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1983 Datsun 280zx
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Discussion Starter · #1 ·
This morning my vehicle died on me like the description says. Ran fine yesterday. There have been some ignition start issues prior but wants cycling through the key it would resolve itself on the second turn. Previous owner did have some ignition rebuild and the receipts I got in the past. Only things I've done since receiving the vehicle is replacing spark plugs spark plug leads distributor cap and rotor and a few lines of vacuum tubing. I also replaced the fuel filter engine oil and engine oil filter and the PVC valve. All that work was done before I drove it around yesterday to and from work.

Does anyone have an idea of what would cause the engine to die like that after going up a short Hill then not be able to start again?
 

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Could be a clogged fuel line. I know you just changed the filter but you could have some sediment in the fuel. I have a fuel pressure gauge after the main filter to make sure I’m getting the 35 psi. I had my tank dipped and lined and it still pushes crap into the filter I added by the tank.
You’re going to have to work through the system and start eliminating items one by one.
-spark at coil
-spark at plugs
-injectors getting power
-fuel getting to injectors
If all that’s good then more diagnostics are required. Like is your ECU working normally.

This is a brand new filter.



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1983 Datsun 280zx
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Discussion Starter · #3 ·
@Av8ferg is that picture of the line with sediment downstream of your main fuel filter in the engine bay?

I was able to get it to almost start by pumping the gas peddle a bit. I had to go to work, so i left it in my driveway :// blocking the sidewalk...

When i return this afternoon I think ill start by just spraying some starter fluid near the intake and see if that does the trick. if so then its a fuel issue. gut tells me maybe it the fuel pump? I'm just doubting its the spark, but i;ve been wrong before.

Hopefully, the little old lady (105#) can help me push it back into the garage (downhill) so I can work under some shelter
 

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Well, the cold start injector is supposed to add fuel for the assist start and with it being so cold (at least where I am) you might need that for a clean start.

The fuel pump is easy to test.
1. Pull the spade connector on the starter motor.
2. Disconnect power to the fuel injectors by disconnecting the positive wire on the battery. Not the main power on battery but you should have a fusible link connector coming off the battery terminal. That the injector power.
3. Turn the key to start and you should be able to hear the pump running.

If it’s not then it’s either the pump of the fuel pump relay under the drainers side dash or it could be a bad ignition switch.

To answer your question, no this is a filter I installed on a line before the pump. This is to keep from destroying my fuel pump.


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1983 Datsun 280zx
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Discussion Starter · #6 ·
@Av8ferg Its about 46F and rainy here, but Its kept in a garage overnight.

I do hear the fuel pump turn on for about 5 seconds when the key moves to the on position. I'm not super familiar with this car yet so sounds like I need to get it down into the garage to figure this out. Pretty sure the previous owner had it sitting for quite some time before selling.

Where did you pick up the pre-pump fuel filter? May want to invest in that.
 

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Yes, they are for The most part only difference is the ECU PIN numbers if your trying to do the troubleshooting continuity tests. The components are the same.


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Discussion Starter · #11 ·
Here's a couple of the most recent receipts so maybe the can help diagnose some issues. From the paperwork it looks like it sat for a while and then this was the last thing to happen and these were a bit spaced out in time, but semi close in milages. High milage vehicle as you can see at over 280k mi
 

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1983 280ZX Turbo
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The first receipt isn't recent, it's dated 2013. What was the date for the second one?

I reserve judgment as to why a knock would only become audible after the engine ran smoother, but that's definitely something to be aware of and check on. Has it been running without a knock since 2013? Or has it been parked? That isn't clear to me.

Fuel seems more likely than spark, since it was running.
 

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1983 Datsun 280zx
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Discussion Starter · #14 ·
There's about 300 miles between 2013 and the 2016 and maybe a thousand more miles since then. Mostly sitting. I put about 250-300 miles on it since I picked it up. It stopped similar to this after the first day, but it turned right back over and chugged down the street.

Not really sure what the h/l relay is and the oil pressure sw. There's a digital converter assembly mentioned in the receipt that I must not have uploaded. It sure what that is either. I'll attach that too when I got back to the documents.

I sprayed some starter fluid in the gap of the air filter and it didn't turn over when I got back from work. Had a couple guys on the street help me roll it down into the garage before it got dark today.
 

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I’m thinking fuel and here’s why. You problem is intermittent. Spark problems are usually binary. Works it doesn’t work. If you have contamination in the fuel lines or filter the car will run until the pressure in the line creates a blockage. When the car is off and sits the pressure drops and the clogs backs off. This repeats its self until the clog is cleaned out. This is where I’d put my time.


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Hello, it's probably a clogged fuel line, you probably poured fuel with a muck and that's what happened, unfortunately now you also need to clean the entire tank so that it will not be again later and the filters also change all fuel
 

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1983 Datsun 280zx
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Discussion Starter · #17 ·
I'm not sure its the fuel, I did spray starter fluid in the air intake and it didnt start up even for a little bit and i can still hear the fuel pump start when I turn the key.

I did call up the previous "mechanic" from the last two invoices and he said that when he got the car he diagnosed a no start that was resolved by replacing with an oriely distributor. He sounded like he was a family friend that knew a little and probably did "ok" work. I'm thinking he lost some of the trim pieces, jimmied up the power steering pump bolt with vice grips, etc..


I'm going to try some stuff today to see if i can diagnose the no spark and report back. Wish me luck.
 

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1983 Datsun 280zx
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Discussion Starter · #18 ·
I have tried two things to help diagnose if its a spark or a fuel problem and I am at a loss.
-I have sprayed starter fluid in the air intake then cranked over but it never started up. (spray inserted where i pointed to in the image below)
-I took the spark plug lead wire and attached a spare spark plug to it and grounded to the neg battery terminal. I was able to observe spark, but not sure if its frequent enough (first time testing). I attached a video link for you tube.


Now, as far as I can tell I have spark, and fuel addition to the air intake doesn't correct the no start. Is there something else I should eliminate or something else I should try to confirm my findings already?



Motor vehicle Hood Vehicle Automotive design Automotive air manifold
Motor vehicle Automotive tire Hood Automotive fuel system Automotive design


 

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1983 280zx n/a 5-speed t-tops
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Only thing left is AIR if fire and fuel are present. Check the air flow meter to ensure it operates smoothly an is not jammed. Same for the throttle body.

On the outside chance - ensure you haven't broken or slipped your timing chain, or that your valves aren't so loose they don't provide enough flow. Can either remove the timing cover inspection port on front of engine to watch timing chain rotate, or remove valve cover to inspect cam, chain an valves from above.

Or, your distributor timing has drifted so far off it isn't functional. Check if distributor lock screw is tight. You can check distributor timing with a timing light while cranking.
 

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Discussion Starter · #20 · (Edited)
Wow,

I finally found it today. I went through methodically the fuel system, spark system, air, and then I was checking the compression of the cylinders before moving to the timing. In disconnecting the ignition system to check compression, i found it... there was a loose screw on the ignition coil that connects it to power. It was able to provide a consistent spark to each wire, but must of acted wonky when it would start to catch or move. I secured it and fired right up...

With that being said I'm going to continue to check out the timing inspection hole you talked about and will likely remove the valve cover soon, probably will refinish it with some paint and cleaning.

Has anyone used the compression tester gauge before? looking at the instructions, it says to do on a warm engine and rotate the chamber 3-4 times by turning the key. I had to turn it quite a bit more to reach higher pressure (90psi). Is there a usual psi of these Zs or anything i should know about these tools/practice?
 
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