too much spark advance at startup
08-13-2006, 05:22 PM
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Car: '87 Camaro LT
Engine: 355 L98
Transmission: T56
too much spark advance at startup
I converted my L98 from carb to LT1 intake with a speed density setup. With the carb it liked 12° base timing so that's what I'm using with the EFI. At startup it will just crank and won't fire. I either have to disconnect the timing connector or retard the base timing for it to start. If I reconnect the connector after the engine runs a minute or two then the car will restart fine. If I leave the base timing retarded the car loses a lot of power driving around. What are my options? At startup does the ECM use the main SA table or just the SA vs. temp table? The main SA table adds about 20° at idle speeds, I could lower that maybe.
This is my main spark and startup spark vs. temp table:
This is my main spark and startup spark vs. temp table:
08-15-2006, 09:59 PM
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Car: check
Engine: check
Transmission: check
Something doesn't seem correct. Disconnecting the timing connector shouldn't affect cranking SA. Maybe the module is bad? The distributor should fire at the reference pulse until the ECM tells it otherwise. Which is typically once the engine reaches 400 RPM.
I would set the base (or initial) timing to where the engine starts. Also set that value in the BIN. That way none of the running timing changes from what it is currently set to.
RBob.
I would set the base (or initial) timing to where the engine starts. Also set that value in the BIN. That way none of the running timing changes from what it is currently set to.
RBob.
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