I've been having problems with my '86 RX7.
About 2 weeks ago, while I was driving, it started acting funny. I could tell right away that it was flooding. I managed to get home but just barely. The exaust smelled different and the cat got very hot. Engine stalled as soon as I let go of the throttle. Didn't start after that and flooded right away.
I swapped 3 more ECU's that I have for back up. Same simptoms.
Plugged in a spare CAS and spun by hand. The trailing coils fire strong.
Took the injector to be cleaned and checked. They reported no problems but were cleaned well.
I then checked the leading coil for spark. No Spark at the plugs. Unplug both wires from the coil and there's spark between both towers. If i stick a piece of bare copper wire in a tower and point it close to the coils base, there's spark.

Here's the twist. As soon as I plug in a plug cable. NO SPARK!!! I have MSD super conductor wires and they're fine. All four cables work in the trailing coils. The measured resistance in them goes from 130 to 165 ohms.

The CAS is not the problem. I have a spare coil with ignitor that was working before I put it in storage. Both coils do the exact same.

I noticed that with bare towers in the coil, when spinning the spare CAS by hand, the spark only goes from one tower to the other. If you put a bare metal conductor with close to 0 ohms, you can make the spark jump to something else. But if the conductor has higher resistance. No spark.

Also, with bare towers, 6 out of 10 sparks between them are strong, and the rest are tiny little sparks, only visible in complete darkness and barely audible.

I'm lost as to what this may be.

I thought the coil would be bad (both measure at 0.9 Ohms). I'm unsure about the ECU's or something else.

Any ideas?

 

I'm sure somebody has a clue to what's going on here.
I need to get this car back on the road ASAP

 

That leading coil MUST be grounded very well. (Making good contact with the engine bay.) - I actually run a ground wire from the negative terminal to the base of the leading coil.

 

I have a wire between one of the coil's mounting studs and the negative terminal on the battery.
Any other ideas?

 

FYI. Just got the car to start. Runs rough but is on. The problem seems to be the spark plug wires that are arcing really bad.
I bought these MSD about 3 years ago an have no more than 15K miles on them. I thought MSD made better quality products. These are **** IMHO, because they just arc from the entire length of the wire. Terrible.
The engine is almost flooding because the spark is crap at the plug. All energy is lost along the way.

Any suggestions on the best wires for street use available?

 

I spoke today with an MSD tech about my problem. He offered no solution and had no idea of what could have caused the problem. He did mention though, that the measured resistance of my wires is higher than their specs and that it indicates that the wires are shot.
He said that the expected life of these wires is short because they are racing wires.

Needless to say I'm very disapointed and will most likely not buy these wires again.

 

just get the NGK... not like theres going to be a power loss using them...

 

+1

stick with OEM NGK wires, have had no issue pushing 350+ WHP out of them without breakup. they will outlast almost all of these name brand "performance" wire sets.

 

Has anyone used the Racing Beat ULTRA wires?

 

why?

why do people put so much stock in the plug wires?

there is no noticable gain from spending that extra money in almost all cases unless you absolutely need the maximum spark energy you can get, in almost all cases you do not. in almost all cases you wind up with an unreliable set of wires.

if you insist on aftermarket, get a set of tailor wires for a SBC V8, you can put together about 3 sets for the same price. then you get some nice brightly colored plug wires.

 

+1 .. a scenario played out time and time again..

owner: but i paid $150 for these wires .. they are good !


8 hrs later..

me : you need new wires.. i need a life back now i proved it wasnt anything else BUT these frigging wires ..////



if i charged $110 an hour like other rotor specialists ,, would you argue the point ?


buy $7 efi bosch 8mm items ,,they work fine with HEI.. when they are dead,, they are dead,, and it doesnt hurt at $7 a piece to just swap these FIRST

 

a set of NGKs out here is a whopping $25/set and OEM quality.

 

I have nothing bad to say about the stock wires.
The thing is that, undeniably, within the realm of a relatively stock engine, the stronger the spark, the better.
The OEM wires are long on reliabilty but short on performance. We all know that all cars can be improved on by using aftermarket parts.
The trick is to buy the good aftermarket parts instead of the cheap or crummy ones.

Even a brand name can sometimes be synonymus with not so good stuff, my problem being an example.

This is my second bad experience with an MSD product. The first was a hi performance coil that went bu-bu on a Chevy SB V8 that I had. It quit (arcing from the bottom of the plastic body) in less than a year of use.

If you could chose two wires to conduct energy, wouldn't you pick the one that does so better?

I don't mind spending some $$$ if the part is worth it.

