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Index > Engine/Drivetrain > Thread: electrical issue, spark arcing from trailing ignition coil???
Thread: electrical issue, spark arcing from trailing ignition coil??? [' This thread is 2 pages long: (1) 2 ']
rotarypwrd


Revvin Up
Posts: 55
posted October 16, 2003 07:31 PM

electrical issue, spark arcing from trailing ignition coil???

vehicle: 77 REPU

mission: stop the REPU from spark arcing from the trailing coil.

have had REPU converted to electronic ignition(84 rx7 gsl) for about 8 months now with no problems until now.

for some odd reason, recently, there is a spark arcing from the trailing coil ( where sparkplug wire boot connects to coil) to one of its own connectors below it ( the ones that are on either side on top of the coil).

sparkplug wires are new ngk's from a 1st gen rx7. I've thought about replacing just the spark plug wire, but I don't want to guess what the problem is. Basically, don't want to put a band aid on it, I want it cured and I want to know what causes it. Gas mileage is also slightly worse, power seems to be decreased. Kind of scary knowing there is a spark under the hood while driving. Any helpful, suggesstions, troubleshooting is greatly appreciated.

for a picture of the location I am taking about look @ this link. It's in this subject forum under " converting to electronic ignition" pg.4

http://www.mazdarepu.com/board/viewthread.php3?FID=2&TID=187

thanx, rotarypwrd

       
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Klaus43


Rotorhead
Posts: 1259
posted October 17, 2003 11:56 AM

Try this:

Swap out the wires from the coil to the dizzy, leading and trailing, just to see if it's the wire... easy, quick way to tell... that is, if the problem switches along with the wire. If it doesn't, it must not be the wire... Also good to get an ohmmeter to check for resistance... lotsa wires suck!
But wait, there's more: Isn't the '84 ignition the year of 'remote mount' ignitors, prone to cross-triggering??? If this is the ignition you have, take it out and throw it away, replace with the dizzy-mounted 1st-gen ignitor setup, and your trouble should be cured... if it wasn't the wires, coils, or some other electrical demon.
Best of luck, Tomas!

       
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Klaus43


Rotorhead
Posts: 1259
posted October 18, 2003 10:16 AM

Or...:

Could be a bad coil, or perhaps a dying igniter? I dunno, I'm not an electrical expert... Still, I'd eliminate the wires first. Best, K.

       
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Jeff20B


Moderator
Posts: 661
posted October 18, 2003 08:33 PM

Swap wires first. It could simply be a loose fitting boot. Then replace the coil if necessary. I've seen a dead FB coil out of a '77 REPU that had an arced-through high tension tower. It does happen.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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brad


Rotorhead
Posts: 1672
posted October 19, 2003 10:46 AM

I've seen coils that have burned thru the top of the coil where the spark plug boot slips on. Check that.

If the coils haven't been replaced with new ones in 20 years then it's time for a new set. Check yours with an ohmmeter and compare to factory shop manual specs.

MSD Blaster 2's are what I use in my racecar and REPU and are a great spark for the buck.

Band-aid fix is to put di-electric grease on the spark plug boot.

Good luck Tomas, glad to hear the REPU I towed and ressurected is being used!

Brad
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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rotarypwrd


Revvin Up
Posts: 55
posted October 21, 2003 01:53 PM

many thanks to klaus, jeff20b, and brad.

get this, took the "swap the wire" advice and it seemed to cure the problem, still don't understand why it was doing it in the 1st place.

I basically interchanged trailing and leading wires to the coils ( original trailing wire is now leading and viceversa), if it was a faulty wire than it would still be arcing now on the leading coil, but it's not, and the trailing coil isn't either. Seems to be runing fine now after the switch, and no arcing on either. Ran it around the block to see if it would comeback, still no arcing. Weird, huh? any thoughts, I have no complaints, it was just odd how the switch solved it.

