2020-B2-4

Author Topic: Looking to go EFI with your old school engine? You need to read this thread.  (Read 355 times)

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
Hey Guys,

I was having a conversation with a few different people this past week and I thought I would create this thread to share information on some clever ways I think we can get EFI on a budget with our cars.



Bolt-on GM TBI fuel injection...

For most of us 1st/2nd generation F-Body guys, our cars came with GM Rochester carburetors.  One way we can get EFI on budget is through use of a later model Rochester TBI.  These throttle body injection units came on late 80's GM vehicles all the way up to '95.  The most desirable of the bunch are probably the late 80's 454 truck throttle bodies.  Small block and big block versions can often be had very cheap and 80's-90's GM trucks are still plentiful in junkyards.  I've picked these up for $20-$30 many times.  This one, I had bored out and completely modified but this is just an example of what you can do with a GM TBI unit....
SPR Performance 454 TBI by Jonathon Randolph, on Flickr






Easy computer control...

Here is a place where we have a few options.  If you can find them, Pontiac guys can hunt down factory computer controlled '81 Pontiac 301 distributors (7-Pin HEI).  Likewise, Oldsmobile 403 guys can chase down 80's Olds 307 distributors for computer control.  I literally just found an Olds 307 distributor for $10 on eBay  :lol:.  Both of these distributors I mentioned drop right in your stock engine!  Another economical option we have is to remove your 4-pin HEI module and replace with a 7-PIN module and harness.  Cheap 7-PIN HEI modules go for $10 on Rockauto (AC Delco's are about $40) and outfits such as Performance Distributors (Davis Unified Ignition) can set you up with a computer control harness for about $25.  From there, on a vaccuum advance distributor, you would simply have to lock down the plates and removed the vacuum canister.  Below is an example of a 7-Pin '81 301 Pontiac distributor I'm currently rebuilding.  Again, 4-Pin HEI's can be modified for computer control for $100 give or take (depending on how you do it).
Untitled by Jonathon Randolph, on Flickr
Parts by Jonathon Randolph, on Flickr
Untitled by Jonathon Randolph, on Flickr



Factory oxygen sensor exhaust...
Some interesting GM pieces I've come across are 80's naturally Pontiac 301 and Olds 307 passenger side exhaust manifolds.  I have not verified fitment but these look like they could be useful for someone wanting to go EFI with a stock style exhaust.  The mid 80's Olds 307 and final Pontiac 301 exhaust manifolds have oxygen sensor bungs from the factory!  Here are some pictures I've found through some internet searching...
Naturally aspirated '81 Pontiac 301 exhaust manifold....
Untitled by Jonathon Randolph, on Flickr
Here's the back of an 80's Olds 307.  The manifold looks extremely similar to stock 403 exhaust manifolds that came on our cars but with an oxygen sensor bung already installed...
Untitled by Jonathon Randolph, on Flickr
SBC guys are lucky here.  LT1 exhaust manifolds flow very well from the factory and manifolds can often be had cheap.  With various people having done LT1 swaps, this looks like a great fit for EFI-ready exhaust in our cars as well...
Untitled by Jonathon Randolph, on Flickr



Oldsmobile 350/403 Trans Am guys, check this out!

Through surfing the internet, I just found that there is a factory aluminum 1970's port fuel injection intake manifold.  They are very rare but they came on late 70's Cadillac cars which were outfitted with 403's.  As an example, I just found a complete intake setup on eBay for $145+shipping.  I'm sure a parts car or engine can be found if searching various outlets such as Craigslist, Facebook, eBay, etc.  Late 70's Cadillacs are usually very cheap so you might be able to strike gold here.
Untitled by Jonathon Randolph, on Flickr
Untitled by Jonathon Randolph, on Flickr

Here is video of someone doing this setup with an Oldsmobile...
https://www.youtube.com/watch?v=4MZhTfQLTA4
 


In regards to converting to choosing a computer/fuel system, I would suggest looking into DIYautotune's step-by-step manual on how you can convert your car to EFI pretty cheap with the above components.  Their write-up great for seeing how to install and dyno differences compare between TBI fuel control, timing control added and then ultimately how one single engine performs with port injection and timing control...

https://www.diyautotune.com/support/tech/install/chevrolet-gm/carb-to-efi/
« Last Edit: March 27, 2020, 08:05:46 PM by jonathonar89 »

b_hill_86

  • Active Forum Member
  • *
  • Posts: 519
Good info. Thanks for taking the time to write it up.
-Brian-

1977 Trans Am 400 4 speed

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
Good info. Thanks for taking the time to write it up.

