No power to fuel pump or spark plugs

Discuss the RB20, RB25 and RB26 series engines.
reuhzaki
Posts: 103
Joined: Sat Mar 03, 2012 8:14 am
Car: 1991 240sx s13

No power to fuel pump or spark plugs

Postby reuhzaki » Mon Apr 20, 2020 8:29 pm

Any help would be appreciated. So I have a 1991 240sx that I’m swapping an rb20det into. I have wiring specialties engine and transmission harnesses. The car won’t start☹️. I’m not getting power to the fuel pump nor the spark plugs. I took the cas off and saw that the key is broken. I know this could result in no start but shouldn’t I still be getting power to the pump and plugs.? Is there something else I’m missing?


jacob005
Posts: 11
Joined: Wed Nov 06, 2019 2:50 pm
Car: R32 Skyline GTS-4

Re: No power to fuel pump or spark plugs

Postby jacob005 » Thu Jul 16, 2020 11:35 pm

Yeah on my skyline the pump runs for a second once you turn the key to On.

I dont know anything about their harness, but on the skyline both the fuel pump and the coils get power from their own relay

reuhzaki
Posts: 103
Joined: Sat Mar 03, 2012 8:14 am
Car: 1991 240sx s13

Re: No power to fuel pump or spark plugs

Postby reuhzaki » Fri Jul 17, 2020 3:59 am

Ok so power goes from battery to ignition,relay, then to pump? Perhaps wiring problem from ignition to pump. I appreciate the reply

jacob005
Posts: 11
Joined: Wed Nov 06, 2019 2:50 pm
Car: R32 Skyline GTS-4

Re: No power to fuel pump or spark plugs

Postby jacob005 » Fri Jul 17, 2020 1:26 pm

No it looks like they each get their own wire from the ignition circuit. But on my car I rewired the pump relay so that when the relay is triggered it takes power from the battery. It looks like the coil relay is triggered by the same pin as the ECCS relay, so it should come on with the computer.

But this is all for a factory RB20 setup. Is your swap harness an exact copy? Can you get a diagram off of wiring specialties?

If I were you I would fix the CAS first. The car obviously wont start if the computer doesnt know that the engine is spinning. The pump only runs for a second with key on, then waits until the engine cranks over.
Attachments
rb20det circuit diagram.png

reuhzaki
Posts: 103
Joined: Sat Mar 03, 2012 8:14 am
Car: 1991 240sx s13

Re: No power to fuel pump or spark plugs

Postby reuhzaki » Sat Jul 18, 2020 4:44 am

I see. Thank you for the information. They do have a wiring diagram but the wiring that leads to the fp is factory (not part of the engine harness. I tried visually aligning the cas, probably not very accurate though


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