I hate to ask…J13 suddenly not running.

[pidge]

Guys and gals, I’m in need of some help here. I’d rather diagnose and hopefully fix the problem for myself and others down the road than send it off and not gain some insight and knowledge of how things work……Can I give the Coles Notes. The truck will start and idle with the choke fully out. It dose sputter more than usual. In the last two weeks I’ve replaced the lower rad hose, which involved me removing the rad and flushing it out with a garden hose. Replacing the oil filter and oil with Shell Rotella T4 10W-30. Replacing the fuel filter which I cut about 3/4” off the line due to it looking bad on the outside of the line itself. Removed the air cleaner assembly to help a fella and put back air cleaner assembly. I pulled the plugs yesterday morning after work to check them and they were sooted pretty bad. I cleaned them, reinstalled them and there was no difference in idle. (Still stalling when choke is off) I’ll admit I know when to ask for help, but I hate it. I’ve looked at a bunch of posts and don’t no where to start after what I’ve already done. I’ve messed around and done a few clutches in my life u joints and a bunch of things I probably shouldn’t. I’m questioning the fuel filter. The ones I e got in the past were cloudy plastic and the new one is see thru. I don’t know if it’s a different supplier, but what I can tell is the fuel level doesn’t change wether at run or sitting. I don’t know if this is a hint or not. Speaking of fuel I use Shell highest octane in both my trucks. Up until reinstalling the air cleaner that I previously mentioned it was running okay. It had some fouled plugs that I’d clean and be somewhat good. It always seemed to wanna die or stall if I didn’t let it warm up and idle for 10 minutes. I’m hoping the DATSUN GODS can help direct me and solve this shitty poor idle condition. I have some pics, but I haven’t learned how to down size them since the upgrade to the site. They may come in a few posts just for one or two. 
-Pidge

[pidge]

[pidge]

[pidge]

[pidge]

[Crashtd420]

7 minutes ago, pidge said:

Dont worry about this... its normal...

Apparently as the filter gets dirty the level increases to let the fuel through cleaner sections....

I assume the outlet pipe inside the filter is still submerged in fuel....

 

Not sure about your running issues 

[Crashtd420]

Have you ever cleaned the carburetor.... almost sounds like a clogged jet....

[pidge]

I should note….had the alternator worked on a month ago. The voltage reg. was buggered and they added some kinda regulator. Just adding this info as I think about stuff. I don’t think it’s the issue. I’m just throwing it out there. It ran fine or “normal” after that fix. 

[pidge]

2 minutes ago, Crashtd420 said:

Have you ever cleaned the carburetor.... almost sounds like a clogged jet....

I’ve never cleaned it, no. I wish you were my neighbour and have you look at it. I don’t know the history of the carb. I’ve never “cleaned” it. It’s always ran decent. Always also had a bit of a stutter off the hop unless warmed up for 10min or so. 

[Crashtd420]

10 minutes ago, pidge said:

I’ve never cleaned it, no. I wish you were my neighbour and have you look at it. I don’t know the history of the carb. I’ve never “cleaned” it. It’s always ran decent. Always also had a bit of a stutter off the hop unless warmed up for 10min or so. 

Even mine needed a cleaning after about 5 years.... and it was brand new.... mine was caused by the fuel siting over the winter.... 

Does the truck sit for an extended period?

 

[pidge]

Over the winter it is stored. I dont Drive it or start it. I put in the high grade Shell gas and add stabilizer before storage. It’s not a daily driver. It’s a weekend fun for me. It’s not driven far. Max round trip 20 kilometres so the gas dose sit for time I would say. 

[pidge]

44 minutes ago, Crashtd420 said:

Dont worry about this... its normal...

Apparently as the filter gets dirty the level increases to let the fuel through cleaner sections....

I assume the outlet pipe inside the filter is still submerged in fuel....

 

Not sure about your running issues 

I understand what you’re saying. Thank you. 

[Crashtd420]

15 minutes ago, pidge said:

Over the winter it is stored. I dont Drive it or start it. I put in the high grade Shell gas and add stabilizer before storage. It’s not a daily driver. It’s a weekend fun for me. It’s not driven far. Max round trip 20 kilometres so the gas dose sit for time I would say. 

I think what happens is the gas in the carburetor dries up leaving little bits behind... 

 

I still am leaning towards you need to clean the carburetor.... 

Weekend driving should be good but I suspect winter storage is the cause, even with the fuel treatment.

