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Old 09-21-2010, 05:38 AM   #1
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Default Car starts but engine won't rev

I have a 1990 1.6 turbo Miata. We tried starting the car yesterday after installing the AEM EMS and it fired up. However, the car will only idle. When I try stepping on the accelerator the engine bogs down. Iíve tried different settings for the ignition and injector phasing and the idling would improve but the engine still bogs down when I press the accelerator. It seems that there is not enough fuel or that the timing (injector or ignition) is out of sync. Right now Iím running the injectors by batch firing through Inj#1 and Inj#2 of the EMS. Should I re-wire to make them fire sequentially? Here is a list of components I have on the car:

Greddy turbo w/ intercooler boosting around 1.3 bar
AEM 3.5 bar map sensor
AEM AIT sensor
RC 440cc injectors
Nissan 200SX TPS
OEM CAS (4 tooth I believe)
FM knock sensor
Bosch O2 sensor

I used to have a Miatalink ECU on the car, but I decided to get an AEM when my old ECU failed. I hope someone can help me here.
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Old 09-21-2010, 09:23 AM   #2
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Yes
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Old 09-29-2010, 11:44 AM   #3
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I found that my injectors would go super lean when I tried to accelerate from idle. I fattened up the fuel curve in the cells above the idle and no more bog.
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Old 10-20-2010, 11:44 AM   #4
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Ok, so I wired the injectors to fire sequentially. Basically I separated Injectors 1 & 3 and Injectors 2 & 4, and connected them individually to the AEM EMS (Inj#1-2U, Inj#2-2V, Inj#3-2Y and Inj#4-2Z). When I went to the Injector Menu to activate Injectors 3 & 4 I noticed that Injectors 9 & 10 were active on the menu. So I checked Injectors 3 & 4 and unchecked Injectors 9 & 10, since I wasnít using them. When I tried starting the car the engine cranked then stopped, and it felt like a hydro-lock. I removed the spark plugs and sure enough cylinder #1 was full of fuel. I removed the fuel from cylinder #1, went back to the Injector Menu to make Injector 9 & 10 active (since it didnít flood when they were active) and proceeded to start the car. The car fired up, but idled rough. I decided to pull out the sockets of the injectors to see which ones were active. When I pulled off the sockets of injectors 1 & 2 the idling would not change, while when I pulled off the sockets of injectors 3 & 4 the engine would stumble and almost die. Seems that injectors 1 & 2 are not working. What should I do? Should I try connecting injectors 1 & 2 to a different driver (maybe Inj5 & Inj6 or Inj7 & Inj8)? Why does Inj9 and Inj10 have to be active to prevent cylinder #1 from flooding? Can I deactivate Inj9 & Inj10 once I transfer Inj1 & Inj2 to a different driver? Has anyone encountered this problem with the AEM EMS? All input will be much appreciated.
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Old 10-20-2010, 12:12 PM   #5
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In regards to your issue... did you setup the nissan TPS like it was setup in a seperate thread to make it read properly?

once you do this, compare the miata tune to the nissan 240sx tune and copy the values over for the tps based things and work from there... my tuner when i told him 240sx tune mentioned there shouldnt be a huge difference between tps variable things and miata and it was a great point to start. so maybe try that.


also when you say bosch oxygen... i want to clarify you mean wideband o2?
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Old 10-20-2010, 12:44 PM   #6
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Setup the Nissan TPS and it works fine. The only thing I didn't do was modify the TPS input so it doesn't read 0% when the throttle is closed and 100% when the throttle is at WOT. The thread recommends to set it at 1% to 2% when closed and 98% at WOT. Also I just have a standard O2 sensor connected, not a wideband O2 sensor.
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Old 10-20-2010, 01:28 PM   #7
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get a wideband so you can tell what its doing first off, set your throttle range and then copy over the TPS values from a nissan in regards to:
-tps accel
-accel mod
-dtps accel
-throttle injection corr
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Old 10-20-2010, 01:47 PM   #8
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Quote:
Originally Posted by jmcamus View Post
Also I just have a standard O2 sensor connected, not a wideband O2 sensor.
Let us know how that works out for ya.
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Old 11-06-2010, 02:31 PM   #9
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Change to the CA 1.6 calibration because those run sequential.
Make sure VVC #1 and #2 are disabled because they use inj 9 and 10 as outputs.
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