Can anyone tell me what brakes these are?

[banzai510(hainz)]

To me it looks like a fuel pump. So be careful if that is a power wire going to it and see if has power when the key is ON. Or hopefully when the key is on. Just make sure its OFF if you pull this out.

 

Now you say in 4th you loosing power but 1 thru 3 seems fine?

To me I would look at the distributor.

Is it timed ?  and make sure the dist advance plate moves.

 

Has this motor been OK before or is this a recent event?

[ShaneLovesDatsuns]

Ok I feel totally stupid, it's my distributor and it definitely needs timing done. It did the diesel sputter when you turn it off like timing I'd jacked. Stupid on my part. My apologies. And as for the power wire I'm going to test it when the weather clears up. And to top it all off I blew up my clutch on a hill start leaving work today.... Fun times haha how much would it cost me to take her in and have the valves done and get it timed? I have a little knowledge and I know my way around a wrench but this intimidates me.

[datzenmike]

Not understanding you.

 

So you found the problem and it's fixed now? Or guessing? Run on or dieseling has little to do with the distributor. It only definitely needs the timing set if you check it with a light. You can't tell much by looking at it. 

 

What happens if you go slowly up through the gears to 50 and then give it the gas??? If the timing was causing this it would affect the other gears too. Try slower and see what happens. If it improves the 50MPH speed limit even temporarily, than your fuel pump is at fault, your carb float is set too high or the fuel filter is plugged. The easiest thing to do is replace any and all fuel filters. 

[ShaneLovesDatsuns]

Replaced filter, and lines. Distributor needs to be changed it's crusty. And it's definitely got bad timing because of the run on. It needs a bit of work I'm aware, and I've tried top rev slowly through the gears as possible but nothing helps. At 50, if you give it more gas slowly until you're to the floor, the rpms never change. I did notice after replacing filter and lines that it ran much more smoothly, however, no increase in top speed. Sorry you misunderstood. But when timing got mentioned, it hit me. It definitely needs timing done and the valves haven't been adjusted for a long time I'm sure. I understand a lot of people will say don't fix what isn't broken, but the PO not having much history on the car, I'm just trying to cover all bases. I also can't really check much else until I get my clutch replaced now.... Total bummer.

[DanielC]

Ignition timing should not have any influence on running on, after the engine ignition is shut off.  No ignition current from the key, no spark.  If there is no spark, the time the spark happens is a moot point.

 

You have to adjust the valves before doing anything else.  Then set ignition timing.  After that then set the idle mixture, and idle speed.  Idle mixture, idle speed, and ignition timing are all interrelated.  When setting the timing, the idle speed has to be below 750, because if the idle speed is higher, centrifugal advance starts coming in, and it becomes impossible to accurately set timing.  If the idle speed is too high, then the distributor starts getting vacuum advance, , and again it is hard to set the timing.  If the timing is too far retarded, you have to open the throttle too much, and transition ports in the carb are exposed, and that makes it hard to set the proper idle mixture.

[DanielC]

The clutch pedal should have a bit of free play, that is right at the top of its travel, the pedal moves freely, and then is harder to move.

Go under the truck, on the right side, and find the slave cylinder for the clutch.  There should be a spring pulling a lever that goes into the bell housing, back toward the slave cylinder.   When you step on the clutch pedal, the cylinder extends, releasing the clutch.  There should also be a little free play in the throw out lever, before it contacts the pressure plate. 

[ShaneLovesDatsuns]

Ok I will check that, however my clutch had been getting worse and worse. Felt like an old worn out clutch. Free play, yes, but all the way to the floor the clutch hardly engages now. I'll get the valves done as soon as I can. And as usual, everyone has different information. So I'm trying to take all of it and find a happy medium with what I find through my own research. So I do apologize if I sound like a COMPLETE clueless jack ass I'm truly trying to figure this all out.

[DanielC]

Download this.

http://www.davidcmurphy.com/olddat/data/Service_Manual_Datsun_Pick-up_Model_521_Series_Chassis_and_Body.pdf

 

And this.

http://www.davidcmurphy.com/olddat/data/Service_Manual_Model_L16_&_L18_Series_Engines.pdf

 

Both of those came from here.

http://www.olddatsuns.com/

[banzai510(hainz)]

bleed the slave cylinder 1st.

 

timming is EZ and a 5 min job with a timming light. ( a must get item with a Datsun).

 

A clutch job is not EZ first time around just do the EZ things 1st

 

Mklotz has a L series valve vid. this is EZ. dont cost nothing.

