bad solenoid, ignition switch, ?

[millican]

I've been having starting problems that are getting more common. It will occasionally just click once and that's it. After sitting awhile, it will start up fine. The battery has been checked and was said to be fine. I took the starter out, took the motor apart and cleaned up the contacts with some 600 grit sandpaper. The brushes and commutator were measured with a nice set of calipers and are nearly new. The motor looks pretty clean for that matter. It tests fine on the bench, but it seems a little slower than I'd expect. Then again, it does have a gear reduction. I took this video of starting. The starter fails on the first two tries. The first clicks, the second chatters. The voltage goes back up to 13.8 after it runs a few seconds and a relay switches off.  So, I'm suspecting the solenoid. Most likely, I'm wrong. I had to start it once in Oklahoma recently by letting it roll across a rest area parking lot. It wasn't as easy to do as I'd expected. It has the SD22 engine.

http://darrahmillican.com/~tom/datsun/start.ogv

Here's the voltage while running.

While I had the camera out in the truck, I thought I would ask. What the hell is this choke-looking thing? It doesn't seem to do anything at all.

[datzenmike]

Could be a weak 12 volts TO the starter from the ignition. Take the small wire off the starter solenoid and you can use a wrench to jumper from it to the positive battery cable. Beware that the starter may work only too well, so have the trans out of gear and the brake on for this.

 

If it cranks every time then the signal is weak. If it clicks or chatters then likely the solenoid.

 

 

If a weak starter signal this can be from the long run of wire from the battery to the ignition switch and back out to the solenoid... probably close to 15 feet and many connectors. What you can do is use this weak signal to trigger a small relay that sends a full 12 volts to the starter. My '74 710 was this way with 38 year old small wiring.

[millican]

Thanks King Rat. It must be the solenoid. It didn't go for the last two flips of the switch when I tried it a few minutes ago. I didn't want to use a wrench on a cable attached to the battery with an engine that would move so much, so I used a 45 amp switch instead. Maybe I can change the solenoid without removing the starter? That would be nice. I'll just have to make sure the solenoid rod is on the starter motor lever. At least I don't have to figure out how much current the solenoid needs to get the right relay. It's time for an adult beverage.

 

http://darrahmillican.com/~tom/datsun/start_2.ogv

[wayno]

This is to control the idle when the truck is cold, that cable goes to the top of the gas pedal(diesels have there own pedal), when you pull on it and twist the handle, the idle should go up in rpms, I suppose it could be broken, I could not live without this.

The battery cable going from the battery to the starter is a long one, that cable and the connections on both ends must be good, I found out that if I used a screw driver to start my truck, it started every time, but when I used the key, it would half the time do nothing, or click just once, like when the battery connection is bad, you hit the key and all the lights go out, well it turned out to be a bad connection at the starter, the nut holding the cable on to the starter solenoid was corroded or something, because it started every time when jumping the main cables, so the cables were good, so what I did was tighten the nut a little harder and the starter has worked fine since. 

[millican]

I neglected to mention that I did clean the cables, the connections on the starter, and the battery posts with 600 grit sandpaper as well. The problem persists even when bypassing the starter and using a simple switch (the second video) in place of the ignition. I did find that the starter motor was shorting where the long bolts go through. They are right next to the leads to the brushes and had pits in them. I covered them with a few inches of heat shrink tubing before putting the starter back together. Since I hear that photos are well-liked here:

 

Thanks for identifying the valve. I haven't had this in cold weather yet, so we'll see if it turns out to be useful. I was afraid it was something the previous owner put in randomly. He did a lot of stuff pretty randomly, which wouldn't be so bad if he had at least done those things well. The tailgate that couldn't possibly close, hanging on with a piece of rope tied to one end, severely bent up, was the first thing to go to the recycler.

[wayno]

t's not a valve, it's a cable that goes to the top of the gas pedal that controls the throttle, they crimped two pieces of metal on the end of the cable so it would work only at so high of an idle, otherwise people would have tried to use it as a cruise control down the freeway, that's why it only pulls out just a little ways.

 

You need to check another thing on your starter issues, for some reason the nissan wiring harness starter activation wire can lose voltage, when it drops below a certain voltage the solenoid will not work properly anymore.

You need to pull the wire off the solenoid and stick your voltage tester on that wire and a ground, then turn the key to the start position, does it have full voltage, if it is below 10 volts, it won't work correctly, then what some do is wire in a relay to the starter activation wire post, the original wire then activates a relay that supplies full voltage from the battery to the starter activation wire post on the solenoid, I have seen this on datsun diesels before.

[datzenmike]

.

Ride bicycle much?

[Lee R]

.

Ride bicycle much?

LOL! Or bailed out the chair while getting a tattoo?

[millican]

Haha. Fortunately, a bicycle is my "daily driver". That's a tattoo I had put on a few months ago while my wife was in Thailand. I literally removed the chainring from my bike, cleaned it, and took it to the artist. After my wife returned, it took her two weeks to notice it.

 

That's a good suggestion on checking the voltage drop from the ignition. I'll do that even after trying another starter as a preventative measure if it's as common as you guys say.

 

So it looks like a solenoid costs a bit more than a starter and solenoid. Man, I told my landlord I wouldn't be one of those guys who has a bunch of car parts lying around...

[millican]

LOL! Or bailed out the chair while getting a tattoo?

I actually asked her to make it look like I just put my leg against it a little bit instead of a perfect trace of the ring.

[wayno]

Every time I have ever removed the starter from my engine, it worked fine, it has always been some other issue.

 

I heard that this voltage drop was an issue from someone else, I have had the same issues you described myself, one time it was one of my fusible links gone bad, but other stuff wasn't working either, the diesel wiring harness is a nightmare, to many freaking wires for such a simple engine.

[datzenmike]

Yeah I bike about 8-10 miles round trip a day to work. Rain or shine, snow I don't usually work so it's all good. Thought of a small rear sprocket tattoo. Maybe on an arm? somewhere.

[millican]

A sprocket on the arm would be nice.