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Datsuns are for ladies.


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Hope that caught your attention.

 

Hi, name's rachel. I picked this up a couple months ago:

 

407078_3163697368300_1141320533_3360678_1520942463_n.jpg

 

It's an 86 Nissan 720 (the title says Datsun, and stuff) obviously. 121k miles on it, got it for $600 from a guy who didn't have it long enough to even switch the title into his name, because he gave up on it. He bought it from the original owner, btw. I also have a two tone 89 Nissan 240sx, but who cares about that! Onto fun truck things...

 

I have replaced:

plugs

wires

dizzy cap

alternator belt

ENTIRE carburetor. (the original had too many broken pieces, and was just a mess)

 

The guy I bought it from said he had the battery and the alternator replaced (Both seem new, so i suppose he isn't lying)

 

I still need to replace the fuel filter, and change the oil, and small things like that.

 

But the immediate problem (which is why I am incredibly excited to have found this forum, I hope) is that it will drive for a little bit, then randomly die, then start back up after a few minutes, drive a little bit, then die again, and then repeat the process.

 

Number one thing that i think is causing this 'starvation for fuel' (as some have suggested) is probably the fuel filter. But if this doesn't fix the problem, I don't want to go through the process of throwing more and more parts at it (like a fuel pump).

 

So, my question is, what other suggestions can anyone give me?

 

And hello!

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I had a similar issue. Turned out to be the fuel pump relay. When it dies, leave the key on and goto the passenger side. See if you can hear the fuel pump going still.

 

If not, PM me and ill show you how I fixed that. Pretty simple. Might be something else though. My method costs about 5 dollars VS the 70 dollar "special" relay. And its setup so if I wanted to throw the stock relay back in you can.

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Hi Rachel, I'm so glad you found us here welcome to Ratsun. The late 720s if built after April '85 have Throttle Body fuel Injection and the easiest way to tell is if the air filter has two wing nuts holding it on. The TBI will have a small electronics box, or ECU under the driver's seat that can store fault codes that can be retrieved by the owner. This could be invaluable for trouble shooting the problem. The procedure is...

 

 

1/ warm the engine thoroughly.

2/ check that the diagnostic mode selector switch on the box is set to OFF

3/ Turn ignition switch to ON (don't start)

4/ Check that both the RED and the GREEN indicator lamps are now ON

5/ Turn diagnostic mode selector switch to ON

6/ The RED lamp indicates tens and the GREEN lamp indicates units. It should flash 2 reds and 3 greens (a code 23) followed by a code 24 (2 reds and 4 greens)

 

If any other code is displayed, write this down.

 

7/ Depress accelerator and release

8/ Check that only a code 24 is displayed

9/ Depress clutch and shift into 4th or 5th, remove shifter to neutral and release clutch.

10/ Check that only code 44 is displaying.

 

If any other code is displayed, write this down.

 

11/Turn diagnostic mode selector to OFF

 

You are done.

 

 

Fault codes

 

11 Crank angle sensor (CAS)

12 Air flow meter

13 Water temp sensor

21 Ignition signal

23 Neutral & clutch switch

24 Neutral & clutch switch

32 Start signal

42 Throttle sensor

43 Injector

44 All diagnostic sensors OK

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I had a similar issue. Turned out to be the fuel pump relay. When it dies, leave the key on and goto the passenger side. See if you can hear the fuel pump going still.

 

If not, PM me and ill show you how I fixed that. Pretty simple. Might be something else though. My method costs about 5 dollars VS the 70 dollar "special" relay. And its setup so if I wanted to throw the stock relay back in you can.

 

 

I forgot to add that I replaced the fuel pump relay as well. So, If not the fuel filter, maybe something is wrong with wiring?

 

 

Does the sputter and die like you ran out of gas or does it just shut off?

 

It sputters like it is running out of gas, yes actually.