Thanks Brian! 

I think this is good information and I hope some take it as an eye opener.  Yea, you can go out and get FiTech or Holley Sniper for a similar price but the setups I mention here is with GM parts and can be done step-by-step.  I often see problems with the aftermarket TBI's online where people have to do some sort of modification, replace sensors, etc.  The only "aftermarket" thing I recommend here is getting a good computer to operate the system.

As often as EFI comes up these days, many mention MPG fuel economy when this or LS swap subjects come up.  While EFI is efficient, EFI vehicles and "LS" vehicles came with overdrive transmissions.  BOP automatic transmission guys can get very similar results by utilizing 200R4.  BOP manual guys can bolt up TKO and some other transmissions.

All this stuff is a good reminder that we don't need to swap to a newer engine to get similar technology/improvements from our old cars.  EFI and overdrive transmissions can be integrated into our old engines/cars.

FormTA

  • Oracle Forum Member
  • *
  • Posts: 3842
I appreciate the write up as well. I have always wanted to tbi my 301 on my Formula.

Just curious, why not use a factory ecm? Is it because you assume the engine is modified? I can't see a a stock 301 being to far off from say a 305 tbi truck or fbody engine.
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

Names, Luke. If I hear anyone telling me they're my father....

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
I appreciate the write up as well. I have always wanted to tbi my 301 on my Formula.

Just curious, why not use a factory ecm? Is it because you assume the engine is modified? I can't see a a stock 301 being to far off from say a 305 tbi truck or fbody engine.

You can surely try a stock computer! There are a few options...

Moates OBD 1 tuning....
http://support.moates.net/gm-86-95-obd1-guide-read-me/

Dynamic EFI (stand-alone GM computer tuning)...
http://www.dynamicefi.com/

pancho400cid

  • Oracle Forum Member
  • *
  • Posts: 1230
  • Viva los PONCHOS!
Following along with interest.  Thanks for the detailed info.

I hope to need it... one day.....
1978 Trans Am - Chesterfield Brown - current project
1978 Trans Am - Silver - SOLD!

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
Following along with interest.  Thanks for the detailed info.

I hope to need it... one day.....

Thanks, I have added some more stuff to my original post.  Any questions on this stuff is welcome!

Fbird

  • Active Forum Member
  • *
  • Posts: 153
one of the biggest issues with injecting an "old school" CAR is the FUEL DELIVERY system to the engine. There are many ways out there NOW ....just takes $$$. (i still prefer the IN TANK LS fuel pump bucket). The only other issue that comes up ....that WILL come up is the electrical system must be ROCK SOLID as computers do NOT like RF interference and the "old" 63 amp alternator just aint going to cut it.
67 Firebird
1980 Turbo TA (injected 400 now :) )

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
one of the biggest issues with injecting an "old school" CAR is the FUEL DELIVERY system to the engine. There are many ways out there NOW ....just takes $$$. (i still prefer the IN TANK LS fuel pump bucket). The only other issue that comes up ....that WILL come up is the electrical system must be ROCK SOLID as computers do NOT like RF interference and the "old" 63 amp alternator just aint going to cut it.

I'm not sure what you're trying to get at here but with our old engines, fuel or electrical systems become a limitation when you make changes.  Whether you're making more power with a carburetor, converting your stock engine to fuel injection or swapping to a newer engine, there are necessary upgrades either way you go.  If you're not wanting to make changes, then it's best to leave your engine alone and keep your car stock.

More specifically with the fuel system and in regard to my original post, I have provide a how-to link showing how to convert a 70's GM fuel system to support fuel injection.  Again, this can be done cheap with an inline pump and some fittings. 

