Uchinan

Question:
My S14 SR idles great when the MAFS is not plugged in, just like it should (running off the TPS) and it doesnt go past around 2500 RPM. And when I say great, I mean it idles and starts perfect. But when I plug in the MAFS the engine shakes, heavily drops the RPMs (and becomes very erratic as if the timing is off), and seems to be running rich based on the smell of the spark plugs and exhaust. Any ideas about the root cause of this?

Background:
Sorry to be longwinded, but here is the situation to let people know how I got here. I did the typical '95 240sx to S14 SR swap. The 240sx is mostly stock, and the engine, except for the FMIC, blitz SUS intake, and Exhaust, is stock. I did the swap and all the wiring myself, according to the S14 Manual, and I am pretty sure about all the wires since I have checked each one individually for continuity with its respective plug. I have tried 2 MAFS, 2 ECU's, re-wired the MAFS independantly to the ECU outside of the harness, retimed the Engine twice set to TDC, and checked the resistance of every sensor on the vehicle according to the 95 S14 FSM. This problem seems to be unfixable, and I would love it if someone knew what was happening, because this is the toughest SR problem I have ever encountered. Thanks

Wires Connected on the F4 - M63 couple:
-TACH
-Water Temp
-Speed Sensor
-Neutral Sensor
-Fuel Pump
-MIL
-IG Power
-STSW
-IACV-AAC
-(+B) Power
-Injectors and IGN Coil Relay are both connected to the IGNSW power source (main black and Red wire)
- Wiper stuff (which is almost entirely the same on the harness)

juztinvez

just throwing this out there. my sr came with a s15 mafs i wonder if you got the wrong mafs and it is sending a higher signal causing the ecu to think there should be more fuel. good luck i'm on my second mafs and those problems definately suck a fatty.

Justin