Brad, or anyone else, know of a good place to get those MSD blaster2 coils for a good price( model/no. also)? Also, Brad, Tina was wondering if we could get that OEM REPU pamphlet we let you borrow to scan back? Thanx again for all your past and present help w/ the greenmachine.

rotarypwrd

       
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brad


Rotorhead
Posts: 1672
posted October 21, 2003 05:08 PM

MSD-8200

http://store.summitracing.com/default.asp?target=search.asp&type=bykeyword&searchtype=both&part=msd+blaster+2

I'll scan the pamphlet and can either drop it off or you can pick it up @ my work in cerritos or LaPalma. Just email me.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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Klaus43


Rotorhead
Posts: 1259
posted October 21, 2003 05:44 PM

Perhaps...

...that bad wire is a case of internal breakage/partial or intermittent contact/lessened voltage... and now your trailing is firing with a lesser spark? This might never be apparent until you pull the plugs after a number of miles... Best to replace! (Do as I say, not as I do... I run all manner of crap until it just won't work anymore...)

       
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Jeff20B


Moderator
Posts: 661
posted October 22, 2003 12:56 AM

quote:
Seems to be runing fine now after the switch, and no arcing on either. Ran it around the block to see if it would comeback, still no arcing. Weird, huh? any thoughts, I have no complaints, it was just odd how the switch solved it.
I've done things like that before. Abstract thinking plays a huge role... for me at least.

I'm with Klaus. Just buy new wires whenever. That's what I do. :)
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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Klaus43


Rotorhead
Posts: 1259
posted October 22, 2003 07:46 PM

It's been asked:

"What are the best wires for rotaries?"... I would add, "What's the biggest bang for the buck out there these days?" As long as it's REAL wires... none of that carbon-string crap! I keep seeing some sets for rx-7 on ebaymotors... are these worth a damn? I'm still running an old set of Taylors, look custom-made by a P.O. ...
Thoughts, opinions, advice anyone?

       
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rotormunky


Redlining
Orlando, Florida
Posts: 424
posted October 23, 2003 02:28 AM

quote:

I'm still running an old set of Taylors, look custom-made by a P.O. ...
Thoughts, opinions, advice anyone?


Overkill it may be, but I run a set of Magnecore 10mm on my '91 cabrio. THe boots are very nice and well made and the fibreglass sleeves are nice too. THe wire set that the PO of my cabrio had on there had actually worn through to the shielding from rubbing on a bracket in the engine bay. They were $30 cheapies.

Overall I'd say the Magnecores were worth the $70 I think I paid for them. They're still in great shape and test well on the ol' multimeter and its been two years.


____________
-Martin
Orlando, Florida

http://www.themonkeyhouse.org/REPU

'77 REPU (Some assembly required :)
'91 Cabrio (Battered and bruised, but she's still my baby.)

        Click here to visit rotormunky's homepage. 
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rotarypwrd


Revvin Up
Posts: 55
posted November 29, 2003 02:54 PM

Update on progress...

Many thanx to all of you who chimed and lent some helpful advice.

Here is where we currently stand.
1) Just installed complete header and exhaust system for the REPU. 2 pipes all the way through 2 presilencers that collects into the primaflow muffler. Racing Beat's complete road race setup.

2) After test driving, noticed all dash warning lights come on now. Coolant, Engine/Check, Oil, Exhaust Overheat(this one has always been on). Thought it was alternator showing signs of age/ failure. Had it tested while on the vehicle(running) and confirmed that the truck was running on the battery. Swapped out alternator, alternator belt, (while I was at it) cap n rotor, magnecore wires.

3) Problem (warning lights still on) and new problem: rough idle(sounds like its missing).

any suggestions?
rotarypwrd, tomas Is there a rotary medic in the house?

       
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brad


Rotorhead
Posts: 1672
posted November 29, 2003 08:15 PM

The Magenacore 10mm wires are simply a high quality product start to finish. I use them on my 12a J-Bridge racecar and they're great. Worth the money.

As for the warning lights, get a shop manual and track it down. Might be a bad ground or electronic box which is under dash drivers side. Stock battery cables?

What's the voltage @ idle and @ 4000+rpms? Should be 12.6+ and 13.8+ respectively

I bet the rough idle is fuel mixture. When adding a hi po exhaust you need to richen the mixture. Call Mazdatrix and see if they'll give reccomendation but I bet the primaries would get richened by 5-10 and secondaries 5 or less.

