FI to SU's question

[zman525]

when i swap out my EFI for SU's im goin to need a mechanical fuel pump right? would i need the gas tank aswell or would a 280z tank be compatible? Im doing the swap on a 1976 280z.... anything else i should know aswell?

[JZM]

No need to change the fuel tank.yes on the stock 240/260z fuel pump.

also make sure the int/exh gasket you use wiil seal the fuel injector holes,you should'nt have any problems with that though.

JZM..

[zman525]

ahhh... forgot about the fuel injector holes haha.... thanks prolyl woulda noticed when i got into it tho. i have an N42 head, but i have a stock 240z head layiin around, N42 better even if im running SU's and a stage 3 cam?

[240ZX]

You souldn't have to worry about the injector grooves on the head, as the SU intake will cover them, provided you use a gasket intended for SUs. Something to consider while you have the intake and exhaust off, replace all the old mounting studs, preferably with SS. Also, use a gasket that will actually make a seal. Retorqueing the fasteners after the engine has run for a while is a good idea for insuring a long term seal.

[Arne]

You don't need a mechanical pump, just any pump that puts out 4 to no more than 5 psi. Or you could even keep the injection pump if you use a pressure regulator set at 4-5 psi.

I did this last fall. Not to hard. Here is the summary:

http://classiczcars.com/forums/showpost.php?p=149555&postcount=6

[spikeyamir]

I have a question about the wiring to the injectors. Do I just get rid of it? and how. I've read all of the posts about the switch from FI to the SU's and haven't read anything about what to do with these wires. I just dont want to do something wrong.

Sorry for the dumb question.

Thanks.

[Carl Beck]

Something to consider while you have the intake and exhaust off, replace all the old mounting studs, preferably with SS.

I agree with the recommendation to replace the studs when you have the intake/exhaust manifolds off.

With water cooling running through the aluminum head - I would not recommend using Stainless Steel studs. Far less electrolysis, corrosion of the studs and galling will occur using the Cadmium plated steel studs from Nissan. The Cad. plating is a sacrificial coating, so new studs with their full depth of coating should always be used... and old studs that have given up their coatings should be discarded before they corrode.

FWIW,

Carl B.