DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
Hi I have been reading up on Dfi systems. And the accel dfi 7 uses a dual sync distributor to run sequential injection....how is it possible to do that without a cam sensor ?
please educate me
__________________ 1988 GTA. trickflow 64cc cnc heads. crane 2032 cam. All smog and cat delete.
In the absence of a cam signal, the DFI operates in a "random sequential" mode. It follows the firing order sequentially, based on a known crank signal pattern.
It's not recommended that you run this way intentionally. However, you still get the benefits of sequential: less fuel rail transients, individual cylinder fuel control...etc. If you are thinking about running sequential, definitely get the Dual Sync (or some other) sequential distributor.
wouldent a system like electromotive TEC3 be a better option since it have "real" sequential. With a high resolution ignition and a cam sensor. Their system looks very much like LS1 teknology. Not many people uses their system is their something about the accel that makes it the most desirable ?
I don't know much about the tec3. However, I don't think older tec units could use stock cam/crank signals, you had to bolt on their crank trigger contraption. Don't think this has changed w/tec3, but I haven't used one yet either.
The DFI unit is software-configurable for many types of cam/crank/spout combinations. Either pick a predefined combination (Chevy HEI, Buick GN Coil Pack, Ford EDIS...etc), or select the cam/crank/spout trigger edges and signal levels that you want.
You misunderstand about the random sequential stuff. It is more like a failure mode such that when you are running "true" sequential, and you lose your cam signal, your motor doesn't quit. You can still drive home. The dual-sync distributor gives both crank and cam position signals to provide "true" sequential operation.
Technically the second pick-up in the dual pick-up distributer would be a cam sensor, it just does read the cam directly, but a part driven off the cam, like the newer s-series trucks, don't know what year they started with it, but I do know in '99 it has a cam sensor used this way.
