Like the topic says, when the ecm is above 1400 RPM or so and there is around 50 kPa or more of MAP, the PCM basically goes async at all times. IOW, higher rpms/loads = async fire. Idle (if specified) and low MAP/RPMs (if BPW long enough) = sync firings.

Why so? Is it a trade-off to prevent the injector duty cycle from becoming excessive? Its a well known fact that these stock TBI injectors are a bit undersized to allow for low load drivability. None the less, if this is so, its an interesting stratagy to get around the problems of high duty cycles. Thoughts?

 

Some of the $0D calibrations, mostly the V6's, go asynch immediately off idle. I have seen little to no difference in tweaking the switchover point in firing strategies as it relates to throttle response. The asynch routine performs well. JMHO.

 

Huh. I definatly see some good reasons to do it. I wonder how it works at high rpms. To me it seems like it could cause rolling AFRs as the manifold dries out between injector firings. Ill definatly have to experiment with it. Might be a good tool to avoid having to use ultrahigh pressues to get the DC down.