 

 

this is a EZ fix

 

 

what carb you have on this?

 

 

ez to bypass the elelctric pump to ck also. but time the MOFO first.

If it idles already the mixture is close enough otherwise it wouldnt run.

 

what ths ignition system on this?

[ShaneLovesDatsuns]

bleed the slave cylinder 1st.

 

timming is EZ and a 5 min job with a timming light. ( a must get item with a Datsun).

 

A clutch job is not EZ first time around just do the EZ things 1st

 

Mklotz has a L series valve vid. this is EZ. dont cost nothing.

 

 

this is a EZ fix

 

 

what carb you have on this?

 

 

ez to bypass the elelctric pump to ck also. but time the MOFO first.

If it idles already the mixture is close enough otherwise it wouldnt run.

 

what ths ignition system on this?

 

I would really love to take your advice here but I just moved. And this is My only car. I can't get to work without my clutch. It's my number 1 priority right now. Im not a rich person, by any means so it's hard for me to go out and bit all this crap when I hardly scrape by anyway haha. It's on an old weber carb, it idles beautifully, and ignition system beats me. I don't even know how you would tell a one ignition system from the other. And I've replaced a hundred clutches in friends cars over my life, but I've never messed with valves or timing

[banzai510(hainz)]

I just don't want to find out the clutch is goo cause you didn't bleed the slave cylinder and the system.

 

clutches go out over time and they need adjustment at the lower slave.  Unless just a total disk shear or a major lock up of some sort.

 

The comment all the way to the floor????? to me this is no fluid in the system or air.

 

most clutch when they wear is they slip. in like 4th gear then the lower gears.

 

If this is your only vehicle then your pretty much fucked at these things are nearing 40yrs old and break all the time. Mine does.

 

 

most likely its a point ignition. but photos would help. they need to be gapped also.

[datzenmike]

Run on is caused by enough heat and compression to explode the idle gas and air mixture after the ignition is shut off.

 

 

Causes are:

 

*Abnormally rich mixtures. Choke stuck partly on, idle mixture adjusted too rich, carb flooding, float set too high, wrong carb or more likely too large a jet. Un-burned gas ends up as carbon on plugs and combustion surfaces that glows red hot. All you need is gas and aid and compression to fire the cylinder from the heat.

 

Compression too high for the octane of the gas you are using.

 

Too high a heat range spark plug. Tip becomes glowing hot and becomes an ignition source after the ignition shut off.

Idle set too high

 

Idle cut solenoid not shutting off or parts mission

 

Engine running too hot. Replace thermostat with 175F. Check belts and hoses. Always run a fan shroud. Use 50/50 anti freeze distilled water coolant. Check rad for scale build up. If heater hoses have been looped together because of bad heater core, un-connect and close off the ends or fix heater. 

 

 

 

 

* most likely.

[ShaneLovesDatsuns]

Run on is caused by enough heat and compression to explode the idle gas and air mixture after the ignition is shut off.

 

 

Causes are:

 

*Abnormally rich mixtures. Choke stuck partly on, idle mixture adjusted too rich, carb flooding, float set too high, wrong carb or more likely too large a jet. Un-burned gas ends up as carbon on plugs and combustion surfaces that glows red hot. All you need is gas and aid and compression to fire the cylinder from the heat.

 

Compression too high for the octane of the gas you are using.

 

Too high a heat range spark plug. Tip becomes glowing hot and becomes an ignition source after the ignition shut off.

Idle set too high

 

Idle cut solenoid not shutting off or parts mission

 

Engine running too hot. Replace thermostat with 175F. Check belts and hoses. Always run a fan shroud. Use 50/50 anti freeze distilled water coolant. Check rad for scale build up. If heater hoses have been looped together because of bad heater core, un-connect and close off the ends or fix heater.

 

 

 

 

* most likely.

 

 

Thank you for all of this. I'll do whatever I can. I don't want to be totally screwed here at all. I'm confident I will get the issue fixed eventually, as for my clutch, adjusting seemed to do the trick. Now I will try to find somebody to help me do valves and timing, I'll get the distributor and wires checked out, change every fluid I can and do whatever possible to keep it happy. This truck means a shit load to me. Thanks guys.

[datzenmike]

On the clutch... you must have a small amount of play or looseness at the push rod and at the pedal. Push down on the pedal with your thumb. It should move a few mm maybe 1/16" before becoming firmer. The danger is having it too tight and the release bearing is wearing against the spinning clutch all the time.