger wheel? there are many possibilities. perhaps the sensor isnt close enough, for instance. perhaps the sensor really cant distinguish all the teeth. perhaps it is the coils at fault etc.

lastly, may i ask where you are?

regards
alexander
surry hills, sydney.

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

Whoa thanks for the reply.

Coil measures 10k then rises to inf in ~2 seconds so i think it should be ok. I get about 1.0 on the primary.

I did have a mondeo coil pack originally but they said it had an internal ignitor. The wreckers around here only have cars older than 1980's useless.

Trigger wheel could be out as much as 3 degrees but average would be 1 degree. Just scrapped it up this arvo to test it.

Will take a photo of the wheel maybe tomorrow if i get time. If you have ever seen a 3tc just imagine the crank pulley with holes drilled in the front of it.

I'm in Hobart Tasmania BTW. It's good to see a fellow Aussie as most guys i know just tell me to get an Adaptronic or some shit.

Cheers Josh.

TwoSheds
Posts: 64
Joined: Sat Jan 12, 2008 9:44 am
Location: UK, near Leeds

Post by TwoSheds »

Forgive my ignorance - I am from the 'old country' so it may be a terminological thing - but what is an 'internal igniter' please?

Rog

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

I'm not entirely sure if this is accurate but from my understanding it would be like having The part of the EDIS system that drives the coils inside the coil pack. Basically internal igniter coils take a different type of signal input.

alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

Post by alexander »

pope101 wrote:
Coil measures 10k then rises to inf in ~2 seconds so i think it should be ok.
.
josh, i am concerned about this bit. the meter should give a steady resistance reading,and it should not change at all. not sure what it means exactly, but it is certainly not simply reading the resistane of a simple coil of wire if it does what you describe.

interesting about the mondeo. the UK ones definitely are donors for EDIS parts; i would be odd if the local ones were not, but not out of the question. could warrant some investigation.

regards
alexander.

alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

Post by alexander »

hi, obviously i am bored at work so have been doing some further checking.
i found this site - good site too -
http://wiki.datsun1200.com/index.php?ti ... oldid=3522

which says:
"Australia
These work with EDIS controller:

Any Ford 36-1 trigger wheel and VR sensor, e.g. Falcon
1997 V8-fitted LTD with EDIS
Zetec engine VR sensor (points at flywheel)
These reportedly with with an EDIS controller. Use at your own risk:

GM DIS coil pack
Chrysler coil pack
Bosch coil pack
Measure the resistance and check to make sure it compabilte."

seems like the genuine part is an accel 140018 coil.

[i removed the ebay US link to summit racing due to their postage rate of US$60 + US$24 handling!]

i think, however, you should just go to a ford parts counter and ask there. i am about to fit a second mj, this time to my v8 jeep. i bought the coil pack from someone in australia, and it came from an XR8 falcon. so ford do use them here, and therefore must sell them here. you just have to ask for the right part. you might find one at a wrecker if you ask in those terms?

lastly, there is a thread somewhere here from someone in australia who has used a twin coil pack from some other car, which had the advantage of using regular spark leads.

alexander.
Last edited by alexander on Thu Oct 16, 2008 11:20 pm, edited 1 time in total.

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

Thanks Alexander,

Just skimmed through your posts as i have to get to work, but i re measured my coil. I'm getting 19.6k steady on both sides now.

I also found out that i'm useless with multimeters. :P

alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

Post by alexander »

pope101 wrote: I also found out that i'm useless with multimeters. :P
...but getting better!....

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

Ha ha slightly.

Gonna go have another crack at it, but in the meantime here is my trigger wheel.
Attachments
PA186670.JPG
PA186670.JPG (166.64 KiB) Viewed 9364 times

alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

Post by alexander »

firstly, the trigger wheel. looks like it should work. another person on the forum recently posted a picture of similarly drilled crank pulley (holes drilled in from the periphery), with a perfect waveform on a 'scope. so your wheel certainly should work.

as opined earlier, i reckon, applying all the expertise which can be applied by an amateur know-all looking a photo on a discussion forum, that there would likely be <1deg variation between any of the holes. so it cant make any bucket on your map out by more than 1deg. given that timing can vary from, say, something up towards 40deg btdc, to tdc, i dont think that is ever going to make any discernible difference to performance. if you were trying to maximise power in an envelope-pushing race engine, well, maybe. but for thou and i, that's good enough. as ever, IMHO.

secondly, getting back to the original problem: no spark and a hot half of the coil. obviously the car wasnt running, so the coil wasnt heating up from actually creating spark. to me, that says the coil is not correctly wired. the heat is there because there is a continuous current flow through half the coil. if that is so, it isnt going to be creating any spark! if one half of the coil is getting continuous current, then there will likely be something up with the wiring for the other half. like, maybe no current at all?

so i think that is Step One: make sure you have determined which pin on the coil is which, and check you wiring loom.

regarding the pins: if the coil is in fact ok to use, there are 3 pins. one of them is in the middle of the two primaries, and should have be connected to a constant 12v supply. each of the other two goes separately to the A and B coil connetion on the EDIS. you will know which pin is which, like this... measure the resistance between all 3 pairs of pins. you should have (about) 1.2ohm between one pair, and 0.6ohm between each of the othe pairs. the A and B connectors are the ones between which there is 1.2ohm resistance. the +ve supply is the 'other' one.

once that is done, make sure that your +ve wire really is a continuous 12v supply, and that the A and B wires go to the right pins on the EDIS connector.

that is you mission; report back at your leisure :)
alexander.

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

It works YAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAY

I don't fail at all things electrical.

I did another test run the same as before except i used a spare head with some spark plugs in it.

Coil doesn't get hot anymore :) and i'm getting good bright sparks.

Thanks Alexander, it's good to get a second opinion on the trigger wheel. I've got a spare pulley that i will take and get machined properly just in case but this one will do for now.

Halfway making a bracket so I will get back to it and let you know how I go.

alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

Post by alexander »

great news! one thing i guess everyone here can share is that moment when the thing actually works. you know, relief and smugness all rolled into one.

do you mean it works on a test bench of some sort, or do you mean it works in the car using the trigger wheel you photographed?
either way it is probably premature to have another pulley machined, is it not?

anyhow, good going...

alexander.

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

When i posted it was just on the test bench.

But I've got it running the car now :). Bloody good feeling.

Had a quick go at hooking up the megajolt but i stuffed a few things up and ran out of time.

I also broke one side of the sensor so had to modify the bracket quite a bit.

Timing is absolutely rock solid on 10 btd. Will be interesting to see if the rpm reading is stable.

The whole setup is pretty hacked together ATM and i would like to redo it properly but i will see how we go.

pope101
Posts: 22
Joined: Thu Oct 16, 2008 7:51 am

Post by pope101 »

Jolt is in and working after many wiring mistakes.

One last thing to figure out is why the hard rev limiter seems to shut the coil off for a second or two before kicking back in.

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