Quote:
Originally Posted by Super_OK_S13
d1zguy2- I Hope this one helps, i tried to get as close as possible with a bunch of different pics and they all get blurry.. try and download it for the full resolution. Colum EThe stuff in the top right is for the door switch and dome light wiring. the plugs on the top right (i wrote white/black) are for the cluster. the bottom right is relays for the accessory (left), fan (middle), and ignition (Right). hope that helps !!!  |
HB01 fuse, joins and protects 12v coming from DB08 that goes to the ACC relay gets power from DA12 that is connected to battery voltage at DB10 when DAE3 and DA15 close and engage the relay for that connection to happen when ignition is turned on
Grabbed my power probe and no dice on the old relay, wasn't clicking on and bridging the contacts.
Probably worthwhile to replace the ACC, Fan relay, and ignition relays while I am there to lower resistance on all those old contact points. Now does anyone have the part number for that funky old Nissan ignition relay?
Also, I think better quality can be achieved by using a scanner, got one at work you can borrow? lol Scan to USB
Now my blitz gauge must just be faulty. It got stuck in the short circuit sender or missing sender mode and when I pulled the power to it and powered it back on it reads 70c no matter what, sender connected or not. Guess just sender shorted or something and fried the blitz who knows
Also, My silvia had a fuel pump control module, basically alternated voltage to pump between idle and off idle to control fuel pressure, since I wired my FP directly to fuel pump and used the OEM power wires to trigger the relay, I just disconnected the fuel pump control module to get rid of that unnecessary load, and I guess that module also always kept some current live; enough to keep my relay triggered at times, disconnecting solved my issue of an always running fuel pump upon key on instead of priming for a few seconds and then off, and also no longer remaining on sometimes until I tapped the FPR relay to get it to stop.
So if you're using the OEM wires to trigger your FP relay make sure you disconnect this fuel pump control module! and also why it's important to wire your fuel pump directly once you go bigger injectors adjustable FPR, if the ECU is playing with pump speed you'll never get your fuel and tune dialed rigght on a JDM silvia K's, don't know if USA KA's have this setup prob not too expensive to do for a D21 truck engine I bet lol
Z32 300ZX have the same setup
After much gnashing of teeth, and reading about other people having similar problems, I used search extensively and found the answer to properly checking fuel pump voltage.
Somebody posted the other day (and I had the same problem) that if you check voltage on the white wire to the fuel pump to chassis ground you will get about 7.7V at idle. If you step on the gas it drops to 6.xV and if you go WOT it will drop to about .6V which seems pretty scary.
What's actually going on with that signal wire can be found in this old post by Buzz
Since the controller is actually providing a GROUND path, to properly check what voltage is really going to the pump you need to wire your positive lead on the meter to the ORANGE wire of the pump (this is battery voltage) and the negative lead to the white (signal) wire of the pump. It's the DIFFERENCE between these two that tells you your actual voltage, not the difference between them and chassis ground.
Ex: doing it this way you will see battery - signal at idle = 13.5V - 7.7V = 5.9V which is exactly in spec.
At WOT it's 13.5V - .6V = 12.9V which is what you would expect.
In my case, this proves that my controller is working properly so my fuel pressure problems are somewhere else. I'm looking for restrictions next.
Hope this helps some of you. It was driving me crazy. Thanks to Buzz for posting that a while back. (Thanks to me for search LOL)
you can see here that 12V power to the fuel pump is actually a constant 12V. This signal is uninterrupted by the FPCM. The Orange wire gets power from the fuse box and once switched sends it directly to the fuel pump. The FPCM actually comes into play on the ground side of the pump. Why? Because the FPCM is actually a variable resistor that increases resistance to ground when commanded by the ECU. If the FPCM gets no signal from the ECU, the fuel pump gets a zero resistance ground (Translation = Full Pump Speed). When the ECU sends a ground signal to the FPCM over the Purple and/or Black/Pink wires the FPCM increases the resistance which in turn lowers the pump speed.
All in all all the electrical issues and gremlins are solved on the Silvia! and linkecu is setup and running now