Converting from FI to SU

[pbatura]

I've made the decision to convert my son's '76 FI to carbs, and need to get hold of good resources to do it right.

I've read a number of posts, and believe I've got some great starting info, but need manuals on proper installation and setup for a '71 SU setup.

Thanks in advance for direction.

[e_racer1999]

if you weren't in TX i'd swap you my entire 72 SU setup for your entire FI setup

[Zedrally]

Ah, you beat me to it. Realisticaly Oz is too,too far even for post...

Pbatura, why do you want to do this, FI beats SU's anyday?

[beandip]

I've made the decision to convert my son's '76 FI to carbs, and need to get hold of good resources to do it right.

I've read a number of posts, and believe I've got some great starting info, but need manuals on proper installation and setup for a '71 SU setup.

Thanks in advance for direction.

:hurt: First off I am a SU guy, but why are you wanting to dump the injection in favor of SUs ? I am running SUs on my '82ZX engine that is in my 240. The engine runs strong. What is needed is a intake manifold from a '70--'73Z , You need a set of SUs either 4 or 3 screws , and the linkage as well as the fuel rail. The 280 fuel pump delivers WAY to much pressure about 35 psi . I am running a RX-7 pump that I took from a '79 carburated RX. Delivers 5 psi. $15.00 at the u pull it . I recommend that you also run the early air cleaner as it has tuned velocity stacks mounted in the air box for better performance. After some testing I found the 54 needles that were for the L24 are a good choice for the SUs , I tried several needles and these seem to be the best. At least in my Z. Gary:knockedou

[Bruce Palmer]

... sold by ZTherapy would be a great tool to have on hand. It will give you many opportunities to view what you are shooting for after the install is complete.

[Arne]

Been there, done that, wrote a tech article. While my situation was not exactly the same as yours, this should give you an idea of the basics, and the video from ZTherapy will give you specific info on setting them up and tuning them.

The tech article I wrote: Fuel injection to SU carb swap

Link to ZTherapy - click the Videos link on the left: ZTherapy.com

[e_racer1999]

SU tuning video sold by ZTherapy would be a great tool to have on hand. It will give you many opportunities to view what you are shooting for after the install is complete.

listen to this man! just because he works for ZT doesn't mean he's trying to sell you something just to make $$! those videos are a MUST for someone who wants to learn how to tune SUs

[FairladyZS30]

if you weren't in TX i'd swap you my entire 72 SU setup for your entire FI setup

I still have my entire FI for my 76 ill trade ya' :laugh:

[e_racer1999]

don't tempt me....

[FairladyZS30]

c'mon.....you know you want it =]

[pbatura]

Wow, great comments!

First, why. This has been my first Z-car project. My other projects have been Mustangs ('65 & '66 fastback, '82 GT) a '72 Comet GT (Mercury version of Maverick Grabber) and various other Blue-Oval vehicles as daily drivers.

Bottom line: the FI has been a pain to work with. Too much time chasing down wiring. All tests indicated bad ECU so I got a replacement (used) and it was no good. Checked eveything, I mean everything, and I've decided to go back to what I know - carbs.

With a nod to the EFI guys, my son is heading to college and I need to minimize potential problems with his car and have greater reliability.

I've got a complete (well, nearly - missing fuel rails and balance tube linkage and still need them) assembly from a '71 inbound. Condition looks good, but will know when it arrives. Still need to get fuel pump - great advice on the RX-7 pump. What year am I looking for?

Also, since the fuel pump is powered through a relay, it seems I would need to modify the wiring accordingly. Thoughts on this would be appreciated.

BTW - I wish I would have posted this before I bought the setup, as it sounds like I could have saved some cash. Now I have a complete FI system available - from wiring harness to filter housing and everything in between.

Thaks for the help. I'm off to buy the video...

Best regards,

Peter

[Mat M]

You may want to do a search for electric fuel pump. It was Marty Rogan who helped me with mine:

http://www.classiczcars.com/forums/showthread.php?t=24026&highlight=electric+fuel+pump

Specifically this post:

http://www.classiczcars.com/forums/showpost.php?p=197940&postcount=10