Jump to content
SAU Community

Recommended Posts

Hi...i have a problem with my L20et engine...i got the engine from a buddy but the fuel pump relay and EFI relays are missing and don't know where on the ECU the wires for those relays are located...i wanted to know if you can send me a picture or a wiring diagram for this engine please or if you can tell me what pins on the ECU is the wires. Its the original 3 jack type ECU, its also an uncut harness, all the other wires are connected in place straight from the factory from years ago...I could be wrong in asking for this because I don't really know if the ECU controls the fuel pump relay & the E.F.I relay, but i've been looking at L28et diagrams and I saw these relays and thought that since the L20et & L28et are so similar they both should have the same components...but didn't know they had 2 different ECU setups :(

Another thing I wanted to know is if the L20et works with a high pressure fuel pump because the engine isn't in an R30 Skyline, its in a C32 Laurel which originally came with an L24 Carb engine with a low pressure fuel pump which i swapped out with a RB25DET fuel pump. So I was just wondering if anybody can help me with this tiring situation. Thanks!

post-110910-0-84424100-1366966433_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/424177-l20et-wiring/
Share on other sites

yes l20et uses a high pressure fuel pump.

Ecu does control the fuel pump, but actually controlled a Varible controller set under the parcel tray for fuel pump voltage control (noise levels), Isnt the rb25 fuel pump internal ?. Either way if its installed corectly it wont have any problems

For fuel pump power find a iginition source and wire in your own relay with a good power feed from the battery. From what i worked out the l20et ecu doesnt have a rollover protection device that kills the fuel pump, so the only benifit it does is a priming cycle on ignition on. So you will not be missing much.

ECU feeds power to the injectors directly. I know this might not be much help. This is what i fouind when stripping my harness down, I do have a book that covers 90% of the wiring in Jappa's and AUS R30's that ill have a look to see what i can find for you

  • Like 1
Link to comment
https://www.sau.com.au/forums/topic/424177-l20et-wiring/#findComment-6828715
Share on other sites

Thank you so much for replying mate!..and great advice i would of never thought about connecting it to an ignition..cause i was afraid i blew something lol.

Yea the rb25 is and internal pump...but here's the problem i've been facing...when i connect the fuel directly meaning i just ground it and connect the other end to the battery and start the engine it runs for a minute and cuts off...when i disconnect the pump the car starts and idles and revs but as soon as the rpm comes back down from revving the car cuts off...i have the fuel regulator set at 40psi by the way....when i just connect the pump for 3 seconds to pressurize the rail and start the car its starts and idles for 7 mins without the fuel pump on but as soon as i rev it the car cuts off...but if keep pulsing the wire for the fuel pump on the battery off/on off/on the car works fine...and when i want it to idle i just have to disconnect the pump and when its about to cut off give it the 3 seconds connection. This is when i realized that the fuel pump relay and EFI relays were missing and was controlled by the ECU.

Link to comment
https://www.sau.com.au/forums/topic/424177-l20et-wiring/#findComment-6829033
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • @soviet_merlin Thanks mate!  Nothing too major but will hold me up for a while. I've got lymphomas to get taken off the back of my neck and the middle of my spine which always conjures scary thoughts!  It sounds worse than it is. Yeah great, conjuring more rabbit hole deepening , just what I need! 🤣  
    • I'd argue the F50 kit I got is very good value. For ~2k I got the calipers (refurbed condition), adapters, pads, brake lines, rotors, and top hats. I think you'd be pretty hard to get Evo/GTR/350z brembos + the additional hardware for similar money. Used market for a pair of front calipers alone I've seen tend to run anywhere from $1500-2000 depending on condition.    That said, something like a GTR or 350z brembo is a lot easier to adapt to the Silvia. 
    • Is there a significant price difference between the Evo/gtr/350z brembos vs the F50? Looks amazing.
    • I was actually being a tightarse at the time LOL... My OCD is tickling me into running a 2nd 8AN Teflon hose all the way down and removing the 2x OEM hardlines. My other side of my brain is telling me to run 2x hardlines front to back (also acts as a fuel cooler, so win win).
    • As I mentioned in an earlier post, I had some trouble with the Silvia's brakes dragging back in 2023. I managed to sort it out then, but the same problem came back to bite me late last year. Just take a look at the picture – I had a feeling the handbrake was acting up again, and I was right. Anyway, I'd been wanting to upgrade to bigger brakes for a while. Not that the Silvia's brakes were bad, but it was more of a "want" than a "need", you know? It was funny, though – at the time, I couldn't find any Evo Brembos, 350Z Brembos, or GTR Brembos for a decent price (of course, tons of them popped up online after I already bought my kit!). I ended up going with an F50 Brembo kit, which came with adapters, brake lines, 330mm rotors, and top hats. The F50 Brembo caliper was used in a few other cars too, like the FPV. I also decided this was the perfect opportunity to ditch the Silvia's ridiculous rear brakes and that awful handbrake (some of you were definitely right about that!). I picked up some R33 calipers and all the necessary bits – rear drums, backing plates, and new hardware to refurbish the calipers. Of course, it wouldn't be a project without a few hiccups. Turns out the brake master cylinder was playing up and basically (to put it simply) keeping the brakes engaged. I had it overhauled, and after some adjustments, everything was working again. The whole process took a while, as you can imagine. To top it off, the front right wheel bearings were shot and needed replacing too. This is a rare occasion where I'm posting an update while it's all still fresh! These pictures were taken just this afternoon.
×
×
  • Create New...