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Old 04-29-2019, 12:11 AM   #1 (permalink)
harbin9er
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Join Date: Apr 2013
Location: USA
Posts: 6
Drives: 2008 G37S
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Question FI-TT with UpRev tune: cranks but no spark nor fuel?

Hey folks, I am running into a road-block with my install. Does anyone have an idea about this? thanks

I have a 2008 Infiniti G37S 6MT, which I am currently in the middle of installing a Fast Intentions https://fastintentions.com/ Twin Turbo kit for. The ECU tune was made by sebastian@specialtyz.com for this application using UpRev.

I have my own UpRev cable and license. After flashing Sebastian's tune into the ECU with UpRev's RomEditor, I can crank the motor, but it does not start. Below are the results of my diagnosis so far:
  • My ECU ROM number is: <23710 - JK75D>.
    However, Sebastian gave me a tune for " JK78C", but assured me that JK78C is the updated ROM and this is what UpRev has been using for my ECU for a few years already.
  • Checked all fuses - none blown
  • Checked all wiring harnesses- all OK and connected
  • The following were checked using both <Sebastian's JK78C tune>, as well as the 'OEM' <JK78C.OsirisROM>, which was downloaded with UpRev's RomEditor:
    • NO SPARK
      I physically checked this during cranking with an inline spark plug tester. However, there was 12V across two of the three terminals (the third terminal is ground, I assume) in the connector that goes into the coil pack - this would indicate that there is no physical wiring issue.
    • NO FUEL INJECTION
      I physically checked this by pointing an endoscope into an open spark plug hole, as well as putting a stethoscope onto a fuel injector to listen for clicks during cranking. However, I know the fuel pump works (it whirls up at key-on), and I do get fuel pressure (physically measured by fuel-pressure gauge) into the rails (there is fuel all the way to the injectors when I disassembled it).
  • Searching in internet forums, there were some similar 370Zs/G37s "crank, but no start" issues. They've found the problem was due to a bad crank angle sensor. However, I didn't touch the crank sensor during my install, but I did have to change to an aftermarket flywheel. Furthermore, I logged some data using UpRev's RomEditor and I do get reasonable Engine RPM readings (it goes up to ~150RPM during cranking). This seems to indicate it's not bad crank sensor.
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