Aftermarket fuel injection?

[TJH clc#20664]

Hi All!

Here in the upper Midwest USA where our cars are asleep for the long road salt season, I have begun thinking of what I am going to do to my 73 eldo convertible before spring.  One of the many projects on the to do list has been to rebuild the engine and maybe add a few fun / practical things to it.   One of the things I have become a BIG fan of is fuel injection.  Has anyone used or have an opinion on any of the aftermarket kits that are available for the 500?  I have seen kits to upgrade the OE FI system which mine does not have but I do know where I may be able to get a ’76 deville for parts.  I have also found companies that will machine the manifolds for new injectors to allow you to use many of the computers and stuff that are available these days for other performance applications.  Holly makes a bolt on throttle body system I think called ‘projection’  that looks interesting and I have talked to some people that have used it and like it.  If you get the basic open loop system its not to expensive but by the time you upgrade to the closed loop version it gets as expensive as the multi port systems.  The system that looks the best to me is from http://www.affordable-fuel-injection.com. TARGET=_blank>www.affordable-fuel-injection.com.   It looks to be a custom / rebuilt system based on the late 80’s and early 90’s  GM TBI system.   I have owned several cars with this system and never had any problems other than fuel pumps so I know its reliable and parts are easy to come by.  It includes:  Rebuilt HEI ESC distributor, rebuilt TBI unit, Rebuilt ECM, complete wiring harness, AFI calibrated chip, Adapter plates, gaskets, fuel pump, fuel pump relay, and sensors.  The over 360 cube kit is $1395 according to their website.

What do you guys (and gals) think?

Thanks!

TJ H
CLC #20664
73 Eldorado Convertible
Mpls/ St Paul  MN  USA

[George Woodford clc21025]

I would recommend you contact one of the CLC Tech Reps on EFI used on mid to late seventies Cadillacs.  I am aware of one person who installed an aftermarket EFI system on a 1976 Eldorado.  My understanding for this project was that the engine was rebuilt with higher performance specifications, which the OEM computer could not compensate for the different parameters.  Apparently, it was not possible to modify the OEM computer to work properly with the rebuilt engine.

[Andrew 10642]

I would recommend going with a much more modern FI setup, as putting a 75-79 series EFI setup will not be considered any less of a modification, and that system, which was based on the Bosch D-jet technology, was really out of date by the time it was introduced in 1975 at GM.  I would try to keep it as simple as possible, and use a system wqhich is easily serviced.  The D-jet is not.  Find out why by googling it.  Mercedes, Volvo, Porsche and Volkswagen had all given up on that version of FI by 1976.

Had a 79 Fleetwood with EFI, and still have a 73 Volvo with D-jet.  I would never rip out the system, but I would never convert over to it, either.  Try the modified board forum, also!

http://www.modifiedcadillac.org/index.htm TARGET=_blank>http://www.modifiedcadillac.org/index.htm

[Michael Stamps 19507]

Im going to ask you a question before responding.  What do you want to gain from a FI set up?

Stampie

[Ed Mobley - CLC 19300]

My main concern would be the reliability compared to a well maintained carburetor and points setup. Sure, it might run slightly better, but you run the risk of the thing just quitting.  Dont mean to rain on your parade, but Im somewhat of a Luddite after a bad experience with an electronic ignition upgrade on my 60 Caddy.

Regards,

Ed

[TJ H clc#20664]

Thanks for the replies!   What I hope to gain is drivability and reliability and maybe just a touch more performance.  I have not been stranded with the quadrajet in the last nine years but it seems that there is always some little thing wrong with it like a bit of a hesitation on tip in and I have never got the choke to have good drivability from a cold start.  The carb is due for a rebuild again anyway and this time I think I have the time and money to do the engine too.   I never minded carbs before but in the last few years I have converted my fleet to EFI systems (including a new 05 Hemi Magnum (why cant GM build a fun car like this!)) and have become a big fan of turning the key and going if I want too.  I also would let my friends drive the car but starting (especially hot) can be very temperamental.  The engine is just original and very tired.  I know it has cracks in the plastic timing gear and it has started weeping everything from everywhere.  I have read enough about the original 70’s EFI systems to know they seem to be more trouble than the carbs.  The system I found online I liked is based on GM OBD1 TBI systems.  From what I have seen and experienced with other vehicles with these systems these are very simple and reliable, also very easy to come by parts and many people that know how to work on them.  Sadly you can’t say that for the old quadrajets these days.  The guy that is going to rebuild the engine for me is also good with carbs so I can always have him rebuilt it along with the motor but I keep thinking of my 87 V20 truck and my 93 Roadmaster both over 200K on most of the original parts.  The car is rust free from Texas but has been hit pretty hard on the drivers side and in the front at some point in its life and because of that an appraiser told me that it would never be a #1 condition car without some serious work so keeping things original is far less important to me than having a fun reliable car to drive.

TJ Hopland
CLC # 20664
73 Eldo Convertible
Mpls / St Paul, MN USA

[denise 20352]

> Sure, it might run slightly better, but you run the risk of the thing just quitting.

   That is quite true.  Our 92 truck has died three times without warning, twice for ignition module and once for an electric fuel pump failure.  They dont blow any codes or start running rough, they just die.

-d

[Ed Mobley - CLC 19300]

As Denise points out, the modern systems will at least tell you whats going wrong.  They can even point out the bad component (oxy sensor, airflow sensor, temp sensor, etc.).