Engine dies randomly

[datzenmike]

 The second set of points are adjusted so they open about 4 degrees after the first set. When on, the timing is retarded or fires later by 4 degrees. Not enough to affect anything and after all it is designed to run properly in the 'retarded' position. It's a complicated set of of switches (carburetor, transmission ((only in 3rd)), throttle and a temperature sensor that only allows it to work above 10F) and you replaced the carburetor so that switch is missing so it can't be on.

 

There will be a small relay very near the coil. If you want, unplug it and the distributor will remain in the advanced position only.

 

 

Did you check for spark when engine not starting? Be a shame to chase carburetor or fuel pump delivery only to find there's no spark.

 

 

 

 

 

[Logical1]

Does your weber have an idle cut solenoid? 90% of engines that die with webers have been an issue with the idle cut solenoid. 

[Driver915]

Good to know about the 2 points setup and that it's working "properly" for the carb I have. Will still look into a single points distributor though. I checked for spark when it died and it had spark, it fired up and idled on 3 cyls. So that isn't the problem unless it somehow fixed itself within maybe 15 seconds. To the guy above Mike I ran it off a can for a couple weeks while working on other parts of the motor and it ran fine, if I chase the lines and something seems off between the tank and pump I'll try rigging a can up and cruising around like that for awhile. I'm wondering if something lodged itself in one of the filters causing a block that I can't see. I do have two filters on the truck I added one coming off the tank plus the original in the engine bay. If I mess with the fuel system and it still does it I'll keep checking the spark side. As far as I'm aware no it does not. It's a 32/36 DGV manual choke. I was reading only the electric choke models have that idle cut solenoid. Correct me if I'm wrong. There's no electrical to the carb, just throttle, choke, fuel and vacuum advance.

[thisismatt]

On my 521 the filler neck rubber was deteriorating and dropping bits of old rubber into the tank, constantly clogging the filter(s).

[datzenmike]

Well you could just remove the second set but I don't think dual points are any problem.

 

 

[mklotz70]

The manual explains how the 2nd set of points work.  As Mike said....they're not the issue.  They only get put in the circuit in 3rd gear under certain conditions....such as temp.....and I'm pretty sure it's only during deceleration.  The first set is working, so whether the 2nd set does or not, it's moot.  As suggested, just remove them...but I'm sure they're never being "added" to the circuit.  If you're still worried about it, just remove the wire on the outside of the dizzy....the one that feeds the second set.  Once disconnected, you will have a single point dizzy, so the only reason to find a "single point" dizzy would be to put a Pertronix unit in it.  I know Hainz loves them, but I've never been a big fan.  The matchbox dizzy is bullet proof if your dizzy is correctly grounded.  I seriously doubt the dizzy is your problem but switching to EI after you have this issue resolved is a great upgrade. 

 

Since the pump seemed weak, that may indicate that you have a blockage between it and the tank....it's being starved, so it can't pump enough fuel.  The filler neck tube flaking into the tank is a good point.  Running it off a gas can for a few days is also a good suggestion.  If the issue is resolved with by running off the can, your issue is probably in the tank.....at least somewhere prior to the fuel pump.  If it still does it, I'd look at the carb.  The idea that maybe the float valves is sticking is a valid point.....especially if the fuel pump isn't pushing well.  Keep in mind....the Weber only wants about 3psi compared to the 7psi the stock pump puts out.  You can get a fuel pump pressure regulator to put between the pump and the carb, but not many people do.  The extra pressure would be more apt to cause a flooding issue, so it's not something worth doing at this time.  

[mainer311]

Take the fuel hose off of the pump inlet, take the gas cap off, then used compressed air to blow out the lines between the pump and tank.

[Driver915]

I just went through and blew out the lines between pump and carburetor and there's way more fuel coming out of the pump than the line going into the carburetor, even after blowing through. When blowing it out nothing seemed out of the ordinary and plenty of air was making it through. I suppose it could be over fueling it but the first two times it died the main bowl was bone dry upon first inspection. One problem I had with this fuel pump the moment I got it was the ports are all 3/8" instead of 1/4" like the truck had. The carburetor is the same way, 3/8" port. Would it be worth a try to run a 3/8" line from the pump to the carb and see if it has more/less issues? Or is it better to have the smaller line acting as a regulator? And I will try blowing out the tank and lines again to see if anything's clogged there. I added a filter coming off the tank so I'll disconnect that and split it between blowing the main lines and blowing the pickup tube/tank once I have a hand.

[datzenmike]

It's better to have metal lines where possible. Nothing to do with regulation that's set by the pump. It's about being armored against damage and they don't wear out.

 

So if the carburetor was dry then it's a fuel delivery problem. If pump was changed where's the old one and why was it replaced? Do you have the old one?

 

Never throw old parts away.

[Driver915]

Yeah I'm aware of the metal lines thing I'd probably replace it with all metal lines if I could. Was just curious if it was worth it to test it with a bigger line for a moment and if it's better try and figure out how to upgrade the metal to bigger lines too.

The old pump wouldn't work. I still have it, it still doesn't pump. It was basically locked up when I pulled it off the engine, after a little bit of working it the arm started moving but wouldn't move any liquid. That's why it was replaced. The only part that was actually working that I replaced was the alternator, because I put the integrated regulator alternator off a 620 on it. I kept the original alternator and also a new one without the regulator in case at some point I decide to go back to the original setup. Though both the original voltage regulator and aftermarket one are dead. I also have both of those still.

EDIT: To test the old pump I had a fuel line stuck in a small gas can and was just using my hand to get it to move. Nothing came out of it. That's how I determined it wasn't working.

[datzenmike]

The original pumps are pretty bulletproof. Might be worth swapping it back on now that you freed it up. The engine running will work the arm 6 times a second, much faster than by hand.