Couldn't hurt to pull the plugs and clean them with brake fluid and a tooth brush. Dry. Install and readjust idle mixture.

The Racing Beat PrimaFlow Muffler will last a long while but is the biggest restriction in the exhaust system. Replacing it with a Magnaflow 2.5" straight thru muffler with Flowmaster collector will noticeably add more HP and it'll rev much better. Been there, done that! Their 33" long muffler (27" long can) fits perfectly behind the axel.

quote:
Many thanx to all of you who chimed and lent some helpful advice.

Here is where we currently stand.
1) Just installed complete header and exhaust system for the REPU. 2 pipes all the way through 2 presilencers that collects into the primaflow muffler. Racing Beat's complete road race setup.

2) After test driving, noticed all dash warning lights come on now. Coolant, Engine/Check, Oil, Exhaust Overheat(this one has always been on). Thought it was alternator showing signs of age/ failure. Had it tested while on the vehicle(running) and confirmed that the truck was running on the battery. Swapped out alternator, alternator belt, (while I was at it) cap n rotor, magnecore wires.

3) Problem (warning lights still on) and new problem: rough idle(sounds like its missing).

any suggestions?
rotarypwrd, tomas Is there a rotary medic in the house?

____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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Klaus43


Rotorhead
Posts: 1259
posted November 29, 2003 11:00 PM
Edited By: klaus42 on 29 Nov 2003 23:02

Did the new alternator

need to be polarized prior to install? Regardless, triple-check over all connections... What're the odds there's a partial break in an important wire, internal to the insulation? They are, after all, 30 years young... Bad ground would be the simplest thing... How far gone was your battery? Did you take it out, clean it well, check fluid level, and stick it on a trickle charger overnight?
What about a relay more-or-less coincidentally going kaput? Parts do wear out...
I hate electrical problems! What a pain.
(Hope you went with the Gates belt--they last the best...)
Brake fluid for plug cleaning? Well, I never... Learn som'thin' new every day...
Best of success, Tomas!
(My bet is the rough idle is due to weak spark, and your plugs getting fouled...)

       
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wankel_dreams


Redlining
Posts: 293
posted November 29, 2003 11:00 PM

aside from the warning lights, are the guages working? could it be that that the ECU/warning system doesn't know that the engine is running and has all the lamps on like before you start the engine?
____________
74 wankel panther
77 REPU
79 rx7
89 Vert

        Click here to visit wankel_dreams's homepage. 
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Klaus43


Rotorhead
Posts: 1259
posted November 29, 2003 11:04 PM
Edited By: klaus42 on 29 Nov 2003 23:04

ECU?

I thought Tomas was running the oldschool carb'd motor...?
Perhaps the demon's in the ignition switch...?

       
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brad


Rotorhead
Posts: 1672
posted November 30, 2003 09:08 AM

brake cleaner to clean the plugs

I stand corrected. Brakleen in the dark green can with black cap. Spray plugs with it, scrub with tooth brush, repeat. Brake cleaner does a wonderful job at cleaning dirt, carbon, oil, etc... and leaves no residue.


For real dirty plugs I use driveway cleaner!

Back to Tomas, is the voltage regulator working properly?
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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Klaus43


Rotorhead
Posts: 1259
posted November 30, 2003 08:35 PM

That would be the first thing

to go if polarization was an issue... I think.
I've been using B-12 chemtool and a little wire brush on my plugs...

       
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Jeff20B


Moderator
Posts: 661
posted November 30, 2003 10:33 PM

I've had great results from soaking plugs in gas. Then a wire wheel can do its job without an oiley residue gumming things up.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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rotarypwrd


Revvin Up
Posts: 55
posted December 01, 2003 12:57 PM

could it be a bad regulator?

still using old original external regulator for alternator?

also noticed that idle needle reads irratic, while the engine itself doesn't rev up n down, the actual needle reading bumps up n down.

yes I'm still oem carbed for now.

       
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