Hey everyone i have a lil problem heres a lil background on my car first
1987 Mazda RX-7 GT Limited Turbo

Engine
Brand new S5 Turbo Engine built by Joe at RPM Performance in Ontario (literally has 3km on it)
Aggressive Street Port
RX-8 Eccentric Shaft
RX-8 Stationary Gearing
Brand new Irons and housings
Every Seal, Spring and gasket replaced
Brand new OEM oil pump
S5 Turbo and manifold with upgraded fan blades (spools awesome and no shaft play)
550cc Primary injectors/ 720cc secondary Venom injectors
255lph Walbro Fuel pump
HKS FCD
Blitz BOV
Brand new NGK plugs from Mazda
3” Turbo back exhaust with pre-muffler
K&N Air Filter
Electric Fan

Drive train
JDM tranny with 75000km
2 way LSD
OS Giken twin plate clutch
OS Giken 12lb flywheel
New slave and master cylinder in January 07
New Release bearing

Footwork
KYB AGX shocks (really stiff)
B&G lowering springs
Cusco Strut Bar

Rays engineering Gram Lights 17x8
BF Goodrich G-Force KDW on the front
Continentals on the rear
EBC Cross drilled rotors

Exterior
Aluminum T2 Hood
Repainted in July 07 RX-8 Pearl Red with Gold flake All trim painted for S5 look
RX7 GTX front lip
Side skirts
GXL Mirrors
S5 Spoiler
S5 Tail lights
DOT approved Sylvania head lights

Interior
RX-7 Savanna seats
Converted from 2+2 to 2 seater
Greddy turbo gauge
Sard turbo timer



Now here is my problem, i can start the car and it runs quite rough as if running rich, fair amount of grey smoke, the car will run for about 5 minutes then dies. I pull out the sparkplugs and the top ones are soaking wet but the bottom ones are fairly dry, i cut the fuel and check for spark and all plugs have spark when grounded to the alternator, I am completely lost can somebody please help me!

 

Oh yeah the car is rhd if i didnt mention

 

please... anyone, like im lost

 

It sounds like the trailings are not even firing.


-Ted

 

k so i checked and there is spark at all plugs, and the bottoms are slightly but definatly not as fouled, the spark is a bright yellow/ orange. I still am looking for answers

 

please someone help i dont know what to do

 

Are you sure the injectors are plugged in right? Or are your 720s misplaced in the primaries place? Who put the engine in the car? Running on Stock ECU?

 

Yeah, I don't see anywhere in your mods how you are controlling your air/fuel.

 

im not running anything for fuel control i was told stock ecu can hadle these mods, the previous owner installed the motor, now witch fuel rain should the primary injectors be installed on higher or lower rail.

 

Yeah, sorry, the stock ECU cannot use the bigger injectors. It is configured for 550cc injectors and will be running stupidly rich with the bigger fuel pump and injectors. You should look into atleast getting an Rtek which can utilize the bigger injectors and give you some fuel maps for higher PSI.

 

Wrong, well, not at startup, usnless you switched the primaries with the secondaries.

Secondaries are on the top rail. Be sure also that the injectors are plugged in right. I mean right injectors with the appropriate plug.

 

Sorry, I meant the injectors would affect it during driving, but the bigger fuel pump would cause it to run rich at idle and throughout the range if not controlled, correct?

 

Just an Observation,,seeing I know DICK about TII's..OK..If you Put On Bigger Injectors,than what the ECU is used to,will the ECU not just give That injector the Same Duty Cycle as the Other Smaller injector..Meaning you would be getting MORE Fuel than Normal..Especially If you Jacked up the Fuel pump to a higher capacity Flowing Pump.?.so Is That Not WHY Guys OPT for a Fuel management unit..to Control the amount of Fuel to the engine?.,To correct the fuel flow,so that the engine doesn'T GAG with Fuel,due to the Bigger Injectors..(Primary rail is the first rail to get fuel after the Filter.).I don't want to sound like an Idiot,so If I am wrong Please correct me,Or INFORM me so that I will Learn more about this.Thanks..NO mean to Hijack just adding my .02 as Mentioned.Thanks.

 

Well, you are wrong.

On start up, the stock ECU uses a different preset map, until the AFM kicks in, so the 550cc are just fine to start it up, even with a 255 walbro fuel pump.

 

hey i opened up a new thread with a full update by accident, i couldnt find this one my bad but all the info is in it.

 

I have a suggestion..It Is FREE,dosen't cost anything!.Take a Pair of Insulated Pliers.Now when the car is Running,Take off One of the Trailing wires.look for spark.Then Do the Other one..could be a bad Trailing coil.(saying this because I had rough idle,couldn't track it down and that is what it turned out to be.I changed the Coil,wires and plugs,,It Came "alive"!)..Thanks F.C.3S.for Politely telling me I was Wrong...also Question..Are the injectors the Right Impedance for the ECU that you are using?..This is Just throwing stuff out to ponder over..I hope you get it going though.

 

ok so 1 of the oil injector lines was clogged so i have changed that and am still having the same problem i am ready to burn this car the "heat" light is on but i think that is because of the aftermarket exhaust, please someone help!!! also does the fcd make it so my fuel wont cut out at 7500 and how do i remove it who ever installed it did a hack job

 

the fcd is to stop the fuel from being cut to the rear rotor when you up the boost. to my knowledge it does nothing with the rev limiter.

also it wasent really clear in your post, is this a new problem that just started? or did you buy the car in this condition? also from the sound of things, even if you fix this problem you are going to have more down the road for sure.