Analog Cadillac/Bendix to'730

[Swayze]

My project is a '77 350 caddy(olds). I'm not sure about the differences between the 500ci and 350 cid caddy fuel injection, but in my book the '730 route is definitely the way to go. some sites to visit in addition to the archives and programming 101;
http://www.tunercat.com/tnr_desc/do_tc.html

http://www.gnttype.org/techarea/fuelsystem/injflow.html
there are also several injector specs files at the ftp site
http://www.jimsperformance.com/
source of info on TPI that is a good start (also universal TPS)
http://www.lindertech.com/
the Injector Guru.. has a good .pdf document on injectors

there are a whole lot more places to see just read,read,read.
..........
Subject: Analog Cadillac/Bendix to'730
.......

..........
> My project is to convert a 500ci Cadillac with a bendix analog
> controller to something more flexible, say a '730 or similar. I don't
> have a strong background in digital electronics and I have a couple ..................
> Questions:
> 
> 1. The Cadillac injectors are low impedance, are they compatible will
> the 730's driver?
 
   1. I sent the injectors from a 350 (ND1181281(531C)) to the injector guru to be reconditioned. I will be using a '727(underhood '730). there is an injector driver circuit at the ftp site I am probably going to need to use(haven't gotten that far yet--but it keeps me from machine work on the manifold and fuel rail)

> 
> 2. If the stock injectors won't work, how would I size replacements? the
> engine is rated at 210hp at 3600rpm. would it be safe to assume that if a
> 350ci Chev used 24lb/hr injectors that an engine 50% bigger would use
> 36lb/hr injectors?
 
     2.see Handycalcs.zip at the ftp site or 'Bowling' calculator..if you need more detail see Al Grippo(sp.) formulas from DIY_EFI.I don't have the book mark for it .the injectors I have are rated somewhere between 36 and 47#/hr (I have yet to find specs on the specific injector)

> 
> 3. The Bendix throttle body doesn't have an IAC, it has a fast idle
> valve that is electrically heated and allows an air bleed till warmed
> up. Could one substitute a standard GM IAC in place of this?

    3. I am modifying the Bendix TB on my project to use a '91 vette IAC (this involves turning special bushings--it helps to have a machinist friend) and picked up a universal TPS from JimsPerformance (again more machine work) . there are a couple of special little plates that have to be fabbed also. from what I've seen of Bob's 403 the TPI TB is easier if you don't have access to machinist friends.near as I can guess the bendix TB is the functional equivalent of a 557cfm carb(rough numbers) it has 56mm bores.

> 
> 4. I picked-up a junkyard '730 and a few others '748 etc, the '730 has
> the eprom  on a large carrier with some other chips. The '748 just has
> the eprom alone, Are these other chips part of the limp home settings?
> are they compatible with a larger (Cadillac) engine?

    4. the '730 '747 ECM information is all over the archives. the '730('727) aujp.bin,.asm,.ecu files are at the ftp site in several places. suggest you download a copy of WINBIN or PROMEDIT and see whats really involved 'tuning' wise after reading programming 101. haven't figured out what to do about limp home mode though(is it really necessary?)
> 
> 5. Could someone tell me the difference between Memcal, calpak, limp
> home resistor packs?

   5. .(basically the smarts of the ECM)
this is a question for Ludis or Grumpy
search the archives.

> 
> 6. Are there companies/ individuals who will custom  burn eproms based
> on : engine size, intended use, etc? Is this something that would be
> best done by myself?

        6. my take on custom burning is find an emulator (hopefully soon to be a GMECM group buy) to do all the tuning and then get a chip burned.( or boot the car when you get ready to drive it(((open and close all the windows first?))))

> Thanx,
> Russ Harms
> 
I tried to track down the original circuitry. this is about as far as I got on the analog FI;
http://patent.womplex.ibm.com/details?&pn10=US03816717
good luck
byE
Mike
Swayze
mswayze at truswood.com
kswayze at bellsouth.net


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