Throttle Body Injector (TBI) for 3.5 V8 - Defender Source
Defender Source  

Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions


Reply
 
Thread Tools
  #1  
Old January 5th, 2006, 02:03 AM
gregorw47
Status: Offline
Gregor
Member
 
Join Date: Jan 2006
Location: University City, Sharajhah, U.A.E.
Posts: 4
Post Throttle Body Injector (TBI) for 3.5 V8

Information needed to convert my old 3.5 EFI to a TBI system. From what I've read, this system appears to be an ideal solution, rather than reconditioning the wiring and injectors in my 1988 LR 90. Where can I get (cheap, if possible) a carb manifold and the correct TBI system for this car to convert it? Do I need a specific manifold for this? What year Buick V8 am I looking for here? Experiences with this kind of set up?
Thanks for the info,
Gregor Weiss
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old January 5th, 2006, 02:26 AM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
Well, I don't think that there were any factory TBI systems for the 3.5. You could probably use the Edelbrock manifold with an adapter to fit a GM TBI.

It would be a definite downgrade though in efficiency, multiport systems like you have now are very much superior to a TBI system. You have the 'flapper' system on that year, correct? Maybe upgrade to the Hot-Wire?

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #3  
Old January 5th, 2006, 10:03 AM
Roadsiderob's Avatar
Roadsiderob
Status: Offline
Robert Dassler
1994 D90
D-90 Source Vendor
 
Join Date: Apr 2004
Location: Albuquerque, NM, USA
Posts: 994
There is a new Edelbrock manifold on Ebay right now.

Follow-up Post:

Here's the link
http://cgi.ebay.com/ebaymotors/Land-...spagenameZWDVW
__________________
Rob Dassler
SWR Automotive
505-872-7818 (shop)
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old January 5th, 2006, 03:09 PM
gregorw47
Status: Offline
Gregor
Member
 
Join Date: Jan 2006
Location: University City, Sharajhah, U.A.E.
Posts: 4
Post Flapper; hotwire?

Thanks for the quick info. I'm not all that familiar with TBI systems, but I'd heard that it was only a slight downgrade in performance and that the system was tuneable, for highway and off-road power. I like the idea of simplicty and dumping the complicated multiport system.
I don't know if I have a flapper system; the system was probably put on later, I think the car started out carbureted. What is a hotwire system?
Thanks again,
Gregor


[QUOTE=Hans]Well, I don't think that there were any factory TBI systems for the 3.5. You could probably use the Edelbrock manifold with an adapter to fit a GM TBI.

It would be a definite downgrade though in efficiency, multiport systems like you have now are very much superior to a TBI system. You have the 'flapper' system on that year, correct? Maybe upgrade to the Hot-Wire?

-Hans
Reply With Quote
  #5  
Old January 5th, 2006, 05:17 PM
jaherring's Avatar
jaherring
Status: Offline
Jason Herring
94 D90 ST #1253
Member
 
Join Date: May 2004
Location: San Pedro, CA, USA
Posts: 582
I used a Holley Pro-Jection system in the past and it worked pretty good - I retrofitted a '79 Jeep J-10 360V8 and wow, what a difference!

The upgrade will be so pleasant over and above what you experience with your carb you may not care to know that the multiport setup is another step up However, if you are interested, I think you could find a 3.9L setup in a junk yard that you could bolt-in cheaper than a new Holley (or equivalent) unit. It's a little more work, but probably cheaper (if you find a junkyard with a Disco or Range Rover 3.9 or early 4.0?). Anyway, a pre-OBD-II setup is far easier than a later model setup.

Of course, some places will charge you gold for that setup (usually an LR-specific yard) but if you find a general yard with a wrecked LR you'll make out financially and performance-wise.

Aside from the intake/TB unit you'll need the computer and the other sensors that go with it - O2, MAF, VSS (if equipped)... look at a factory wiring diagram for the year vehicle you pull the injection from.

