Need help identifying oem engine bay components

[sYnth]

Hey all,

Recently purchased a 91 NSX and am trying to restore what was once a heavily modified car to a more stock/oem+ state. I noticed I am missing a couple components in the engine bay and was hoping someone could help me ID what they are.

Thank you!

 

[Old Guy]

The green circle on the left is the fuel pump resistor. In the right circle, are you referring to those two rubber boots? If so they are the rubber boots protecting the chassis ground terminals G102 and G181. You will not have G181 because that is associated with the start up secondary air system that was applied to 2000 and later cars. However, a 1991 would have had other stuff in that area such as the engine compartment fan. Honda ditched that fan sometime after 1991; but, may have used some of the mounts for the secondary air system.

G102 was originally for the engine cooling fan; but, got repurposed to some other function on later cars so your 1991 may no longer have G102 if the engine cooling fan was removed.

What model year is that photo from? Best to get a copy of the 1991 service manual for determining what is what.

 

[sYnth]

The green circle on the left is the fuel pump resistor. In the right circle, are you referring to those two rubber boots? If so they are the rubber boots protecting the chassis ground terminals G102 and G181. You will not have G181 because that is associated with the start up secondary air system that was applied to 2000 and later cars. However, a 1991 would have had other stuff in that area such as the engine compartment fan. Honda ditched that fan sometime after 1991; but, may have used some of the mounts for the secondary air system.

G102 was originally for the engine cooling fan; but, got repurposed to some other function on later cars so your 1991 may no longer have G102 if the engine cooling fan was removed.

What model year is that photo from? Best to get a copy of the 1991 service manual for determining what is what.

This is extremely helpful and answered all of my questions. Fan has definitely been deleted and I guess the fuel pump resistor was also deleted at some point (car was turbo’d in its past life so who knows what fuel set up it has been through. Thank you!

 

[Old Guy]

If it had a turbocharger, I expect that they would have been using an aftermarket ECU which would likely not be set up to deal with the low / high voltage supply utilized with the OEM fuel pump. They probably just deleted the relay which by-passes the resistor at high load along with the resistor itself. It is safe to do that, you just get to live with more fuel pump noise at low engine load and perhaps a nudge shorter fuel pump life.

 

[JohnWayne]

This is extremely helpful and answered all of my questions. Fan has definitely been deleted and I guess the fuel pump resistor was also deleted at some point (car was turbo’d in its past life so who knows what fuel set up it has been through. Thank you!

If you need an engine fan, I have one.