Older boys just have more expensive toys. I'm currently working to retrofit a modified GM EFI controller and Crossfire Fuel Injection manifold to my 1971 Camaro. The installation has begun... | ![]() |
First and foremost, THANKS to the folks on the DIY_EFI mailing list and Dr Bruce Plecan, who convinced me that my old CFI manifold may not be ready for scrap just yet. He's running just such a manifold on his system, which is described in the general background information below.
I picked up the Crossfire Injection manifold several years ago from an individual who had replaced it with a regular intake and carb. The 1227747 ECM and matching distributor (from a Chevy P/U -- 1991 TGMC 1500 8-350 2500 series) were mail-ordered from Peer's Used Auto Parts in WV (some more fine folks I found on the Internet). I'm sure it voids the warranty, but the first thing any engineer does is look inside to see what you've got to work with.
Next I visited a local junkyard to get a wiring harness. Unable to locate a suitable harness from a truck, I settled for one from a 1988 Oldsmobile. The Olds was a Sequential Port Injection system with MAF and DIS but the harness turned out to be remarkably similar. Practically all of the EFI portion of the harness was separated from other wires in the car. Several did return to the dash area, which I didn't care to disassemble. In retrospect, maybe I should have. You'll at least need the ALDL connector and the VSS unit from under the driver's side of the dash. Rotsa ruck, Raggy. I snipped the ALDL wires and got only the connector. If you skip getting the VSS here, you'll pay later.
With the harness back at home and a GM EFI manual in hand I traced the
wires and wired the system back
together. With a bit
of work I managed to spin the distributor with a drill and get comfortable
with the system. I had just about figured out how to
simulate a "run" on the bench when I decided it was time to go live.
Scantool MSPI Pro-Link $150 Linder Technical Services (317-487-1868 or http://www.lindertech.com) EPROM Programmer (11/12/01 update: XELTEK ROMMASTER/2 @ $179 died! The following is faster and cheaper anyway...) Intronics Pocket Programmer $150 UV Eraser Datarase II $39 General Device Instruments (916-393-1655 or http://www.generaldevice.com) bulk used EPROMS $50 (50 @ $1ea) EPROMS for the '7747 are 2732A. No AMD (too wide) and no raised windows. Astro Marketing (407-727-8817) (don't forget the age of these things...everything's got to die sometime) There's a special plastic carrier for the EPROMs: Robinson-Nugent PROM carriers part # PRC-246-E3 Used to hold the 24 pin PROMS. Min order need is 250. About 25 cents/part. A gracious list member (Thanks Mike!) organized a group buy. The "delco_edit" software aka "promedit" (by Wayne Blair) is a dandy piece of software for editing tables in a binary file. Editing the tables is much easier when you've got an appropriate configuration file (.ecu) for promedit. Here's how to use promedit and here's our work-in-progress .ecu file. NOTICE: There have been some incompatibility problems between the .ecu files and promedit. Until we can get that worked out, here's a zip file with promedit and the .ecu file I'm currently using. If you've got one of the older versions of promedit, here's an older version of the ecu file. There's also a more extensive one at the DIY_EFI website under GM systems but I make no guarantee about the compatibility thing again.