But, you can avoid all that and just buy aftermarket, too..
Reply With Quote
  #6  
Old January 5th, 2006, 09:22 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
The question I really have though is, which system do you have? Once we narrow down what you have, we can help figure out your best options. This link shows the two different types of Mass-Air sensors for the two different EFI systems. http://www.v8engines.com/carbs-3.htm

You might be able to get a wire harness from e-bay or other source for fairly cheap, send the existing injectors out for cleaning and balancing, and be finished up real quick. What problems are you having with the existing system?

Another thing is, how handy are you with doing wiring and tuning? If you're good with electronics and doing your own work, there is also the MegaSquirt system. It will wire into the existing system, eliminate the Mass Air sensor, and give you full datalogging and tuning with a laptop.

Heck, you could also throw the Edelbrock manifold on there with a 4-barrel carb, but your milage will probably go down.

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #7  
Old January 8th, 2006, 05:24 AM
gregorw47
Status: Offline
Gregor
Member
 
Join Date: Jan 2006
Location: University City, Sharajhah, U.A.E.
Posts: 4
Thanks for all the helpful information so far on this. Hans, its a flapper, according to the website you sent.
I've heard of the Megasquirt, and I'm pretty good with mechanics and electrical wiring. It looked pretty complicated though. Anyone have experiences with this?
In the end, I want something that I have some confidence in troubleshooting. I drive into the outback and around the region here in the U.A.E., and I don't want to get stuck somewhere with a bum EFI system. Eight injectors and all the wiring (and some of it's pretty old), plus the plumbing etc. makes for a real diagnostic nightmare when one is far from home, so the relative simplicty of the TBI sounded pretty good, but with the expense of conversion, weighing some other options is helpful.
Thanks for all the helpful comments,
Gregor Weiss
Reply With Quote
  #8  
Old January 8th, 2006, 12:22 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
Honestly, if reliability and simplicity are the desired traits, why not just toss a carburetor on there? It removes the entire issue of the wiring mess, and they have always been very reliable. It would only take an afternoon or less to install it, and if you use the Edelbrock manifold and a good 500cfm carburetor it should also increase power for you. You could use the same manifold to eventually put the TBI system on. The only drawback I would see in your case would be possible increased fuel consumption, but depending on the condition of your current system it may also be an improvement in that regard too.

The MegaSquirt has been working well on my Jeep, but it does take a while to get all the details worked out and the tuning finished. In theory, even the computer is repairable in the field, but I wouldn't go so far to guarantee it won't eventually leave you stuck in the middle of nowheere.

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #9  
Old January 8th, 2006, 12:35 PM
Doug's Avatar
Doug
Status: Offline
Doug Walker
TVR5L-powered NAS D-110
Member
 
Join Date: Oct 2003
Location: Los Angeles, CA, USA
Posts: 880
I'd go carburation, or 14CUX hot wire with lots of spares. I carry a box with a spare set of relays, MAF, even ECU but they hardly ever fail. I'd worry more over the fuel pump which is known to go bad. Also a spare ignition switch.

Doug W.
Reply With Quote
  #10  
Old January 8th, 2006, 12:55 PM
Roadsiderob's Avatar
Roadsiderob
Status: Offline
Robert Dassler
1994 D90
D-90 Source Vendor
 
Join Date: Apr 2004
Location: Albuquerque, NM, USA
Posts: 994
I've converted a couple of grey market classics with the factory dual carbs to the edelbrock 4bbl manifold. For ultimate simplicity it works well. I would use a Holley 390CFM 4BBL. I have had the best results with those on the 3.5l motor. 500CFM is a bit big IMHO.
__________________
Rob Dassler
SWR Automotive
505-872-7818 (shop)
Reply With Quote
Reply

Lower Navigation
Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions

Tags
body, v8

Thread Tools

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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pinging under full throttle... Doug Defender Technical Discussions 10 November 29th, 2005 11:02 AM
lifting the body (not plastic surgery :-) cbass Defender Technical Discussions 11 April 25th, 2005 12:14 PM
Throttle body size on a Thor manifold? Hans Defender Technical Discussions 1 March 10th, 2005 10:10 PM
body work on aluminum mattdh Defender Technical Discussions 11 July 4th, 2004 02:47 PM
Hand Throttle sherpamike Defender Technical Discussions 19 April 3rd, 2004 12:23 AM


All times are GMT -5. The time now is 09:31 AM.


Copyright