RotaryBred

This problem just seems to be neverending.. with so much money invested in this car so far i'm at my breaking point....



First off here are my mods:



Turbonetics T-76 Turbo

Apexi N1 Exhaust

Midpipe

Custom SS Turbo Manfold

Large Street Port

3mm Seals

MSD 6AL on Leadings (no RPM module installed)

Quad Blaster SS Coils

Tial 60mm Wastegate

HKS Seq. BOV

Koyo Radiator

Apexi GT Intercooler

ACT 6 Puck Sprung Hub Clutch

Tial 44mm Wastegate

Power FC

CJ Motorsports Fuel Rails

Aeromotive A1000 FPR

Bosch 044 Fuel Pump

Apexi AVC-R Boost Controller

AEM Uego Wideband

All emmisions removed

Single turbo harness





Here's my problem... when i first got the car, it ran fine for a few weeks. Then I started getting some serious ignition breakup problems anytime i hit boost. Under load the car would backfire and pop and it would bearly gain any speed. At this time I had only an apexi intercooler and intakes, and the N1 exhaust. everything else was stock except for the PFC and AVC-R. The problem was intermittent. I was very troubled as to what the issue was because not only was this my first RX-7, but no one could give me an answer. Eventually I found that if I moved my PFC around, the problem would fix itself. In conclusion, i shoved the PFC into the kick panel with the harness in a certain position so that the car ran fine.



Eventually I popped a seal in the engine due to adding the midpipe and getting a boost spike. The engine came out, and all of the mods listed above went in. I had one tuner start the street tuning process and stopped when he couldn't get my car past 7 psi or so without serious breakup. I decided to get a second opinion and I had my car tuned only up to 7psi because the tuner couldn't get past that without having the same problem. As soon as he hit 7psi or so on the dyno, the car would backfire and pop like crazy. I made 292whp/232rwt @ 7psi with igntion problems... not bad i guess LoL.. anyways he had no idea what was causing my problem and was no help with fixing it...



I've done numerous amounts of diagnosing and troubleshooting...



I replaced my wiring from the PFC to the igniter (running it right along the firewall instead of through the front harness).



I'm using #9 plugs all around; brand new MSD wires.



Checked for spark potential from each coil (jumping a spark to ground) with at least an inch of jump from each coil



Swapped 3 different igniters



Swapped igniter connectors



Swapped 3 different MAP sensors



Checked TPS Voltage



Checked the knock sensor



My tuner said I was getting a good signal from the CAS



Added 8 ga grounds to each housing and to the igniter



Opened up the PFC and looked for bad solder joints



Checked the coils for resistance across the points



All plugs are going the the correct coils



All coils are firing (at least when free reving, can't put a timing light on while driving)



Wideband reads about 11.5 or so consistantly under load



I'm sure there is more that i've checked, I just can't remember everything. The only thing i haven't done is swap PFCs but I don't know anyone in CT that has an extra laying around... Anyone have any ideas?

1Revvin7

Try running the car with the trailing coils unplugged and spark plug wires removed. Not a bad idea also to turn off the lights and free rev the car to see if you see anything out of the ordinary. Do you see anything strange with a timing light on the car free revving? Does it match what you are seeing in the ecu.

ryanrx007

hi there



Did you check the injectors for clogging? What injectors are you using? Stock? Might not be the ignition. How r u certain that it's the ignition.



If you're sure about the problem being the ignition, then I'm assuming also that the MSD is wired correctly. You sure you didn't swap the positive and negative from the MSD 6 to the coil? What coil are you using anyway? MSD Blaster Coil?? Check the ignition carefully for a swaped wire. You think it won't make a difference but it does........ happened before to a friend of mine...



If you can tell us how exactly the MSD is wired will help us help you as well.....



I would start from there...



I have other ideas in mind...

RotaryBred

for injectors, i'm using 750/1680s. they have been flow checked within the last 2000 miles. I'm using blaster ss coils. if i'm not mistaken, wouldn't the coils not fire if the coil leads were hooked up backwards? the MSD 6 is hooked up directly to the igniter via the leading output trigger wire. i eliminated the coil harness to clean up the engine bay. the trailing coils are also hooked up directly to the igniter.



as far as being certain it's the ignition, i've been told by 2 tuners as well as reading my AFR which stays between 11.1 and 11.5 under load. if it was a fuel issue i'd assume numbers below 10.4 since i'm getting serious backfire.

RotaryBred

i unhooked the MSD box today and tried running the car with just the coils on thier own. the car revved a lot slow and broke up at much lower boost. at idle the engine actually started to foul out the plugs as lots of grey smoke started to pour out of my exhaust and the RPMs started to drop. once i revved the engine the smoke cleared again. could all of my coils be burnt out?

sideways steve

To me it sounds like you mentioned exactly what the issue was in the first post bud ! You said that if the wiring harness was sat a certain way it worked fine. that points to a broken wire somewhere or a bad connection in the loom or connector.



My bets are on bad wiring in the main loom to the PFC, not just the ignition part of the loom. If any of the old sequential turbo solenoid wiring etc is broken or damaged in there it can cause all sorts of issues. Id replace your main engine loom and go from there, its not a hard job and may save you a shed load of time and money in the long run !

teknics

yea most problems that start "intermittently" and get worse are wiring, or a clog (have you checked your fuel pump sock? seriously had this issue, sounded and felt like ignition breakup, clean the sock and bam better)



Altho with the msd unplugged it running richer and worse leads me to think too much fuel possibly (if it isnt electrical, this would be something to look at), maybe a bad pressure regulator or something. If their is absolutely no electrical problem to the ignition i'd definitely start looking at fuel.



As for bad coils, ive bought brand new oem coils that when ohm'ed out (i am a mazda tech i know how to do it) were either on the edge or over spec, they function flawleslly. In my opinion the best test for them is to swap in a KNOWN good pair.



Don't get tunnel vision on the ignition, tons of other things can cause breakup like symptoms.



kevin.