In regards to the electrical system, 10si and 12si alternators are interchangeable on fitment.  Later style GM alternators are bolt-in.  The main thing is changing the serpentine pulley to a v-groove pulley and addressing the two wire plug.  A higher output alternator can be purchased as well. It's really not that bad.
-Without even talking about upgrading to a 12si, here is a drop-in 10si 100amp alternator from Powermaster ($128 on Summit)...
https://www.summitracing.com/parts/pwm-47127?utm_source=bing&utm_medium=cpc&utm_term=%2bpowermaster+%2b47127&utm_content=Powermaster&utm_campaign=Part+Number+Ad+Groups
-If you want to try a non name-brand 10si.  There are even 105 amp rated 10si alternators on eBay for $55.  I won't make claim to their ratings or quality but they are out there.
« Last Edit: March 29, 2020, 12:47:40 PM by jonathonar89 »

maxpowerta

  • Active Forum Member
  • *
  • Posts: 29
Here is my setup that I have been running for about 4 years, It features an aftermarket "speedmaster" port injection manifold, rails, and throttle body, refurbed junkyard ford red top injectors, 301 turbo computer controlled HEI distributor, and a factory GM 1227727 ECU from a 90's corvette (and other FWD applications) and of course a custom tune

1971 T/A 455 4spd, 1976 T/A 455 4spd, 1992 T/A Vert lb9 5spd, 1971 GTO 400 Auto

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
maxpowerta, this is an awesome setup you put together.  Very cool and thank you for sharing!

How have you approached tuning the GM computer?

I've been debating on using a GM computer or going the Megasquirt route.   

maxpowerta

  • Active Forum Member
  • *
  • Posts: 29
I bought the stuff to tune these computers years ago from moates.net so I could tune my 92 trans am, the ECM and all the sensors are straight from this era of GM cars. I use Tunerpro mostly and have a wideband o2 sensor on it so i can datalog and tune the system.
 
1971 T/A 455 4spd, 1976 T/A 455 4spd, 1992 T/A Vert lb9 5spd, 1971 GTO 400 Auto

firebirdparts

  • Jedi Council
  • Oracle Forum Member
  • *
  • Posts: 18710
That is interesting.  I had no idea anybody was using the old Electronic Spark Control distributors for that.
I want to be like Paul Kenny when I grow up
Joe Bays
1977 Y82 4-speed (red interior)
1978 Skybird 350
1978 Redbird 305
1979 Redbird 301 4-speed
1992 Lincoln Mark VII LSC/SE (red)
1970 Datsun Pickup
1953 Chevy pickup (converted 4x4)
1988 T-bird Turbo Coupe

maxpowerta

  • Active Forum Member
  • *
  • Posts: 29
The distributor was the easy part, under $100 from rock auto and virtually plug and play with the factory ecu.
1971 T/A 455 4spd, 1976 T/A 455 4spd, 1992 T/A Vert lb9 5spd, 1971 GTO 400 Auto

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
As this post coincides with budget, I picked up a 2nd-hand new Innovate LC-2 wideband (with gauge) and a used '81 301 exhaust manifold this week.
https://www.innovatemotorsports.com/products/db.php

Just an FYI for anyone, the Bosch wideband oxygen sensor that is supplied with most of today's aftermarket EFI kits thread right into the manifold. 

Untitled by Jonathon Randolph, on Flickr



2020-B1-8


Nexus

  • Oracle Forum Member
  • *
  • Posts: 1172
That's cool

I've considered often to maybe convert my non turbo 301 to turbo. That decision will have wait for a while though
Charlie

79 Esprit but like many, it will be a T/A clone
(19 years and counting but still have her)

jonathonar89

  • Oracle Forum Member
  • *
  • Posts: 2063
That's cool

I've considered often to maybe convert my non turbo 301 to turbo. That decision will have wait for a while though

I would just get some head work, cam and then do EFI if you want to do anything.....or just make sure everything is running good and convert to EFI.  Converting to turbo is a bit of a task.

Nexus

  • Oracle Forum Member
  • *
  • Posts: 1172
That's cool

I've considered often to maybe convert my non turbo 301 to turbo. That decision will have wait for a while though

I would just get some head work, cam and then do EFI if you want to do anything.....or just make sure everything is running good and convert to EFI.  Converting to turbo is a bit of a task.

that's true...I have looked into the late 80's TBI route as I though I had a free donor but my father gave away the parts and wiring harness out of that truck. Talk about cheap. I will go the carb route for the immediate future but I'm glad you started this thread, as I never considered using Caddy parts!!

thank you
Charlie

79 Esprit but like many, it will be a T/A clone
(19 years and counting but still have her)


 



2020-B1-4