The ZR5 box was external. It was triggered with a digital output from the ecm... it turned on above a specific TPS and turned off below a specific TPS.
The ZR5 box was external. It was triggered with a digital output from the ecm... it turned on above a specific TPS and turned off below a specific TPS.
Interesting! So it was just like a module wired into ecm?Originally Posted by 1project2many
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Found diagrams to double check. ECM engaged relays on power side of injectors to bring them online. Secondary injectors shared driver with primary injectors. 1228331 /1990 LT5 wiring diagrams thanks to "Tyler Townsley" of corvetteforum.com:
http://www.sirgalahad.org/tyler/misc/90ecm1.jpg
http://www.sirgalahad.org/tyler/misc/90ecm2.jpg
http://www.sirgalahad.org/tyler/misc/90ecm157.jpg
http://www.sirgalahad.org/tyler/misc/90ecm158.jpg
http://www.sirgalahad.org/tyler/misc/90ecm159.jpg
http://www.sirgalahad.org/tyler/misc/90ecm160.jpg
http://www.sirgalahad.org/tyler/misc/90ecm161.jpg
An electronics idea I have to get the secondary injectors to work progressively is a 555 timer IC ( http://www.ti.com/lit/ds/symlink/lm555.pdf ) to turn on the secondary injectors based on the pulse with of the primary injectors. Something similar to a watch dog timer?
dave w
If you can distinguish between AE (fuel delivered due to air density change in plenum) and load based fuel (fuel delivered due to air mass delivered to cylinder) you might have a workable approach. I found a copy of LT1 / 8051 code hanging around thirdgen. If the fueling routines could be worked out (no apparent AE tables) and duplicated in the P4 then you might be able to use a very simple circuit to follow the primary injector.
you could build or buy one of these, wired to the secondarys, and just use a relay to put power to it when the secondary blades open.
http://www.jbperf.com/p&h_board/
1978 Camaro Type LT, 383, Dual TBI, '7427, 4L80E
1981 Camaro Z-28 Clone, T-Tops, 350/TH350
1981 Camaro Berlinetta, V-6, 3spd
1974 Chevy/GMC Truck, '90 TBI 350, '7427, TH350, NP203, 6" lift, 35s
I'd like a copy of that please!
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Haha! I think you posted in the thread it was in! I need to find the link as I forgot to save it on my pc last night.
I've got one a guy did but it is in several pieces and not completed. One of these days I'd like to learn this but the time it would take is probably not going to happen unless there's a dissesembler and commenter button?
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
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