Interesting/Annoying 3rd Gen Problem.
 

So I am just writing this out there to clear my thinking...

So the RX-7 is having some really hard times starting, which is why I think my ignition system is weak, or failing. My thought of the matter is there is too much fuel being dumped on the spark plugs and it is essentially flooding the car before the spark can create the detonation.. So my thoughts lead me to the HKS Twin Power for the 7, which is an ignition amplifier. It will provide about 2 times the current to the coil packs, and increase the duration of the spark. This along with hotter spark plugs, factory is NGK BUR7EQ-P trailing and NGK BUR9EQ-P leading so NGK BUR6EQ trailing and NGK BUR7EQ leading, should clean up that problem.

Something new that happened after I installed the twin power. The car started great, however that was just misleading. After driving it it died and almost left me stranded... But now whenever I try to accelerate it will cut up bad, but only under boost. Now I am thinking it isn't necessarily an ignition problem, but it could have to do with vacuum, the MAP sensor, or possibly my sequential system is being retarded...

Ok so the MAP Sensor is good, but at idle that car has 13 in/hg...aka...vacuum leak. Tomorrow I am going to play with ether, or flammable brake cleaner, on the vacuum connections, mainly the solenoid pot...

I would stick with the 7&9 plug combination. And avoid extended idle time and short runs with the engine that tend to load up the plugs.
Barry

Did you find the vacuum leak?

Im yet to see a vaccuum leak other than the map sensor vac line coming off cause anything similar to your problems. Listen to Barry and put back in the 7s and 9s all the way around. If you are running full exhaust and other mods I would run 9s all the way around.

Theres a reason why its breaking up so don't keep doin it or you'll be buying a rebuild kit. I know problems are annoying, but you fix the weak points and you got yourself a bad ass RX7!
Anyway, Have you changed the plugs? Rx7s Have to run rich, especially when ported, single turbo'd out, and premixed. I have to change my plugs like once every 2 months! But its worth it. Things to try: (not knowing your car or your knowledge, always check the stock vac lines first) Trying regrounding your engine. This actually worked for me. If you do have a vac leak and can't find it, its possible to cap off your intake to the turbos (with the car off ofcourse) and put an air compressor into your engine. (15psi) Sometimes this works. One really hard vac leak to find is the brake booster check valve. This happens and its a bitch to find. Its in the bigger vac line going to your brake booster. Take it out and blow through one side. Its a one way check valve. Well good luck , just trying to help you out. Where are you from?

There was a vacuum leak on the purge solenoid, so I replace a few lines. Also the boost problem was my ECU was trashed. I borrowed an ecu from a friend and the car boosts great. This weekend I am going to check the coolant temp sensor, because the car is still very rich. I know they are supposed to run rich, but 10.5 A/F ratio on the factory ecu rich? Also going to put new 9's all around, with 8.5mm MSD wires. I have the twin power installed, and I hope this will fix a few issues.

Thanks for all the help.

Cheers,

Matt

Oh I am from Huntsville, Alabama.

might want to try a compression test since you will have the plugs out.

Glad to hear you got things straightened out. I'm actually in Huntsville right now on business. I leave Monday, but will more than likely be returning in the weeks go come. Hopefully I'll see your 7 around. :D

Well I managed to destroy at least on of the coolant seals on the motor. It makes me sad, especially since this was an Atkins rebuild with only 14,000 on the engine. Well i suppose I will either get a engine built, or maybe stumble upon something, either way the 7 will be down for a while.

If you do need a rebuild, take to Kevin at http://www.rotaryresurrection.com/ .

Sorry to hear about your misfortune man. :( I didn't want to jinx you, but I had the same exact symptoms (as far as trouble starting) when my coolant seal(s) failed. Hopefully you didn't overheat any housings, otherwise the rebuild will be considerably more expensive. In any case, best of luck with whatever you decide to do. :icon_tup:

I am most likely going to go that route. The thing is I didn't even get this engine warm, and it has barely been past the break-in period. Regardless, it does have 3mm apex seals, or is supposed to, so I can get a street-port and get it cleaned up. Hopefully there isn't anymore damage.

Cheers,

Matt