EFI relay pins 74 and 73 on my voltmeter i do see it has continuity but NO Beep

Fuel Pump Control pins 94 and 95 continuity but no beep   pins 91 and 95 continuity WITH BEEP

Fuel Pump relay pins 90 and 91 continuity but no beep

sorry if this is a dumb question

so does it matter if there is no beep on continuity even tho i do see some sort of continuity on the voltmeter

also it seems that im only getting 8 to 9 volts to the fuel pump

Having a weird issue ware new oem fuel pump was working.

 

any help is appreciated

 

First, let's go over terminology. This is important for clear communications.

Voltmeter - Measures voltage (difference in potential) across a source or a load, such as across the terminals of a battery.

Ammeter - Measures current flow through wires.

Ohmmeter - Measures the resistance (opposition to current flow) of a load.

VOM - Volt Ohm Meter: This is a meter designed to measure voltage or resistance

Multimeter - A meter that at a minimum measures voltage, resistance, and current. Some multimeters can measure frequency or inductance, and others have functionality to test transistors.

Autoranging - A VOM or multimeter that will automatically select the range for the display, going up or down orders of magnitude.

Continuity - Continuous, as in a continuous piece of wire.

Now let's talk about resistance. Wire has resistance. Connections have resistance. Both should be low enough that we can ignore it if things are in good working order. Even a VOM or multimeter has resistance. An air gap has very high resistance. 

If you are using a digital VOM/multimeter with autoranging, the first thing you do is set the meter to measure resistance. The display will typically show OL (open line), and there will probably be a capital M near the reading to show megaohms. Touch your leads together. The display should go down to less than 1, and the M should disappear. If the meter has a continuity buzzer, it should be buzzing at this time. Please note that the threshold for a continuity buzzer may be several ohms. The autoranging feature will change the display, possibly without you realizing it. It can go from megaohms, to kiloohms, and to ohms virtually instantly, so you have to watch for the M or K on the display.

If you have to set the range manually on your VOM, start with the LOWEST range when you are checking for continuity. Touch the leads together and make sure the reading goes down to less than 1. If you are using a higher range, the display may read less than 1, but you could have a lot of resistance.

My philosophy when checking continuity is to IGNORE THE CONTINUITY BUZZER. The value on the display is important.

So go back and start over. Have a notepad with you to record readings.

Also, where exactly are you placing the probes for the meter? Be specific so we can tell whether or not your technique is correct.

Finally, what year Z do you have? There are differences, and if you need help, we need to know which FSM to refer to.

Feel free to post a photo of your meter so we can verify what setting to use on the dial.

First, let's go over terminology. This is important for clear communications.
Voltmeter - Measures voltage (difference in potential) across a source or a load, such as across the terminals of a battery.
Ammeter - Measures current flow through wires.
Ohmmeter - Measures the resistance (opposition to current flow) of a load.
VOM - Volt Ohm Meter: This is a meter designed to measure voltage or resistance
Multimeter - A meter that at a minimum measures voltage, resistance, and current. Some multimeters can measure frequency or inductance, and others have functionality to test transistors.
Autoranging - A VOM or multimeter that will automatically select the range for the display, going up or down orders of magnitude.
Continuity - Continuous, as in a continuous piece of wire.
Now let's talk about resistance. Wire has resistance. Connections have resistance. Both should be low enough that we can ignore it if things are in good working order. Even a VOM or multimeter has resistance. An air gap has very high resistance. 
If you are using a digital VOM/multimeter with autoranging, the first thing you do is set the meter to measure resistance. The display will typically show OL (open line), and there will probably be a capital M near the reading to show megaohms. Touch your leads together. The display should go down to less than 1, and the M should disappear. If the meter has a continuity buzzer, it should be buzzing at this time. Please note that the threshold for a continuity buzzer may be several ohms. The autoranging feature will change the display, possibly without you realizing it. It can go from megaohms, to kiloohms, and to ohms virtually instantly, so you have to watch for the M or K on the display.
If you have to set the range manually on your VOM, start with the LOWEST range when you are checking for continuity. Touch the leads together and make sure the reading goes down to less than 1. If you are using a higher range, the display may read less than 1, but you could have a lot of resistance.
My philosophy when checking continuity is to IGNORE THE CONTINUITY BUZZER. The value on the display is important.
So go back and start over. Have a notepad with you to record readings.
Also, where exactly are you placing the probes for the meter? Be specific so we can tell whether or not your technique is correct.
Finally, what year Z do you have? There are differences, and if you need help, we need to know which FSM to refer to.
Feel free to post a photo of your meter so we can verify what setting to use on the dial.

Jeez, I'm just going to copy and paste this to a word document, print it, and tape it to the wall. If you don't mind of course.

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Might take two walls. 

Jeez, I'm just going to copy and paste this to a word document, print it, and tape it to the wall. If you don't mind of course.

Sent from my N9130 using Tapatalk

Meaning that this response is, in a nutshell, almost everything one needs to navigate the world of electronic diagnostics. No need for a manual. Wasn't trying to insinuate that the response was too lengthy.

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1 hour ago, Reptoid Overlords said:

Meaning that this response is, in a nutshell, almost everything one needs to navigate the world of electronic diagnostics. No need for a manual. Wasn't trying to insinuate that the response was too lengthy.

Sent from my N9130 using Tapatalk
 

I agree.  Great respect for Steve and his detailed replies.  He's helped me many times and I too think this would be a great document to save.