 

yes, well i hear people say the same thing about stock ignitors and coils, yet i have pushed over 500whp from STOCK coils/ignitors(magnacor wires, but they're junk and fall apart each plug change). how much spark energy do you think you need? FC ignition including the rather thin plug wires still perform VERY well.

after a point you're just burning money for nothing.

anyways, i'll end trying to convince you at that.

 

Prove it!

 

If you want to go aftermarket then i would recommend getting the Re Amemiya leads since Mazdaspeed no longer make them for the FC. Its the highest quality your going to get but its not cheap.

I agree with RotaryEvolution the OEM ones are excellent and if you want more spark go buy a twin power, but the NGK ones generally last longer than an engine from what ive seen.

 

I ended up buying NGK Power Cables
NGK quality but better than the stock ones.
Also, while those get in, I had to put a set of Denso Iridium Racing Plugs. They have a lower resistnace than the standard NGK plugs and diminished the arcing from the wires, to the point where it now starts and drives.

If resistance in the calbes or the plugs was good for performance why do racing plugs don't have a resistor?

Denying that resistance in the conductor of the electric energy that will ultimately produce a spark as it jumps between the center electrode and the ground one, is stupid.
Resistance is the oposite of conductance. You must use energy tio overcome resistance, energy that otherwise would be used to create the spark in mention.

If OEM was enough, then lets all keep using the OEM air filter, OEM tires, OEM brake pads, OEM exhaust, OEM ECU's. Bottom line is that OEM manufacturers have priorities:

Reliabilty (to avoid warranty claims or lawsuits)
Cost (to fill their pockets)

The best possible performance is not at the top of their list. If such was the case, the aftermarket bussines would not exist. People would realize that OEM performs better and stick to it.

Improved performance is not only meassured in HP. It can also mean reduced emmisions, improved mileage, smoother running etc.

I have to pass smog test and HC levels in a rotary are always high, if I can help the air/fuel mixture ignite better and more throughly, I'll be happy.

OEM cables use technology that's many many years old. Why stick to it?

 

Oh, and by the way, HKS Twin Power is crap. For more power Buy a Jacobs FC 1000.
I can tell. I've used both.

 

if resistance was everything,, youd be back to copper plugs and solid wires .. but since your engine will consume copper plugs at a fearsome rate ,, and the wires would interfere with any ECU .. then you have fine wire electrode plugs with a rare metal coating ( at a compromise of material strength/ resistance )
and you also have an inbuilt resistance in either plug , lead or both ----- to suit the ecu,, and electronic equipment in a fair radius

i use non resistive bike plugs ,, platinum/palladium .. with the bosch generic 8mm leads
..and i can still turn on street lights thats have faulty starters when i pass beneath them

its a good job the ecu has some inbuilt noise reduction and filtering techniques

everywhere there is give take and balance... i need a damn good spark cause i use LPG fuel...
so plugs wires and coil dwell are all balanced in combinations that push just far enough but not too far
-- dwell on LS1 coils is 4.5 ms // not too much that i run out at higher revs // not too much that it overheats the coils // enough to fire this mix at 18 psi
wires are ballasted, cheap and easy to replace when done.. not killing days wondering if they are Ok or not,, just replace and be sure //
plugs are racing bike plugs.. cheap compared to mazda ones.. they leads have just enough ballast resistance to keep the noise sane
--but not super duper iriduim.. and for a reason --
previously ( on three separate occasions ) i have seen two popular brands lose the fine wire tip into the engine ....

and same,, for the cheap copper bike plugs ( NGK B8ES etc ) .. copper expands . fast .. with flooded plugs this can amount to a bit of the porcelin coming adrift....


.... it takes 20 plus years and lots of fuckups to amass this knowledge.. take from it what you want .. you have been pre warned

 

change your spark plugs , If the coils don't fire the plugs they might not be collapsing properly , If they don't collapse proper they can't recharge for the next fire . These guys are correct in saying there is to much talk about plug wires . I have tried old wires from an ( ordinary application ) and they worked just as well as a new expensive set . JMO have a good one Gerald m.


I use 2 trailing coils for my leading set up and they fire very hard.

 

two of my trailing wires are at 160 and the other 190 ohm. is that bad?

and my leading wires are at 120 ohm.

 

Throw that dam ohm meter away and like they said if in doubt buy new reasonable priced wires . you can buy a whole set of v8 wires for 50 bucks .

 

 

They are supposed to be 16k per meter of length. I gather your numbers are missing some zeros such that when you say 160 you really mean 16k or 16,000 ohms.

 

yeah i am. im sorry. ill more specific next time.