Can you get at the jets easily? Might be able to check them without messing with to much....

 

Maybe try to drain the carburetor before storage in the future....

 

I once had a small (nat) bug clog a main jet on my atv.... so it doesn't take much....

 

[Stoffregen Motorsports]

Simplest explanation for sudden death would be related to work you just performed.

 

Aside from that, it sounds like it's in the carb.

 

Clarification - it does or does not run?

[datzenmike]

 

 

 

 

Only runs with choke on? The choke forces a rich mixture condition so if richer makes it run it can be assumed that without the choke the mixture is way too lean.

 

1/ Look for a vacuum hose connected to the intake. Most likely the one to the ATC (auto temp control) servo on the air filter snorkel. Probably pulled off when the air filter taken off. My hose is too short and always pulls off when I take the air filter off.

 

 

2/ Idle has it's own fuel supply and is separate from the primary and secondary barrels so a clogged jet, at this point, is unlikely. Find the mixture screw and unscrew it, counting the turns so it can be put back in in the same place. Get a can of carb cleaner or WD-40 that has a straw for directing the spray and put in the idle mixture hole and spray it out. This should dislodge any debris blocking fuel flow into the idle circuit. See if this helps.

[mainer311]

Nikki carb? I can't remember, but do they have an idle jet that controls a transition circuit like the Webers? If so, it's definitely that one that's causing the problem. 

Edited July 27, 2023 by mainer311

[pidge]

14 hours ago, Crashtd420 said:

Have you ever cleaned the carburetor.... almost sounds like a clogged jet....

No I’ve never cleaned it nor do I know if it’s ever been cleaned. 

[pidge]

11 hours ago, Stoffregen Motorsports said:

Simplest explanation for sudden death would be related to work you just performed.

 

Aside from that, it sounds like it's in the carb.

 

Clarification - it does or does not run?

I was thinking the same, but going over everything I can’t come to a conclusion. It starts with choke out, butIt barely idles after about 10 seconds and with the choke in it starts to shake the motor pretty bad and dies out. 

[pidge]

11 hours ago, datzenmike said:

 

 

 

 

Only runs with choke on? The choke forces a rich mixture condition so if richer makes it run it can be assumed that without the choke the mixture is way too lean.

 

1/ Look for a vacuum hose connected to the intake. Most likely the one to the ATC (auto temp control) servo on the air filter snorkel. Probably pulled off when the air filter taken off. My hose is too short and always pulls off when I take the air filter off.

 

 

2/ Idle has it's own fuel supply and is separate from the primary and secondary barrels so a clogged jet, at this point, is unlikely. Find the mixture screw and unscrew it, counting the turns so it can be put back in in the same place. Get a can of carb cleaner or WD-40 that has a straw for directing the spray and put in the idle mixture hole and spray it out. This should dislodge any debris blocking fuel flow into the idle circuit. See if this helps.

I’ve never noticed any hoses coming off the carb or air filter housing, but I’ll take the housing back off and have a look again when I get in, in the morning. I’ll have to look at a previous drawing and look for that idle screw. 

[datzenmike]

The J13 was earlier but later 521s had a vacuum powered servo that closed to draw warmed air from the exhaust manifold. I've seen earlier ones that were manually opened or closed marked summer or winter. This may be the case here.

 

 

Below. The air filter snorkel does have the connection on the under side for the 'stove pipe' connecting to the hot exhaust. The stove pipe is missing though.

[pidge]

It’s there just disconnected from the air filter side when pic was taken. 

[Stoffregen Motorsports]

Starts with choke but then dies indicates fuel flow. Since there is fuel in the filter, it's probably a blockage inside the carb. Have you disconnected the hose at the filter while cranking to see if fuel flows from the hose?

[pidge]

“Idle has it's own fuel supply and is separate from the primary and secondary barrels so a clogged jet, at this point, is unlikely. Find the mixture screw and unscrew it, counting the turns so it can be put back in in the same place. Get a can of carb cleaner or WD-40 that has a straw for directing the spray and put in the idle mixture hole and spray it out. This should dislodge any debris blocking fuel flow into the idle circuit. See if this helps”

 

I believe it’s the one in the pic I did remove and spray carb cleaner in the hole and cleaned the pointy piece. Took about 12-1/2 turns to come out. Still the same thing. I gave the carb a few shots right down the top as well. 

 

 

 

 

Edited July 30, 2023 by pidge