On 2/14/2019 at 8:15 PM, nefiwashere said:

 EFI relay pins 74 and 73 on my voltmeter i do see it has continuity but NO Beep

Fuel Pump Control pins 94 and 95 continuity but no beep   pins 91 and 95 continuity WITH BEEP

Fuel Pump relay pins 90 and 91 continuity but no beep

sorry if this is a dumb question

so does it matter if there is no beep on continuity even tho i do see some sort of continuity on the voltmeter

also it seems that im only getting 8 to 9 volts to the fuel pump

Having a weird issue ware new oem fuel pump was working.

 

any help is appreciated

 

Now it looks as though you may have a 78 280Z. The PITA is that the wiring diagram doesn't have the pins numbered. There is some numbering on EF-26, so I will use that.

Pins 73 & 74 are a coil. You should have some resistance. I don't have the spec for that coil handy, but I measured a couple of standard automotive relays. The coil on one relay measured about 83.6Ω, and the other was 78.7Ω

Pins 90 and 91 also are for a coil. There should be resistance.

Pins 94 to 95 I believe are for another coil. Again, you should have resistance.

Pins 91 to 95 are for a normally closed contact. With the relay unplugged, you should have continuity (nearly 0Ω resistance) across those pins.

Search through the old posts on this site. I know I have talked about these relays in the past.

Oh, and clean your old connectors. Many people swear by Caig Deoxit.

Thank you for the very detailed reply,   i will need to retest my relays to get a curate info as requested.  

 

I did Use a Electrical Connector cleaner from AutoZone  before reading the suggestion by another members post.

Another issue it seems im running into is that my fuel pump is not pumping as it should.   At cold start car starts normally, let it warm up for a good bit.    I drove it around my neighborhood, about  2 miles and it started struggling. when i pulled up to my house i checked the fuel pressure and it was at 20psi and clear fuel filter by the pump was 3/4 empty.   Yes there is gas.   same thing that happen before but i thought i had ran out of gas.      Gas Gauge is Semi faulty so i just added another 5 gallons of gas the first time it happen.

More info on issue.

So letting the car sit for about 10 minutes, fuel pressure still at 20psi. I started it up and fuel pressure at 48 psi and fuel filter is filling up with gas.


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Set dial on ohms 2M. All relay tests came out to .000. Except 1 it fails.



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There appears to be a significant disconnect between what I described and what you did.

For resistance, you should start with the lowest setting. That would be 200Ω and not 2MΩ.  This is important. In my previous post, I said I measured 78.7Ω across the coil. That would be 0.0000787MΩ, or on your display, 0.00MΩ. This is important. If the coil was shorted out, the resistance would be much less than 78.7Ω, but your meter would still give you the same reading as a good coil if you use the 2MΩ scale.

As for the test that you said failed, what were you using for your 12VDC source? Did you hear a click in the relay (possibly 2 clicks)?

Try this test: Put the positive from the 12VDC source on pin 95. Connect the negative to pins 94 and 96. Put your meter on the  200Ω setting and measure resistance across 91 and 97.

Here is the theory of operation for that relay:

If there is voltage across pins 95 and 94, the coil is energized, and the the contact near pin 96 closes. Now there should be voltage across pins 95 and 96, and the second coil is energized. That causes the relay to move the switch that connects 91 and 95 so that it now connects 91 and 97. This is all relatively binary. Either the circuit is open or closed. Either the coil is energized, or it is not. If there is a voltage drop, it could be from the contact between 91 and 97 getting pitted or dirty so that there is not good contact. This would act like a resistor in the circuit.

If the car runs, the relay works. However, the fuel pressure should not be at 48 PSI.

I think you're barking up the wrong tree.

I had a 1976  combined pump and EFI relay that would overheat and have a coil go open circuit.  The coils were a little bit burnt.  You can peel the little tabs back and remove the cover.  After you finish the tests.  Good practice on meter operation and test procedure.

 

 

12 hours ago, SteveJ said:

There appears to be a significant disconnect between what I described and what you did.

For resistance, you should start with the lowest setting. That would be 200Ω and not 2MΩ.  This is important. In my previous post, I said I measured 78.7Ω across the coil. That would be 0.0000787MΩ, or on your display, 0.00MΩ. This is important. If the coil was shorted out, the resistance would be much less than 78.7Ω, but your meter would still give you the same reading as a good coil if you use the 2MΩ scale.

As for the test that you said failed, what were you using for your 12VDC source? Did you hear a click in the relay (possibly 2 clicks)?

Try this test: Put the positive from the 12VDC source on pin 95. Connect the negative to pins 94 and 96. Put your meter on the  200Ω setting and measure resistance across 91 and 97.

Here is the theory of operation for that relay:

If there is voltage across pins 95 and 94, the coil is energized, and the the contact near pin 96 closes. Now there should be voltage across pins 95 and 96, and the second coil is energized. That causes the relay to move the switch that connects 91 and 95 so that it now connects 91 and 97. This is all relatively binary. Either the circuit is open or closed. Either the coil is energized, or it is not. If there is a voltage drop, it could be from the contact between 91 and 97 getting pitted or dirty so that there is not good contact. This would act like a resistor in the circuit.

If the car runs, the relay works. However, the fuel pressure should not be at 48 PSI.

I think you're barking up the wrong tree.

attached pic of the values.   there are 2 different readings per test.  Used 2 meters to test with.   

95-91 and 93-92  my readings were very different between the 2 tests

still need to do the 97 to 91 test