Miles

Getting started: Download a Factory Service Manual (FSM). Buy the Datsun Z V8 Conversion Manual from Jags that Run (JTR). Download electrical schematics for your car. PDFs are easier to read than those found in books. Some are in color Buy the book How to Restore Your Datsun Z Car by Wick Humble. It will save you hours of searching for "how to" info. Focus on searching Hybridz as 99% of questions have already been addressed. Start bookmarking Z car parts suppliers - there are many! Remember these are 40 year old cars and will need restoration to be safe and drivable. Join ClassicZCars.com website and search there as well. Become well informed about modifications before asking questions. People will be more inclined to answer informed questions. Read all of the new member guidelines and FAQs Links: https://www.datsun-240z-upgrades.net/ Recommend the headlight relay harness http://zhome.com/ https://www.zcar.com/ https://www.classiczcars.com/ http://www.zcarparts.com/ http://www.arizonazcar.com/ http://www.jagsthatrun.com/index.html http://www.xenonzcar.com/reference.html

Looks like you have the correct sensor. The sensor could be defective.

Sounds like you have altered the stock wiring. So the following may or may not help you, but may serve as a process of elimination as you trace your electrical problem. Possibilities: Wrong oil pressure sensor? A wiring alteration is energizing the oil pressure sensor circuit when the ignition switch is in the start position and then de-energizes when the switch is released to run mode. Check the ignition, fuel pump and starting circuit wires. Check the circuits that have been altered to see if they have been cross connected to the oil pressure sensor. Test: connect a volt meter to the yellow and black oil pressure sensor wire. Note what the volt meter does as you turn the ignition switch slowly to each position on the switch. This will narrow down which wires to inspect. Look at/test these wires at each position on the ignition switch : Yellow-black - oil pressure sending unit Black-white (without protective sleeve) - tach terminal on HEI distributor Black-white (with protective sleeve) - battery terminal on HEI distributor Black-yellow - S terminal on starter Black-blue - energizes the fuel pump while cranking (260z and 280Z only). Note: 240z uses a green-white wire to run the fuel pump while cranking (energized just before start position on ignition switch. This is just a starting point. You have some detective work ahead of you.

Check your wiring to the oil pressure switch, oil pressure safety switch etc. If you followed JTR then your pressure switch and oil pressure safety switch should look like the attached picture. Post the wire list you used for the oil pressure switch etc and where each wire is connected.

Do a Google search of Hybridz.org: Copy and paste into the Google search window: site: hybridz.org "brake upgrades"

Read the brake FAQs and search the brake forum. Also search the internet by typing "240z brake upgrades". Note: stock brakes are fine

Welcome You may find this information useful: · Download a Factory Service Manual (FSM). http://www.xenonzcar.com/s30/reference.html · Download electrical schematics for your car. PDFs are easier to read than those found in books. Some are in color. · Buy the book How to Restore Your Datsun Z Car by Wick Humble. It will save you hours of searching for "how to" info. · Focus on searching Hybridz as 99% of questions have already been addressed. · Start bookmarking Z car parts suppliers - there are many! · For SU carbs, parts and instructions go to Ztherapy. Buy the "Just SUs" video. · Remember these are 40 year old cars and will need restoration to be safe and drivable. · Join ClassicZCars.com website and search there as well. · Become well informed about modifications before asking questions. People will be more inclined to answer informed questions. · Search the Hybridz forums. · Read all of the new member guidelines and FAQs Links: https://www.datsun-240z-upgrades.net/ Recommend the headlight relay harness http://zhome.com/ https://www.zcar.com/ https://www.classiczcars.com/ http://www.zcarparts.com/ http://www.arizonazcar.com/ http://www.jagsthatrun.com/index.html http://www.ztherapy.com/ http://www.xenonzcar.com/reference.html

I was going to suggest you contact Randy, but I no longer have his contact info. He used to advertise on Sacramento Craigslist.

Would that be Randy of Citrus Heights?