 

My 710 came with one of those crappy replacement ones on it. I found the original in the back and put it back on. It's been working now for over 12 years.

[banzai510(hainz)]

On 8/26/2023 at 8:40 PM, Driver915 said:

it fired up and idled on 3 cyls

this is not fuel related!!!!!!!!!!

 

like I said earlier unplugg the 2nd set of points(the one with the smaller condensor that will eliminate that thought of bething that

 

Gas line  size is fine.

 

 

Is coil HOT????? maybe you put a wrong coil in ther eand its COOKING!!!!!!!!!!!! But uasullay you pouints would have been FRIED by now.

 

I really dont believe a Brand new Weber is the issuale unless you didnbt change the fuel filter and alot of dirt got in there.

 

the cig lighter VOLT Meter is to watch it while driving so you can detect a upcoming failure. 90% of the time you can spot off before your on the side of the road.  Like no charge when lights heater on . then you can make it home or to garage

Edited August 28, 2023 by banzai510(hainz)

[Driver915]

I think you missed what I said in that post. It fired up and idled on 3 cyls because I had one of the plug wires disconnected with a random plug sparking against the block (to check spark). Put it back on the plug in the block and it ran normal. The coil is the original one I haven't replaced it and doesn't seem to be getting hot. It's about the same temp as anything else along the fender. Warm to the touch sure, but not enough to burn and not hotter then anything else there. I'll unplug the 2nd set of points just to make sure that doesn't cause a problem. It's never ran on 3 cylinders unless a wire is unplugged. Even cold starting it runs on all 4. Mike I'll test that original pump but I dunno it seemed really weak to me. I suppose I can work it a little more and see if it comes back to life. Everyone here says those pumps are invincible so I suppose it may be worth a try. Was barely moving fuel though. Just a few drops every time I pushed the arm. Not even a small stream.

Also does anybody have a part number for the single point distributor for an L16? I wanna try and upgrade this to electronic ignition just to avoid more trouble in the future, and hopefully fix this issue if it really is spark related. Just seems like a damn small chance that it is ignition related.

[datzenmike]

Just remove the second set of points and the condenser (capacitor) and you have yourself a single point distributor. It's not the points.

 

If the carburetor was empty that's the problem not the distributor.  It's fuel delivery. Try the old pump if it's still bad replace the pump.

[banzai510(hainz)]

2 hours ago, Driver915 said:

Was barely moving fuel though. Just a few drops every time I pushed the arm.

it should shoot a stream of gas when you cycle it. the accel pump will squirt gas from the top of the carb 

[Driver915]

Yes it should pump a stream. Hence why I replaced it. I was talking about the original pump and why it wasn't on the truck, the new pump does a stream. Mike I wanted to know the single point distributor part# to put a Pertronix kit on it unless that kit can fit a double, I was under the impression it only fits single point distributors? I found a few single points on eBay but none of them say what they fit, just a part#.

Well guys I may have fixed it. I pulled both filters off, blew the fuel out and they had dirt in them. Blew out the lines between the pump and tank and found some bad gas as well as dirt (put bottle on one end, air compressor on other). I put it all back together with new filters, drained the tank and put 5 gals of fresh gas in it and drove it for probably 45 minutes without issues. Full throttle, light starts, idling, all of it and it seemed fine. Will report back if it dies again. The fuel that came out of the tank looked and smelled ok but it is 1-2 months old and we know how new gas is, goes bad if you look at it wrong. Thank you guys for all your suggestions. Electronic ignition system and non-leaking brakes are next on the list.

[datzenmike]

Yes Pertronix only fits single points distributor shaft. Pertronix gets rid of the points but does not improve the voltage like a true EI distributor.

[Driver915]

Ok that's what I was thinking is that those kits only fit a single point distributor. Is there a good true electronic distributor out there and is it worth it to go for that? I couldn't find any electronic distributors besides random Chinese parts when I was looking and everyone says the Pertronix swap is better than those, even though it still has the cap and rotor on it. Couldn't find anything on a true electronic distributor on a quick search through the forums.

[thisismatt]

Somebody on here is using one of the 123 distributors...

 

https://123ignition.com/product/tune-4-r-v-datsun/

[mainer311]

Crash is. Pricey though.

[datzenmike]

Doesn't Rock Auto or Summett Racing have the after market EI matchbox distributors? Probably Chinese made but if the module fails you can always use a HEI module from a GM.

[Crashtd420]

33 minutes ago, mainer311 said:

Crash is. Pricey though.

Yes and yes..... 

Not worth it for a stock motor....

[Crashtd420]

13 minutes ago, datzenmike said:

Doesn't Rock Auto or Summett Racing have the after market EI matchbox distributors? Probably Chinese made but if the module fails you can always use a HEI module from a GM.

They should.... cant he just get the electronic distributor from another model datsun.... maybe early 620 or the 510...

Probably just need to make sure the the base plate works...

[datzenmike]

Other than California, that messed with some form of magnetic pick up EI a year or two before it was mainstream everywhere else, the '78 L series engines (in the S10, A10, 810 and the 280z) all got the remote igniter. This was replaced the next year, '78,  by the matchbox EI. Which was just a miniaturized remote igniter mounted on the side of the distributor. (A series engines of the same year got the same EIs)  

 

Lots of them were made but the 1980 720 was the last L series matchbox (only made for two years) and the '80 Z20S and Z20E in the A10 and S110 200sx. I've had two from the '80 S110 200sx and they are basically identical to the L series. This is over 40 years ago, where are they now? I sold them off so they could be used.

 

This is not going to solve the running problems but an EI distributor is great to have as there is almost no maintenance. Just replace cap and rotor as needed.