 

 

Hi Rachel, I'm so glad you found us here welcome to Ratsun. The late 720s if built after April '85 have Throttle Body fuel Injection and the easiest way to tell is if the air filter has two wing nuts holding it on. The TBI will have a small electronics box, or ECU under the driver's seat that can store fault codes that can be retrieved by the owner. This could be invaluable for trouble shooting the problem. The procedure is...

 

 

1/ warm the engine thoroughly.

2/ check that the diagnostic mode selector switch on the box is set to OFF

3/ Turn ignition switch to ON (don't start)

4/ Check that both the RED and the GREEN indicator lamps are now ON

5/ Turn diagnostic mode selector switch to ON

6/ The RED lamp indicates tens and the GREEN lamp indicates units. It should flash 2 reds and 3 greens (a code 23) followed by a code 24 (2 reds and 4 greens)

 

If any other code is displayed, write this down.

 

7/ Depress accelerator and release

8/ Check that only a code 24 is displayed

9/ Depress clutch and shift into 4th or 5th, remove shifter to neutral and release clutch.

10/ Check that only code 44 is displaying.

 

If any other code is displayed, write this down.

 

11/Turn diagnostic mode selector to OFF

 

You are done.

 

 

Fault codes

 

11 Crank angle sensor (CAS)

12 Air flow meter

13 Water temp sensor

21 Ignition signal

23 Neutral & clutch switch

24 Neutral & clutch switch

32 Start signal

42 Throttle sensor

43 Injector

44 All diagnostic sensors OK

 

 

 

Will all of this ^ neat stuff still work if the truck is an auto?

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My relay was replaced, worked fine for a few and did it again. Turned out to be the stock wiring. Dunno where at, or what. But after I put in a diff relay and wired it in, haven't had an issue since. It was at random it would quit. Come out the next day, it'd be working again.

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Welcome! I also paid $600 for my truck from a guy who didn't have it long enough to title it! My truck didn't have fuel issues, it had heater core issues though. If'n you have the patience, check out my thread, http://community.ratsun.net/topic/40035-newish-720-owner-here/ and you can see where I've gone from about where you are now. Warning: lots of pictures.

 

Now, if the fuel filter doesn't fix your problem, and you have a multimeter, I can walk you through some troubleshooting steps.

 

Also, if you ever come through Nashville, I have a blue dash you can have. You can see that in my thread too.

 

Good luck!

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Welcome! I also paid $600 for my truck from a guy who didn't have it long enough to title it! My truck didn't have fuel issues, it had heater core issues though. If'n you have the patience, check out my thread, http://community.rat...720-owner-here/ and you can see where I've gone from about where you are now. Warning: lots of pictures.

 

Now, if the fuel filter doesn't fix your problem, and you have a multimeter, I can walk you through some troubleshooting steps.

 

Also, if you ever come through Nashville, I have a blue dash you can have. You can see that in my thread too.

 

Good luck!

As did I!!!! $600!!!

 

I think thats the going rate for a 720!!!!

 

LOL...

 

only difference is... my guy had his from 2004-2009 when I bought it BUT it was a lien sale he made from a tow yard and never bothered to reg it, just let it sit on his property with like the other 50 cars he has that dont ever move... made it just as much to pay back registration as it cost me to buy the Truck!

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Welcome! I also paid $600 for my truck from a guy who didn't have it long enough to title it! My truck didn't have fuel issues, it had heater core issues though. If'n you have the patience, check out my thread, http://community.rat...720-owner-here/ and you can see where I've gone from about where you are now. Warning: lots of pictures.

 

Now, if the fuel filter doesn't fix your problem, and you have a multimeter, I can walk you through some troubleshooting steps.

 

Also, if you ever come through Nashville, I have a blue dash you can have. You can see that in my thread too.

 

Good luck!

 

Actually, I think I saw your thread on NICO and saw something about ratsun, so I came here and voila! Your entire build thread made me realize how much work these little guys are, but definitely gave me some ideas for fixing mine up. So, thanks for that!!

 

Going to replace the fuel filter today, everyone cross your fingers that it works!

 

 

And funny how everyone seems to get theirs for $600...

