Engine won't turn off, help!

[Janky510]

I just recently did a L20b swap in my 1969 wagon. And everything went fine. Until I went to turn the car off. I removed the key and the engine was still running. I had to put it in gear and pop the clutch to stall the engine. I don't want to keep doing this. What would cause it not to turn off? The L16 I had in it before turned off every time. I probably hooks something up wrong but I have no idea what. Thanks -John

[datzenmike]

Other than the block and head did you swap anything else at the same time.... like the alternator?

[qwik510]

Is this run on where the ignition switch is functioning properly but the car still runs? If so, get the idle down to 650-700 rpms. my L20B tends to run on when the idle is up too high.

[Byron510]

Likely what you have inadvertently done is made a change to the wiring which has the power from the ignition switch, alternator and the ignition system all in line. You can cut power at the key, but the alternator continues to feed power to the ignition. It's likely you have made a wiring change either at the alternator or at the coil/distributor that has caused your issue.

I know I did a similar thing to my 2nd 510, but that was so long ago that I can not remember the circumstances or the repair method.

Hopefully this has helped somewhat. Good luck.

Byron

[andrew.lori]

By now you have probably run out of Gas so your all fixed
Seriously pay attention to what Byron said and ignore me ...

[datzenmike]

Byron, I was thinking an internally regulated alternator mistakenly put into the chassis with a fender mounted external regulator.

[Janky510]

When I took the old engine out, I took pictures of all the wiring that I had to undo, just so I could put it back together right. I have gone over these pictures 5 times and everything is back in the original place it came from. People keep telling me it's the ignition switch. How do I tell if the one I have in there went bad? I have a new one on the way that I got off eBay, but it won't be here anytime soon. And I also used everything that came on the L20b engine. The only things I swapped we're fuel pump, oil pan, and carb. Oh and a new water pump. The engine I put in was supposedly rebuilt 20,000 miles ago, I don't have any reason to not believe that because it doesn't leak or burn oil. I haven't torn into it for fear of screwing something up because this is also my daily driver. And I drive 600 miles a week to work and back home. I don't have a tach so I don't have a way to tell what the rpms are at. Anyways enough rambling. Thanks -John

[dislexicdime]

did you use the alt that was on the l20b? is sounds like you put a internally regulated alt in your car and now the external regulator needs to be unplugged and the wires on the plug jumped i cant remember what wires you have to switch sorry

[okayfine]

He's got a Paologram, the wiring is on there.

[Janky510]

Yes I used the alt that came on the L20b. I don't know hardly anything about it. Idk what alt it is or what. How do I tell?

[okayfine]

Look for numbers. Take pictures of the back. An L20B alt can still be externally-regulated. I don't know the cut-off date for Nissan alts, but IIRC even '78s were ext/reg.

[datzenmike]

'78 Datsuns had internal regulated alternators and will have an LR marked on them. Earlier non regulated ones will say LT on them.

The L16 I had in it before turned off every time.

The easiest thing to do is put the L16 alternator on the L20B motor.

[Janky510]

So today, my voltmeter in my car wouldn't go any lower than 18. And I thought nothing of it, until I got home when I started smellin something funny. I parked and searched for the source, which led me to the battery box in the back. Someone before me relocated the battery to the "cargo area" of my wagon. I looked in the box and there was battery acid everywhere. I thought shit that isn't good. I drove it to the closest o'reilly and had them test the battery. They said it was still good but that it was being overcharged. And after asking the guy what causes that, he told me again basically that its just getting overcharged. And again I asked him what causes it to be overcharged like that, and again he said pretty much the same
Answer worded differently. Then I asked, "What is the source of the reason why my battery is being overcharged!?" then he said the alternator. Finally an answer. So I asked them how much a new alternator was going to be. They couldn't even find one in their computer. I just left after that. The employees at my local o'reilly piss me off sometimes. Yeah I know that the fact they couldn't find an alternator for my car in the computer isn't their fault but it just added to the frustration already building. So I went home and grabbed the alternator that came off my old motor. Swapped them out. I didn't really want to do this because when my old motor was running, the lights always flickered. But I had no other choice. So I put the alternator on and fired it up and my voltmeter said it was kicking out 14 amps or ohms or whatever they're called, which is the number you want to be close to. And then I turned the key to the off position and, not expecting anything, the damn motor shut off! So long story short the guys above were wise in their ways and the alternator was the problem. But the lights still flicker. So I need a new replacement for it, any suggestions? Thanks a lot!!!! -John

[dislexicdime]

look up the hainz video on how to wire in a internal alt and put on the other alt its easy

[datzenmike]

The L16 I had in it before turned off every time.

The easiest thing to do is put the L16 alternator on the L20B motor.

You are frying the battery!!!! Put the old alternator back on!!!!