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EFI to Carb swap ? - 1976 Eldorado

23K views 29 replies 11 participants last post by  dennisspeaks1 
#1 ·
I have a 1976 Eldordo with factory EFI. Am curious to know what the expert opinions may be on if the EFI should be swapped for a carburator? How reliable are the old EFI's and how available are EFI parts etc?
 
#4 ·
--------------------------
if the EFI should be swapped for a carburator
the original EFI system was SO bad - they made a carb-swap kit -
and the vast majority did the swap -

if you LOVE to tinker - and REALLY ENJOY being frustrated -
stay with the EFI -

if - on the other hand - you would rather go for a nice - relaxing cruise -
put the carb on it -
 
#7 ·
My opinion is the carb cars never even came close to running as well as the injected Cadillac 500 or 425. They do take knowledge to keep running though.

I would sooner switch to a more modern injection like a Megasquirt than put a toilet bowl on top of the intake manifold.

If you are anywhere near Toms River NJ I'd be glad to take all those awful injection parts off your hands in exchange for installing the carby/intake/misc stuff.
 
#8 ·
The main problem with those old computers are they are old.. They say the parts are hard to come by, but I have a bunch of them.. There is a member of this board , Bruce Roe, that fixes the computers and some mods to keep them running with less problems... If I had your car I would just keep some spare parts on hand, like a spare computer and a few temp sensors.. I would take out the low pressure fuel pump in the tank and put in a high pressure pump.. That way you can take off the high pressure on the frame and just use one pump... And do Bruce's extra relay mod to run the pump to help save the computer...The only part that is hard to find is the fast idle heater valve... I had a lot of them , but there all gone now...
 
#9 ·
Good info. The 500 C.I. fuel computer is not as easy as the 350 or 425 to come by in my experience. Agree on the pump. The other liability is the fuel lines.

I'm fairly sure someone could adapt an external fast idle valve like some of the Euro Bosch EFI cars of the era used. Probably been done already.
 
#10 ·
Apeman... I have a used 500 computer that has been gone over by Bruce that looks the day it was made... Somebody will need it one of these days... I have a fuel injection set-up on a 472 run by a haltech... I made a fast idle replacement set-up... It is a solenoid valve that is closed by a timer circuit board and the haltech at a temp.. It closes when it reaches 150 F or if it is already warm it fast idles for 60 seconds...
 
#18 ·
Hi, here in Brazil I have a 76 Eldorado EFI and tired of trying to fix the fuel injection source. I installed the FuelTech, which is a programmable fuel injection and had no more problems. All original parts have been exploited and appearance of the engine remained the same. For the 500 engine, the fuel injection models used are the FT 300, FT350 and FT400
Not cheap, but solved my problems.
Manufacturer's website http://www.fueltechems.com/home.html
 
#19 ·
Hi, here in Brazil I have a 76 Eldorado EFI and tired of trying to fix the fuel injection source. I installed the FuelTech, which is a programmable fuel injection and had no more problems. All original parts have been exploited and appearance of the engine remained the same. For the 500 engine, the fuel injection models used are the FT 300, FT350 and FT400. Not cheap, but solved my problems.
Manufacturer's website http://www.fueltechems.com/home.html
Did you use the same injectors at the same pressure? Still bank injection, or change to sequential? The same ignition, or an ECU programmed advance? Did you change the temperature sensors? How long did it take to get everything tuned up? Did you use an OX sensor? Did you change the idle air motor? Is your old ECU available for another Cad owner? Bruce Roe
 
#26 ·
I think the carb should bolt to the EFI intake manifold, but you'd need to install a fuel pump from a carbureted engine, since the in tank pump would have too much pressure. I'm not sure if the EFI distributor would work, but a swap to one from a carb'd engine is an easy fix.
 
#29 ·
If that car has been sitting for years you are going tohave to drop the gas tank and clean it out. Take the pump out and replace it with a Walbro 255 pump for a 80's gm car like a grand national. That can be made to fit. Then just take the frame rail high pressure pump right off and plum the fuel line straight through. Cap off the power line to it.Do Bruce's mod the the tank pump.Change the filter thats on the drivers side on the front of the motor.
 
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