Hey Prelude Fam. I have had my 1990 Honda prelude S (yes carb ) since I was 15. I have had it sitting for a while and was trying to get it back up and running which I have but it’s not running good. One of the reasons I stopped driving it was a gassy smell would come even inside the car and didn’t want to risk it. As I’ve been putting $ into get it back road ready. I’ve been considering just doing the swap to fuel injected versus rebuilding carb. Any tips or pointers or maybe a post or thread? Anyone done it before? Can the transmission be kept? Any help would be great. Also and suggestions to the gas smell? I know gas cap, possible catalytic converter, possible carb and muffler( no holes though)
Gas smell is likely from old rubber fuel lines or vacuum lines. I had a problem with a fuel smell and it ended up being over a dozen rubber lines that I had to replace. The car ran a lot better after I did that.
There's a lot of information here on doing this swap. Check the FAQ sticky at the top of the 3rd gen forum page. There's also the prelude3g.com site (Mustardcat's site). Here's a write-up from that site for the swap...
Yup, that write up has been established decades ago.
But the main points:
B20a5 complete motor/ECU
Either replace the entire harness or just tap into the existing harness and wire up the essentials.
you will need to install a Fuel pump, And a return fuel line. PGM-FI Main relay, located under the dash. Its an important electrical partHere is an aftermarket version if you choose to just add parts that make it Si - Main Relay Conversion with Kill Switch
Return fuel line, I used metal line routed under the car 10 Ft. or metal line
High pressure fuel line to replace the original fuel lines, 10 Ft.
High pressure fuel line to go from the fuel inlet pipe to the fuel filter
Fuel injector resistor
Vacuum Control Box - this part I believe you can by pass and just use a universal vaccum block to get all the necessary vaccum lines.
atmospheric pressure sensor (map)
Thats the just of the parts for the swap.
The write up tells you fairly detail on what to do.