Boneyard Injection? - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 04-11-2003, 10:12 PM
Posts: n/a
Boneyard Injection?

I know that I have read it on here before, but when I search for it, I cannot find what I'm lookin for. I am wondering just what parts from the boneyard a guy would need to have poor man's fuel injection on a 258. I think I heard 305 chevy throttle body, but what about computers? I have emissions tests to get around here in Ohio, and I am tired of the stock Carter BBD. Bad gas mileage, tough hot starting, mostly the full deal on mine. I hate taking my stuff for someone else to work on [img]images/graemlins/bs.gif[/img], and that's exactly what has to happen when the [img]images/graemlins/AR15firing.gif[/img] carb starts acting up. Would a 4.3L throttle body be a better fit for a 93K mile stock 4.2? If this ain't too hard I think I'll try it. If somebody could explain this I'd be forever grateful... [img]images/graemlins/40BEER.gif[/img]

Green Grass and High Tides Forever [img]images/graemlins/RockOn.gif[/img] [img]images/graemlins/scs.gif[/img] [img]images/graemlins/givemebeer.gif[/img]
Sponsored Links
post #2 of (permalink) Old 04-11-2003, 10:59 PM
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Boneyard Injection?

You'd better research the emissions testing in your jurisdiction before you go any further. Is is a sniff test or does it include a visual requiring all oem equipment to be in place? You may pass the sniff test, but the second one you are out of luck unless you can fool them, or buy an approved system like Howell's.

For GM tbi I see three options:

1)Buy a complete system, Howell, Turbo City, Affordable Fuel Injection, etc. Install and turnkey.

But you want junkyard right?

2) a) Install a complete 4.3L TBI system by extracting every part and whole harness from a donor vehicle. I know a guy that did it, and he says it works great. See this source for some info:

Do it yourself page

For best results, you need to modify the chip. These systems all estimate air flow by a method known as speed density, which relies on accurate tables of volumetric efficiency of an engine at various rpms and MAPs (manifold absolute pressures). A 258 is very different from a 4.3 in torque curve and would be probably lean at peak torque rpm and rich at a higher rpm if you used an unmodified 4.3 chip.

b)Buy the chip, harness and adapter from Howell and use a junkyard ECU, tbi and whatever else you care to scrounge.

c) Burn your own chip. See the DIY EFI group.

3) Go full experimental mode and use a 4.3, 305 or 350 TBI (all the same size venturi, only the injectors vary in fuel delivery capacity, measured in lbs/hr) and a universal controller like Megasquirt

Megasquirt frequently asked questions page

The only way you will pass testing with the megasquirt is if they only check for proper emissions, and even that is bound to be a challenge, although it has been done.

I live in an area of Canada where there are no emissions testing and I am using Megasquirt on my 258. I've very happy with the results and the fun of the ongoing tuning. Do a search here for Megasquirt and there should be a long thread where I have some info and pictures. I think it dates back to January. Mike, who frequents this board is in the midst of getting his squirted 258 running.

I'd also like to see someone try a 4.0L intake manifold and injectors and fire them with the megasquirt. It should work as well, although the squirts will not be sequential. This will make little difference except at idle. Lots of multiport engines run very well on batch fired injectors and idle just fine. Emissions might be worse though. I am told no difference at speed. If I had another engine, I'd try it myself. On the other hand, the tbi system is working well and delivers superior horsepower to the carb, so I have to wonder, why bother, except to satisfy my curiosity.

Tom, who frequents this board, is putting together a boneyard based GM tbi system, except he has a spare Howell chip to run in it.
TiminMb is offline  
post #3 of (permalink) Old 04-14-2003, 12:08 AM
Join Date: Jul 2002
Posts: 111
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Boneyard Injection?

The pictures in tha article you link to do not show, any ideal why, anybody else have this problem???...09 [img]images/graemlins/confused.gif[/img]
Loafer409 is offline  
Sponsored Links
post #4 of (permalink) Old 04-14-2003, 09:44 AM
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Boneyard Injection?

Pictures? There's very few pictures. The do it yourself link has none, and the megasquirt has few. But I did see some. Mostly a text writeup.
TiminMb is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome