280z cranks but won’t start

[silentbug]

Thank you


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[silentbug]

I checked the AFM and it moves freely but I have not checked the TPS
The the fuel pump is hook up correctly and I made sure it wasn’t just running off the cold start injector
I found so cracked vacuum hoses and the water temp sensor is broken


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[silentbug]

And I have a multimeter but still a little new at using it


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[silentbug]

And I still need to check the two things Steve suggested


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[Zed Head]

3 hours ago, silentbug said:

I found so cracked vacuum hoses and the water temp sensor is broken

There are two temperature sensors up there.  One is for the gauge, it has a single terminal, the other is for the ECU, it has a connector like a fuel injector (EV1 style).  The one for the gauge is usually called a sender, not a sensor.

If the sensor for the ECU is disconnected the engine will flood with fuel, because the ECU "thinks" that it's -40 degrees.  The water temperature sensor needs to be connected.  You can test the pins at the ECU connection to be sure it's working correctly.  There's a chart in the FSM and in that book that show what the resistance should be.

[EuroDat]

Steve mentioned two possabilities before you added the a post saying it idled for 5 seconds and sounds rough.

I think that points to fuel delivery. With the ignition switch the engine should die immediately when the key goes from Start to ON. No power to the fuel pump will mean the engine dies slowly after about 5 seconds of rough idle.

You might want to invest in a simple pressure guage to measure fuel pressure 0-50psi. You could have very poor fuel pressure and where it starts on the Cold Start Vavle, which is basically a large injector, and then doesn't have enough pressure to run on the normal injectors.

[siteunseen]

An easy way to get a guess at fuel pressure is to simply try and pinch or squeeze the hoses. The one coming off the top of the metal filter should be as hard as rock. Then go further upstream and pinch the one that feeds the CSV. The one from hardline to rubber before the injectors etc. Good luck.

Edited January 26, 2021 by siteunseen

[Zed Head]

On 1/25/2021 at 10:40 AM, silentbug said:

I had a bad tank in the car so I made my own using a gas can and hooked it up to the exit and entry parts for the fuel rail
Won’t idle for more the 5seconds and if it idles it sounds rough
The gas pedal get stuck when you push it down

 

On 1/25/2021 at 12:01 PM, Zed Head said:

What kind of fuel pump did you use? 

 

On 1/25/2021 at 12:11 PM, silentbug said:

Thanks I have been look at some manuals to buy and the fuel pump that I bought was an aftermarket on built for scars it puts out around 40-45 psi

 

5 hours ago, silentbug said:

The the fuel pump is hook up correctly and I made sure it wasn’t just running off the cold start injector

 

1 hour ago, EuroDat said:

Steve mentioned two possabilities before you added the a post saying it idled for 5 seconds and sounds rough.

I think that points to fuel delivery. With the ignition switch the engine should die immediately when the key goes from Start to ON. No power to the fuel pump will mean the engine dies slowly after about 5 seconds of rough idle.

He built his own small fuel supply system in the engine bay, apparently.  I don't think the ignition switch is involved at this point.

I should add to my other point about the temperature sensor that if the wires are shorted the opposite problem occurs.  The ECU thinks it's very hot and cuts fuel supply down.

If we were all standing around the car pointing at things it would probably be running by now.  But I think he needs to get that meter out and take just a few measurements.  EFI is more about electricity than the mechanical stuff.

 

p.s. finally figured out exactly how this "multi-quote" thing works.  It's weird how these programmers will put all of these cool features in to their work but not give any instruction on how to use them.  All of that coding effort, gone to waste for most.  Wonder what else I'm missing.

[Patcon]

1 hour ago, Zed Head said:

 

p.s. finally figured out exactly how this "multi-quote" thing works.  It's weird how these programmers will put all of these cool features in to their work but not give any instruction on how to use them.  All of that coding effort, gone to waste for most.  Wonder what else I'm missing.

Amen!!!

[siteunseen]

They say curiosity killed the cat. I have buried some cats! 

If there's something to click on I'll click it. Amazing what my dumbass has learned on these things being curious. Now I'm finally figuring out these smart phones and my 13 year old nephew laughs at me like I'm the guy that keeps pushing the elevator button.

Oh yeah Zed Head. You reply to each quote as you go. Don't load up up at the end.

Edited January 26, 2021 by siteunseen

[silentbug]

Hey I got finials and won’t work on the car till Thursday or Friday if you guess think of any more ideas please post them and I’ll test them and thank you all for all your help so far


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[silentbug]

Hey sorry I have had bad weather the last two days so I’ll work on it tomorrow


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