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ha!! got mine for $300!!! :) half-off!!! but there was a lot of bargaining and waiting to make sure no one else bought it... It was mine from the get go, guy just didnt know it then... :)

 

You should check your carb adjustments. said you got a new one... mine did this to me the other day, but i removed the altitude compensator and drove it up into the mountains. easy fix for me was to raise the idle a little. from 800rpm to 1000 and that fixed it for me.

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dont forget the filter in the fuel pump itself. that was my starvation issue. you can just take it out and spray it off with carb cleaner. thats what i did, worked like a charm

 

 

i got both of mine for 600 combined :P

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OK! replaced the fuel filter that is outside of the pump (supposedly there are two though..? not sure about that, if anyone knows do tell!) It started right up, of course. But then the pump would only prime occassionally, and then stop working. So we've narrowed it down to the fact that it must be the pump, since it was acting so oddly. So looks like someone is ordering more stuff from rock auto!

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Yes, on 9/ substitute for automatic: Shift from PARK to any other gear and replace in PARK

 

Also, mine's defintiely NOT TBI, so I would need to know how to adjust the carb, where to start and such. If you can help with that, it would be greatly appreciated! :) You guys are the best!

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OK there are two kinds of carb on the 720s. Take a look at your exhaust manifold... does it have an O2 sensor on it?

 

 

Does it look like the one on the left or does it have an O2 sensor with a wire on it near the bottom like the one on the right?

exhaustmanz24andz24iLarge.jpg

 

 

Also there is an electrical connector on the back of the carb... how many wires are there? 2 or more??

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OK there are two kinds of carb on the 720s. Take a look at your exhaust manifold... does it have an O2 sensor on it?

 

 

Does it look like the one on the left or does it have an O2 sensor with a wire on it near the bottom like the one on the right?

exhaustmanz24andz24iLarge.jpg

 

 

Also there is an electrical connector on the back of the carb... how many wires are there? 2 or more??

sorry to interject... mike... can you tell me the mm size of the diameter of those two fittings on the front of the right manifold? The ones where the air injection tubes connect... are they 22 or 24?
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the 2nd filter is INSIDE the pump, and if its clogged, the pump cannot push volume

 

here is what it looks like, pictures taken of mine when my truck did the same thing.

 

1325559682.jpg

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OK there are two kinds of carb on the 720s. Take a look at your exhaust manifold... does it have an O2 sensor on it?

 

 

Does it look like the one on the left or does it have an O2 sensor with a wire on it near the bottom like the one on the right?

exhaustmanz24andz24iLarge.jpg

 

 

Also there is an electrical connector on the back of the carb... how many wires are there? 2 or more??

 

 

I believe it's the one on the right because it has that shield thing and the O2 sensor (I won't be near the truck for the next couple days) and I THINK the electrical connector has 5 wires...

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I believe it's the one on the right because it has that shield thing and the O2 sensor (I won't be near the truck for the next couple days) and I THINK the electrical connector has 5 wires...

 

That makes it the electronic feed back carb. (not good as this is a crossover between carburetor and fuel injection) These are notorious for having a loose or broken wire inside the insulation because the leads are too short. This causes the wires to kink too much and break inside causing all manner of intermittent hard to find problems.

 

One of the wires is the idle cut solenoid (anti dieseling solenoid) which must remain ON when running or there is no fuel allowed to the idle circuit and it will not idle. Turn the ignition to ON / OFF / ON / OFF (don't start) while listening near the carb. You should hear a light clicking sound if working. With the key ON, wiggle the connector and the wires. If the wire is loose or broken there will be clicking sounds as it makes intermittent contact.

 

Another is the throttle valve switch. This tells the ECU that you are off idle. If not working the ECU will be fooled into thinking you are decelerating all the time and can shut the idle cut solenoid off.

 

Air fuel ratio solenoid inoperative. Engine will revert to an over rich 'limp home mode' .

 

 

 

 

 

 

ECCelectrocarbZ24engine.jpg

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