Slowly learning everything I can about the EFI system on my 77-280Z.  I'm fortunate to have a 77K mileage car that runs great, just really tired looking under the hood.  I have purchased another EFI system that has been cleaned up and shaved of the EGR.  Its my desire to slowly switch over things and learn along the way. .

Can someone tell me the purpose of the attached water inlet under the air regulator.  It was omitted from the system I purchased and I wonder what impact this might have on performance of the EFI.   I have been unable to find it in the FSM.  Thank you

 

 

Edited February 9, 20178 yr by Jaymanbikes

Like you, I have been fiddling in that area and wasn't able to find it in the manual.  My guess is that it circulates coolant under the AAR to assist in closing it as the engine warms.

Mentallite is correct.  It is a block under the AAR that the coolant loops thru to heat the bi-metallic spring in the AAR.

In the 1st picture, the factory steel lines have been replaced with braided hose,  they likely failed due to age & corrosion.  (a fact I can attest to)

  On 2/9/2017 at 2:02 PM, S30Driver said:

Mentallite is correct.  It is a block under the AAR that the coolant loops thru to heat the bi-metallic spring in the AAR.
In the 1st picture, the factory steel lines have been replaced with braided hose,  they likely failed due to age & corrosion.  (a fact I can attest to)

Thanks guys, that was my guess, also explains why the hoses seem to be a home-made retro..


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I've always heard it called a warming plate for the AAR, like said above.  When you delete the EGR that has to go as well.  The thermal vacuum switch has hoses going to the BPT then to the bottom of the throttle body.  When you swap that over you'll want to plug that hose, I put a small bolt in mine, circled in yellow in my picture.

Curious, did you buy Geoff's aka rossiz system?  

  On 2/9/2017 at 2:45 PM, siteunseen said:

I've always heard it called a warming plate for the AAR, like said above.  When you delete the EGR that has to go as well.  The thermal vacuum switch has hoses going to the BPT then to the bottom of the throttle body.  When you swap that over you'll want to plug that hose, I put a small bolt in mine, circled in yellow in my picture.

Curious, did you buy Geoff's aka rossiz system?  

Ahh, that makes sense.  Yes, I did buy his set-up from him, thanks for the tip on that one BTW.    Hopefully going to save me a lot of time and dollars as opposed to fixing my old system up. 

  On 2/9/2017 at 2:45 PM, siteunseen said:

I've always heard it called a warming plate for the AAR, like said above.  When you delete the EGR that has to go as well.  The thermal vacuum switch has hoses going to the BPT then to the bottom of the throttle body.  When you swap that over you'll want to plug that hose, I put a small bolt in mine, circled in yellow in my picture.

Curious, did you buy Geoff's aka rossiz system?  

siteunseen, question about your blue/black hose routing.  Yours is routed the same as my factory set-up.  Geoff's is reversed, doesn't seem to matter, would you agree?

Those hoses were changed from '77 to '78's.  I rerouted mine to the '78's, it feeds the AAR with cleaner air if I remember right.

Here's the way I ran mine after reading about that issue with the '77's.

 

 

 

Edited February 9, 20178 yr by siteunseen

That hose I plugged appears to go to the BCDD after looking closer.  I think it is considered "ported vacuum"?  That was a few years/beers ago when I did mine and a lot of reading and asking questions on classiczcars.com.  

  On 2/9/2017 at 3:41 PM, siteunseen said:

That hose I plugged appears to go to the BCDD after looking closer.  I think it is considered "ported vacuum"?  That was a few years/beers ago when I did mine and a lot of reading and asking questions on classiczcars.com.  

Here is the set-up I received.  I have not seen a fuel rail run in this manner, looks clean.

He may have gotten the idea from @Blue?  But if you'd seen the motorcycles Geoff built he probably saw the simplistic solution himself.