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Thread: Terminator EFI rich at idle?

  1. #1

    Default Terminator EFI rich at idle?

    I'm running a Terminator EFI on a Chevy truck with a 383 stroker and a Roots blower, which has been treating me great until recently. The truck was down for a few weeks while I was doing a transmission swap. Now on startup it surges pretty good and AFR is going between 10-11:1, and I'm getting some black smoke from the exhaust. Off idle it seems to run fine. Last time I pulled it in the garage before pulling the transmission, it stalled which was odd, but I thought nothing of it at the time. Haven't had much time to look into it yet, but figured I'd get some advice on where to start. Was initially thinking WBO2 sensor, but if it's reading 10:1 shouldn't it be pulling fuel?

  2. #2
    Join Date
    Dec 2009


    Diagnose The Following:
    All sensor values correct on Data Monitor?
    Failed WBO2 sensor corrupted Learn Table (unusual %)?
    Exhaust leaks upstream of the WBO2 sensor?
    Sufficient length of exhaust piping beyond WBO2 sensor?
    Ignition misfire? (WBO2 sensor will read lean.)
    Battery/charging system functioning properly?
    Consistent fuel pressure? (Disconnect vacuum hose to measure static psi.)
    Inspect wire harness/connectors for damage and ensure it's not near any high voltage components.

    At key-on (initializing) and heating, the WBO2 sensor "LED" status indicator is yellow.
    Then there shouldn't be any "LED" status indicator at all (especially when engine is running).
    The WBO2 sensor heating cycle will time-out (key-on/engine-off) if the engine isn't started.
    When the WBO2 sensor heating cycle times-out (key-on/engine-off), it will display "init". (Sensor Diagnostics & Statuses) (Ensure battery is fully charged!)
    Key-on/engine-off & cold, the NTK WBO2 sensor displays about 29:1 AFR. The Bosch WBO2 sensor displays about 35:1 AFR.
    After turning the engine off, exhaust gases need to dissipate before seeing these full lean AFRs (key-on/engine-off & cold).

    Troubleshooting & Testing: (Sensor Diagnostics & Statuses) (Holley EFI Wiring Manual & Diagrams) (Troubleshooting Checklist - Holley EFI) ("Test Relay" for troubleshooting/diagnosis.) (Wideband O2 Sensor Test/Diagnosis - it works!)
    If testing the WBO2 sensor key-on/engine-off, the sensor heater will time out, so you'll need to work fast.
    If you need more time, the WBO2 sensor test can be performed with the engine running in Open Loop mode.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 MT tires.

  3. #3


    I finally got all my idle issues fixed by first checking MAP at idle, then manually tuning my percentages in the Coolant Enrichment Table down to 100%. For some reason, the cooler than 180° was WAAAY off causing me to have 9-10:1 ratios. Once I manually tuned them down to 100% I now have consistent good idle and good AFRs, even from a dead cold start.

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