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1JZSC Bill · 04-14-2017, 12:08 PM

Hello, I know this is my first post but I've been stalking these forums for over a year now and I decided to bite the bullet and make an account since this has stumped me beyond my knowledge.
I know this topic has been brought up many times as I have searched and found many topics that are somewhat related to my problem but they all have a factor in them that is far beyond what mine has. (Ex: SAFC or frayed wires ETC)

Ok, so... I have just finished my Blacktop SR swap into my s13 hatch and everything ran fine. I replaced the TPS and set it to .46, replaced the water temp sensor, replaced the O2 (fat type), repaired a burnt trace on the ECU, and replaced the MAF twice. My problem I believe is the MAF since I started the car with a SOHC KA MAF and the car ran rich but it ran decent enough to test drive it up the street although it was unburnt fuel black smoke for days. When I unplugged the MAF it idled high so I bought a new MAF hoping it would fix it. The SOHC MAF also had paint all over it from the previous owner so I believe it might have paint in the sensor (not sure). When I got my new MAF and plugged it up it ran better than ever. The car had been started about 4 times on the new MAF and idled, revved, but never driven on it. Finally when I went to drive the car on the new MAF as I was backing out of the driveway the car was doing good until about 1/2 way down then it just died like it was too rich. I tried multiple attempts at starting it and it would start for a whole 10 seconds or so then get rich and die. I thought the new MAF went bad so I contacted the seller and he sent me another replacement. Upon receiving the replacement I installed it with no success, it still idles rich as hell then stalls out. Also a final note when you unplug the MAF the car runs fine and it allows me to rev to about 2500 or so as I was told it should before reaching limp mode cut.

A few notes and Info:
-Wiring harness is a Wiring specialties Harness
-Motor is an s13 180sx Type X Blacktop with a J4 ECU
-New TPS, Water Temp sensor, and Fat type O2 sensor
-ECU has a burnt trace on the little white ball looking resistor but I soldered it and it took solder so I believe its good
-The rest of the ECU looks fine and doesn't have any discoloration or burns anywhere else
-Deatschwerks dw200 fuel pump
-300zx Fuel Filter
-FMIC
-3" turbo elbow, 3" downpipe, and 3" to 4" tip blast pipes
-ISR metal turbo inlet pipe
-no Vacuum leaks (tested with propane and tested each line by itself)
-New NGK Iridiums (Heat range 6) gapped to .28

I just cant figure out why its running so rich. As I said, If I unplug the MAF it idles fine but when you plug it in it just gets rich and dies. Could both of my new MAFs be bad? is there anything else I can do to test it? Am I missing something??? Please help!

I am sorry to bother once again and as I stated before, I searched and searched but nothing came up with the same stuff as mine. I was finding people who had this problem with a SAFC (I don't have one) and people with wiring messed up (I have a new harness) and also people who didn't set their TPS but mine works fine since if you start it with it unplugged it shoots to 2k before it dies but plugged in it starts normal then dies. Please and Thanks!

04-14-2017, 12:08 PM	#1
1JZSC Bill Join Date: Apr 2017 Location: South Carolina Age: 31 Posts: 2 Trader Rating: (0)	Sr20 Blacktop Running Rich cant figure it out Hello, I know this is my first post but I've been stalking these forums for over a year now and I decided to bite the bullet and make an account since this has stumped me beyond my knowledge. I know this topic has been brought up many times as I have searched and found many topics that are somewhat related to my problem but they all have a factor in them that is far beyond what mine has. (Ex: SAFC or frayed wires ETC) Ok, so... I have just finished my Blacktop SR swap into my s13 hatch and everything ran fine. I replaced the TPS and set it to .46, replaced the water temp sensor, replaced the O2 (fat type), repaired a burnt trace on the ECU, and replaced the MAF twice. My problem I believe is the MAF since I started the car with a SOHC KA MAF and the car ran rich but it ran decent enough to test drive it up the street although it was unburnt fuel black smoke for days. When I unplugged the MAF it idled high so I bought a new MAF hoping it would fix it. The SOHC MAF also had paint all over it from the previous owner so I believe it might have paint in the sensor (not sure). When I got my new MAF and plugged it up it ran better than ever. The car had been started about 4 times on the new MAF and idled, revved, but never driven on it. Finally when I went to drive the car on the new MAF as I was backing out of the driveway the car was doing good until about 1/2 way down then it just died like it was too rich. I tried multiple attempts at starting it and it would start for a whole 10 seconds or so then get rich and die. I thought the new MAF went bad so I contacted the seller and he sent me another replacement. Upon receiving the replacement I installed it with no success, it still idles rich as hell then stalls out. Also a final note when you unplug the MAF the car runs fine and it allows me to rev to about 2500 or so as I was told it should before reaching limp mode cut. A few notes and Info: -Wiring harness is a Wiring specialties Harness -Motor is an s13 180sx Type X Blacktop with a J4 ECU -New TPS, Water Temp sensor, and Fat type O2 sensor -ECU has a burnt trace on the little white ball looking resistor but I soldered it and it took solder so I believe its good -The rest of the ECU looks fine and doesn't have any discoloration or burns anywhere else -Deatschwerks dw200 fuel pump -300zx Fuel Filter -FMIC -3" turbo elbow, 3" downpipe, and 3" to 4" tip blast pipes -ISR metal turbo inlet pipe -no Vacuum leaks (tested with propane and tested each line by itself) -New NGK Iridiums (Heat range 6) gapped to .28 I just cant figure out why its running so rich. As I said, If I unplug the MAF it idles fine but when you plug it in it just gets rich and dies. Could both of my new MAFs be bad? is there anything else I can do to test it? Am I missing something??? Please help! I am sorry to bother once again and as I stated before, I searched and searched but nothing came up with the same stuff as mine. I was finding people who had this problem with a SAFC (I don't have one) and people with wiring messed up (I have a new harness) and also people who didn't set their TPS but mine works fine since if you start it with it unplugged it shoots to 2k before it dies but plugged in it starts normal then dies. Please and Thanks!