Morning,
Here's the engine build for reference:
- 2004 GEN 3 5.3L.
- Drive by wire throttle body (DBW).
- Elgin 1840P (SS2) Cam with 0.585/0.585 valve lift. See attached for cam card information. Cam installed straight up.
- Exhaust dumps roughly 18" from manifold, and have some minor baffles within them to muffle noise.
- Only using front O2 sensors, which are installed in the stock location.
- Using Innovate LM-1 Wideband O2 sensor, which is installed 6" from Bank 1 O2. It is not being recorded, only viewed on the Innovate display.
- All engine parts are stock, such as intake, sensors, throttle body, heads, etc.
- Plugs and wires have been replaced.
- Injectors were originally stock #628 and have been replaced with ones flow tested 80lb/hr at 58 lbs.
- Fuel rail system is stock returnless with an inline fuel pressure regulator setup for return to the fuel cell.
- Fuel pump system is an external Walbro 255 with deadhead pressure at the rail set to 58lbs.
- Stock wiring harness was modified for standalone operation.
- The ECU is stock.
- The DBW controller is not original, but one pulled from another vehicle (issue?).
- Stock five wire MAF is installed in order to obtain IAT signal.
- Air intake is a short section of intake tube with MAF mounted
- ECU tune is as follows:
* SD tune with MAF set to fail (using HPT guide to SD tuning)
* Was with stock and 80lb/hr injectors
* Ran the Russ K Idle config, and idle remained relatively
With the engine running on a test stand, the engine's status and issues are as follows:
- Either running the stock and new injectors, starting cold or hot, the engine idles well down to 800-850 RPM.
- Increasing the RPM must be done slowly and gradually or else the engine will jump up in RPM.
- Any minor blip in RPM will cause the engine to surge, hunt for 5-7 seconds, and die.
- While in Idle, I have noticed that the STFT's increase to +30%, so using the Wideband as a reference I use RTT to trim up the fuel in the Idle cells. The fuel trims go quite high and the STFT's do not come down enough.
- I have attempted to trim/add fuel during throttle increases, but the engine's RPM cycles too quickly to adjust properly.
The attached tune is as I left it last night with minor additions from the HPT SD tuning how to.
The scanner log:
- SD-RTT-SS2-80_RussK SD_00
* Slight throttle increase at 2m50s mark
* Throttle blip and dies at 5m45s, 9m25s, 11m55s, 15m38s marks
* Hot start at 6m45s, 10m56s, 13m35s
- SD-RTT-SS2-80_RussK_00
* Ran the Russ K Idle Config
That's about it.
I hope that someone can take a look at the info and guide me in the correct direction. It would be greatly appreciated.
Thanks!