555 EFI competition- an on topic response

[Bruce Plecan]

If you get the Sy doc., on the FTP (it's a long pdf., I forget wat the exact
name is), they list the formulea that the ecm goes thru to determine the
fueling.  The simplist way to do it is run a 555 for each stage of the
formulaes corrections.  That way you can do the CTS, MAT, MAP, etc., the use
several for like the CTS AE, TPS AE, etc.
   In this vein some time ago I posted some maps, with the injector
duarations at various conditions.
   To ease you burden. do an ecm bench as outlined at the efi site, and run
an ecm thur all it operating conditions, and you'll see how all the
parameters effect things, and the injector duration changes.  Once you have
all the injector durations mapped at all the operating variables then it
just the math to figure out what values to use on the 555s.  Yes, very time
intensive.
   Doing the power supply correctly is being covered in Gars latest
postings.
Next
Grumpy




 We spend too much money on PCMs. We have a project going to design a new
cheaper generation of EFI using a single 555 timer circuit. For our 4 cyl
cars we trigger the 555 from cyl one spark. The 555 controls all four
injectors and the amount of fuel injected is controlled by a variable
resistor that doubles as a choke for cold starting.


----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org