[Gmecm] Looking for MPI/Conversion information for GM 454 CubicInch Engine

Thu Sep 15 13:38:36 UTC 2011

I find it interesting that I got Adrian?s response to my email before I got
my email.

The list server must be confused and or flakey this week.

A quick Google found some interesting solutions using factory stuff that
will get you MPI with some fabrication work.

If you keep your existing manifold, it will need to be drilled for the
injectors and / or have the injector bungs welded on. Then you?ll need to
get some type of throttle body to control the air flow and a place to mount
the TPS. This gentlemen found a cool solution in this 90? elbow adaptor to
go from a carburetor base to a throttle body. 

http://www.rowand.net/Shop/Tech/GMTPISwap.htm

If you want a factory manifold, complete with all the parts, you can search
for one of the 502 RAM JET manifolds. And from the quick search I did,
sounds like the manifold will outperform your heads, so better heads might
be in order as well.

Other things to grab in the junk yard would be an in-tank fuel pump with
harness, steel fuel lines, Heated O2 sensors, HEI distributor with ESC
module if necessary, ECU and as much harness as you can get.

Keep us posted, It sounds like fun.

From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] On Behalf
Of David Allen
Sent: Wednesday, September 14, 2011 12:54 PM
To: Adrian Flynn; gmecm at diy-efi.org
Subject: Re: [Gmecm] Looking for MPI/Conversion information for GM 454
CubicInch Engine

Adrian, glad you're considering an EFI retrofit!

One major thing to watch for, is buying all parts from the same donor
vehicle. I've run into issues with imcompatible parts, missing small items,
and various other 'gotcha' issues when the donor vehicle is not available,
or parts have been ordered from here and there. 

Have you considered a TBI?  It is mosty the same, electronically; but the
unit is simpler to install. I know for fact there are 454 TBI manifolds, but
I haven't seen a 454 MPFI manifold. 

You could easily bolt on a TBI manifold and wire everything up and it would
run without any real headaches.

If you want multipoint injectors "just beacause" (which is fine here!), the
electrical install will be basically the same; but you may have to build a
fuel rail, drill the manifold, and of course the tune will be a completely
custom job.

Sincerely

David

----- Original Message ----- 

From: Adrian Flynn <mailto:adrianjamesflynn at gmail.com>  

To: Gmecm at diy-efi.org 

Sent: Tuesday, September 13, 2011 2:27 PM

Subject: [Gmecm] Looking for MPI/Conversion information for GM 454 CubicInch
Engine

September 13, 2011

Hello to everyone,

I have been setting in the background reading the posts and trying to make
sense out of them.

I am about to get my feet wet (as it were) with my 1973 3/4 ton Suburban.
4X2

What I want to do is add Multi port Injection in place of the
Carter/Edelbrock Carburetor that is currently powering it.

I would like some pointers in the right direction as to what I will need to
do to accomplish this.

What I would like to do is acquire a complete GM system from a junkyard 454
(Yeah I know Headaches),

My main reason for doing this is that I am living on a Disability income and
don't really have the coins to 

buy a NEW unit.

Electronics was my lively hood for over 35 years as a repairman of TV's,
Stereos, Microwaves ETC;

so computers and such do not bother me and I have the tools for servicing
them.

Only thing I do not have is Scan Tools for Automotive Computers, OBD_I & II
etc.

I know this is reinventing the wheel but I hope to be able to get the
information I need to do this., and what pitfalls to avoid

The Suburban is a factory 454 with the turbo 400 Transmission, it is
equipped with long tube headers, dual 2 1/2 inch cherry bomb exhaust.

I will be upgrading the Transmission to a 700R or 4L60 in about a year or
so.

The Suburban does not have a Cat on it (Missing when I bought it in AZ) but
don't mind putting one on if need be for best usage.

My goal is best fuel mileage possible, with maximum low end torque.

I WILL NOT BE RACING IT!

I may be towing with it from time to time a trailer that grosses out at
12,000 lbs.

I use to have a 25' Sports Coach on a GM Chassis with the 454 and I averaged
15 MPG when I was not towing a Ford E150 behind it, with the E150 I averaged
10 MPG.

OK, I probably have bored you enough but I like to try to fill in the basics
of what I have and plan to do when asking questions like this.

I thank you for your time.

Adrian Flynn KF7DYU

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