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40K views 104 replies 17 participants last post by  rdohm 
#1 · (Edited)
I recently bought a '75 Caddy 500 and I am looking for a good way to put an updated FI system on it. Is there a good company that does it or if a company makes an updaed manifold to fit new injectors....Please Help


Thank you in Advance


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#2 ·
Well, if you're technically inclined, join this group: http://autos.groups.yahoo.com/group/megasquirt/
It's a totally homebuilt FI system. You can buy a PC board and parts kit from them if you want, or not. All the information to build the system is there and free.
If you really want to push your technical skills, you can go here:
http://autos.groups.yahoo.com/group/megaspark/
Electronically controlled ignition...
I used to belong to these groups, and probably will join them again, as I want to build a multi port FI for the 368 Hearse I'm buying.

The megasquirt is versatile enough that there is even one guy (IRC) that has on on a motorcycle... So there is a project I could use too...

Good Luck
 
#3 ·
If you know how to do the rest of the system, great. The options for manifolds would be:

-Stock manifold drilled for injector bungs (cheapest but a PITA to drill properly I'd imagine)
-Stock FI manifold, 1976 only and IIRC maybe 1% of cars had that option so it's RARE.
-Bulldog cast aluminum single plane manifold, which has places to drill for injector bungs easily.
-Boogieman from Potter, which is a good manifold but not sure if it will clear a stock hood if that's what you're working with.

Wouldn't bother with the Edelbrock 2115 especially since you're doing FI.
 
#4 ·
Options for manifolds also include 425 F.I. manifolds which are the same except for some EGR differences and will work on the 500. They are not too difficult to find if you know where to look and are not in a hurry. Someone made an adaptor to use a Fode 460 manifold on the 500. IIRC they made a port injected 460 for trucks. Maybe there's one waiting in the truck boneyard near you.
 
#5 ·
I knew I was forgetting something. The adapter plates for the 460 work, in fact a friend of mine is designing a cross ram FI manifold for the BBF in one of his mech. engineering classes that I could run on a 500 with those plates.

I forgot about the 425 FI manifolds but they're pretty dang rare too.
 
#6 ·
The stock F/I intakes are rare.. But Al at MTS had some on ebay and did not sell them.. So if you give him a call I'm sure he's got some with throttle body.
There are many aftermarket computers that will run your car just fine.. from a built it yourself for a few hundred... to $1000 to $3000 ready to go systems.
 
#11 ·
Yeah, but where else can you have a laptop sitting on the seat beside you as you adjust your fuel curve, injector timing, and everything else associated with it...
Then kick in the megaspark and adjust everything having to do with spark...

Yeah, it does look intimidating tho, prolly why I haven't started on it yet... :)
 
#14 ·
Haha dave until I got to the end of the post I thought you were going for LPG injection...the carb is always good, but I'm ready for something new. Aside from having no flat spots, etc like a carb and better fuel economy, I think I will have a serial cable coming into the cabin permanitly, and then just buy an old laptop, re-format it and put nothing but the Megasquirt software on there, and make that it's dedicated job.
 
#24 ·
Yeah you really should, that's a great price for any good 500, but then throw in the EFI option and it's just too good to miss! If it weren't so far away I would go grab it myself and rob it of the manifold, fuel rail, gas tank intake parts, etc and keep the rest for parts or sell it, something like that.
 
#25 ·
davesdeville said:
After some searching I guess it was offered those years. Through all the cars I've looked at I haven't seen a single FI 75, much less 74. So I will stick to my statement about them being rare.
Oh, they are rare! I've never seen a '74 with EFI, but I've seen some '75's. The '76s seem to be the most plentiful, and they are out there if you look hard enough! :bonkers:
 
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