Need new ignition setup on my FD??
 

I have a 1993 FD and just recently finished installing a gt35r, V mount, Full 3" exhaust, Dual in tank walbro 255's, KGP primary and secondary fuel rails with 850cc and 1600cc injectors, and AEM ems. Had the car dyno tuned and on premixed 100:1 93 octane fuel it put down 420whp @ 14.5psi. I ran the car for three days then while pulling hard in 2nd gear it felt like it lost nearly all power. Runs rough and stutters now. The car has brand new plugs and although the plug wires and coils test good with an ohm meter I still think my problem is ignition.

My question is what ignition setup would you recommend? Im leaning twords the M&W pro-14r cdi but am still unsure on what coils I will run. I have read that some people are using LS1 coils. This would be convenient because they are cheap and I know where I can get a set. When I looked up the wiring schematic for these coils however, I realized they have a 4 pin plug. The wiring diagram for the M&W cdi only shows 2 wires running to each of the four coils. I want to know if anyone has used this setup before and if so how you went about wiring up the coils and cdi.

Any help would be much appreciated, thanks...

I suggest you start by searching for threads on this topic in the Single Turbo section. I don't have any personal experience at those power levels but I know there are plenty of people on here with stock FD ignition and a Twin Power w/o issue.

What kind of AFR are your running? Who did the tuning?

Consider spending more effort on diagnostics. Blaming the ignition without any evidence sounds fishy. Are all your plugs firing? Seems more like a boost issue than an ignition problem. Congrats on a nicely prepped motor tho.

Could possibly be you ignition coils are spark plugs but I would have the engine pulled to get a better look at it.

Ok, I will do a few more searches and see what I find. The engine is a Mazda remanufactured one and only has 7k on it. There are no abnormal noises coming from the engine. When the car decided to fail I was driving it and could tell that it wasn't a mechanical failure, defiantly electrical. And I tested my coils plug wires ect, and they all bench tested good. But thats the thing about ignition systems and coils in general, when they are under load they will behave differently then when they are not. I just short of positive that the problem is one of my coils, if not more than one. Plus, everything else on the car was checked over when I did the build and most of the bolt ons on this car are in new condition. The ignition system is the only place I spent almost no money or time. just replaced the plugs and thats it. The plugs spark when they are grounded at idle. But if I pull them out after a 2nd or 3rd gear pull, they are wet with fuel.

Christian Alexander with EuroTrix in Union MO is the guy that tuned the car. I belive he set the AFR up a little on the rich side, like a 12.8 or 12.9

Anyone have experience with the M&W or the ls1 coils? Thats really what Im asking.

Well given that it's a freshly tuned motor, I'd start with a compression check.

12.8-12.9 isn't very rich for an FD under load. I'm not a tuning expert but there are great threads in the tuning and 3rd gen sections about tuning a turbo rotary.

As for ignition, for $40 you can diagnose it positively - get another set of stock coils and change them out. I've bought sets of coils for $40 on this forum. You might also need to replace the ignition coil harness, which was updated in design after 1995.

David

compression was good in all thee chambers on both rotors @ 87 psi so im thinking the motor is good....

That's good news.

I'd try a spare set of stock coils to verify that gets things working correctly and check the ignition coil harness for shorts.