wiring a ignition relay required on rb20det in 280z ????

[twistex]

i read the write up on a rb25det in a 280z .. i know the connector that use to power the 280z efi. well i hooked everything up and well im having weird problems like tps having 12v instead of 5 and all that. im thinking i need to wire up a relay for my ignition wires for rb20det ecu and just use the 280z plug to trigger relay ? on rb20det only a few wires.. white/purple blk/red blk/white constant and 2 switched. of course your tacho wire, temp wire, fuel pump ground i wired into a relay and that works with ecu, does 280z already have relays that are connected to that old efi plug somehow ?

[mjfawke]

RB20DET loom requires separate switched 12v for the EGO heater. Goes into the same same plug as the start/ign/tacho wires. As for 12v for your TPS... I don't see how this is possible.

[Z U L8R]

white/black = constant 12volts

black/red and white/purple = 12v ignition power

 

on the rb20 harness where there's 2 green relays. only use 1 relay, leave the ignition coil relay out. i just finished an rb20 into 240z this weekend. when both relays were plugged in the safc and ecu would not turn off, and if you put the white/black wire on 12v ignition power instead of constant the car runs rough as if the coils are not getting enough power. the only difference with this particular 240z and your 280z may be that his 240z, i already have the wasted spark set up on it, which basically eliminates the coil on plugs and uses a 87 buick grand national 3.8 coil pack /w 6 spark plug wires. on the underside of the coil pack is 2 rows of 3 posts. one row is 12volt ignition power on all 3 tabs which gets it's power via the rb20's engine harness from the 3 pin grey oval plug that's right next to the ignitor plug. that thick white wire feeds the ignition 12v to the 3 tabs. that thick white wire is also the wire you clip msd part # 8918 tach signal pick up to, in order to use an autometer tach. then for the other 3 posts you use the coil pack's harness that plugs into the ignitor. then run your ignitor's 6 wires to the other row of 3 tabs on the underbelly of the grand national coil pack, with the ignitor's ground signal for cylinder's 1 & 6, on one tab, 2 & 5, on another, 3 & 4 on the last tab.

 

in any case sheesh! your tps should be 3 wires, one ground, one 12volt, and one rheastat'd 0-? volts.

 

what's the car doing or not doing that it should be? i'm trying to figure out why are you testing voltage in your tps in the first place?

[chrism]

You can go to the download section on the main page and get the RB FSM. It will walk you through the diagnostics for ignition. It will also tell you what type of voltage you should be getting when the car is off or when it is running. One thing to you will need to be aware of is that the FSM has all the RB series engines documented and you will have to sift through looking for what pertains to the RB20. Also the pictures of the engine and some of the drawings really really really suck. so just look at the diagnostic flow chart to help you determine if what you are reading is normal. Hope this helps. It helped me and I don't know jack about the RB20. I do now.