260z doesn't crank

[SteveJ]

Gas cap:

Motorsport! Gas Cap, 70-76 240Z-260Z-280Z - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

Black Dragon Automotive - Parts & Accessories for Datsun 240Z, 260Z, 280Z, 280ZX & Mazda RX7

240Z gas cap | eBay

Search the site for threads on waking up a car that has been sitting for a long time, too.

[zcool1]

thanks for all the advice so far ,

so now i'm back in LA for the time being and did the bypass it now cranks , interlock system failed so i had no power to starter.

anyway now i have a new problem no fuel.

ill be dropping the fuel tank tomorrow to see whats going on in there

and as for the carbs is there anything i can soak those in to possible get rid of varnish if any are there?

i did some reading and some people mentioned electric fuel pump with a relay, any advice on thaT?

[SteveJ]

Yes, search some more. I have posted several times on this board about the operation of the electric fuel pump. Also, the car should at least start with just the mechanical fuel pump.

More importantly, please search about waking up a car that has been sitting for a while.

[Captain Obvious]

new problem no fuel.

and as for the carbs is there anything i can soak those in to possible get rid of varnish if any are there?

Do you have the original flat top carbs on the car or have they been switched to the older round tops?

[darom]

I am wondering if that PO's wire splicing was part of his/her anti-theft solution? Basically, he disrupted the starter solenoid trigger wire with a switch or a relay?

Check to see if you are getting 12V at the elec. fuel pump terminals.

Before starting the car, I would drain/clean the fuel tank from rust, replace fuel filter, blow fuel lines from rust/debris etc.

[SteveJ]

I am wondering if that PO's wire splicing was part of his/her anti-theft solution? Basically, he disrupted the starter solenoid trigger wire with a switch or a relay?

Highly unlikely since the OP got his car to crank by going around the seatbelt interlock relay. The seatbelt interlock relay is notorious to anybody who owned a 1974 anything. My dad disabled it in the 74 Impala he owned. Most people just jumper the seatbelt switches. After careful study, I felt it was best to attack it at the emergency bypass since that will also give the most direct path between the ignition switch and solenoid.

Others have commented that the solenoid in their 260Zs weren't getting enough voltage. My SWAG is that they just jumpered the seatbelt switches and were still relying upon the interlock relay and therefore have another set of contacts in the circuit.

[zcool1]

Thanks again for the ongoing help guys.

Fuel tank is now off of the car.

Bad news * poured out 5 gallons of rusted orange fuel*.

will check fuel pump and lines tomorrow.

[zcool1]

ok so fuel tanks off ,

fuel lines not clogged,

but no fuel coming out of carbs.

electric fuel pump *dead*

what should i do now?

[SteveJ]

Did you change the fuel filters?

How do you know the fuel pump is dead? Did you check for voltage at the pump while holding the key in Start? Have you tested the pump with 12 VDC?

[zcool1]

Did you change the fuel filters?

How do you know the fuel pump is dead? Did you check for voltage at the pump while holding the key in Start? Have you tested the pump with 12 VDC?

yes sir pump is dead

following tests were done.

1.apply 12 volt source pump does not work.

2.check voltage while car was cranking zero 0.068 volts coming from connector.

3.remove electric fuel pump run hose from mechanical fuel pump to 1 gallon of gas .

4.check fuel lines and theyre filled with fuel *clean fresh fuel*

[SteveJ]

#2 could indicate a bad fuel pump relay. Just to clarify, you were measuring with the wires disconnected from the pump? Also, did you verify that one wire was grounded to the chassis? At this point, too, you would want to trace out the whole circuit to verify there isn't a bad fuse, fusible link or connector.

If your fuel pump is dead, you would need to replace it with a low pressure pump. I've heard of people using the one from a carburetted RX-7.

[zcool1]

1. yes the pump was tested off of the car .

2.fuel pump relay no idea where thats located if there is one.

3.also about the rx7 pumps i searched no one states clearly what year rx7 to get the pump from.