Welcome You may find this information useful: · Download a Factory Service Manual (FSM). http://www.xenonzcar.com/s30/reference.html · Download electrical schematics for your car. PDFs are easier to read than those found in books. Some are in color. · Buy the book How to Restore Your Datsun Z Car by Wick Humble. It will save you hours of searching for "how to" info. · Focus on searching Hybridz as 99% of questions have already been addressed. · Start bookmarking Z car parts suppliers - there are many! · For SU carbs, parts and instructions go to Ztherapy. Buy the "Just SUs" video. · Remember these are 40 year old cars and will need restoration to be safe and drivable. · Join ClassicZCars.com website and search there as well. · Become well informed about modifications before asking questions. People will be more inclined to answer informed questions. · Search the Hybridz forums. · Read all of the new member guidelines and FAQs Links: https://www.datsun-240z-upgrades.net/ Recommend the headlight relay harness http://zhome.com/ https://www.zcar.com/ https://www.classiczcars.com/ http://www.zcarparts.com/ http://www.arizonazcar.com/ http://www.jagsthatrun.com/index.html http://www.ztherapy.com/ http://www.xenonzcar.com/reference.html

In your part search contact Eric Neyerlin at https://zparts.com/ 541-670-7310 Eric has been collecting and selling Z parts for over 20 years

http://xenonzcar.com/s30/files/FSM/1975 Datsun 280z FSM.pdf

The part number you gave is for a relay inhibitor switch. You sure it is part of the light circuit? https://www.nissanpartsdeal.com/parts/nissan-relay-inhib-sw~b5230-89985.html The right half of your schematic is missing. Here is the complete schematic which shows the combination switch (lights, wiper, washer and turn signal). The combination switch is located on the steering column:

Contacts in the TS switch need to be cleaned and/or adjusted . Common problem for all Z cars. You can repair the TS switch. Search for turn signal repair. Start here: https://fiddlingwithzcars.wordpress.com/2012/12/04/turn-signal-repair/

You measure from the face of the aluminum spacer on the booster to the tip of the push rod. So, if you replaced the stock 7/8 MC with a 15/16 MC, which has a deeper socket, you adjust the push rod out 0.53"as measured from from the face of the aluminum spacer. The 0.53" is a starting point. You may have to fine tune the push rod length by making small changes and then road test the car to make sure the rod is as close as possible to the bottom of the MC socket without pushing the piston too far inward which will cause the brakes to drag or lockup. If the push rod is adjusted too long, the piston will block the return port in the MC and the brakes lock up after 2 or 3 stops. If this happens, open the MC bleeders to relieve the built up fluid pressure, limp home, and adjust the push rod a little shorter etc etc. If the pedal moves too much before engaging the MC you will need to lengthen the push rod in small increments. Note that you do not have to remove the MC to perform this adjustment. Just remove the mounting nuts and then pull the MC out and push it aside. There is also a tool to measure push rod length.

Look here: http://www.classicperform.com/TechBook/BrakeTroubleshoot.htm

Please post a picture of your front calipers.

Again I ask, what size MC did you install? Calipers require a larger volume of fluid. So the pedal goes low because the MC has to pump more fluid. You may have to install a 15/16 or 1 in. MC

one more thing to check. There is a push rod between the booster and the MC piston. The rod is adjustable. When you change MCs you have to adjust the push rod because the piston socket depth is different between the 7/8 MC and the 15/16 MC. Look it up. If the push rod is adjusted too long the brakes will lock up because the longer push rod prevents the piston from retracting all the way which blocks the fluid return port inside the MC. This will result in your brakes locking up after a few stops. If this happens while road testing just open the MC bleed screws and limp home and readjust the push rod. If the push rod is too short you will experience a long pedal because the piston is not pushed far enough to fully engage the brakes. That is, the piston is not pushing enough fluid. Your brakes will feel mushy and you will experience a pedal with long travel before engaging the piston Do a search for push rod adjustment. It is critical to properly functioning brakes and brake feel.

Do your speed bleeders work with your Motive power bleeder ?

Yep, p/n 639560 for the front calipers https://www.ebay.com/itm/Russell-Brake-Caliper-Speed-Bleeders-Front-Rear-for-1970-1973-Datsun-240Z-/192230009783

Edit Earl's speed bleeders from Summit. They come in several lengths. https://www.summitracing.com/search/product-line/earls-performance-solo-bleed-brake-bleeders?N=4294909157

See my last post. If you gutted the PV you may have now tied the front and rear brake circuits together which would explain fluid flowing between the tanks.