Barefootdan

Fixed the valve and it started right up nice and smooth again. Still smoked for a few minutes but it eventually died off...what a relief! Crisis averted👍 Now back to our regularly scheduled build 😄 I was able to get the muffle hooked up which helped tremendously with listening for any strange noises. I'll grab some pictures this afternoon. The last piece preventing a spin around the block is brakes. I was able to start bleeding the front but my driver side bleed screw is clogged. Going to soak it or grab a new one if that fails.

Thats a relief. Thank you. I was jumping to worst case scenarios and didnt even think of the vapors from an open valve. The valve lash of all other cylinders was in spec, so I think it is safe to assume this one was too. I'll keep an eye...or ear 😉 ...out for any strange sounds next time I fire it up. Open headers doesnt make it easy, so that could be my next project in the meantime.

Took off the valve cover and what in the world!!! And intake rocker jumped on #4. Luckily nothing is scored and the retainer was easily found. could this be the culprit? Maybe the fuel was building up in the chamber and steaming off? But this would probably have been black smoke? I’m hopeful but doubtful…other thought is the increase in vacuum was pulling oil through the seals causing the smoke.

Well… the highs are high and the lows are low. Today I changed the oil and retorqued the ARP studs. A few needed about an 1/8th turn to get back into torque but nothing felt odd. 60ftlb per the ARP slip. I ensured I was going in the correct sequence as well. Started up fine and I started to let it warm up. Not even a couple minutes later the idle became strange. Wouldn’t want to rev either. Then the dreaded smoke started coming from the tailpipe. It definitely was not even at operating temp yet. I thought maybe I spilled something and left it at that as I bled the front brakes. I came back to

Hahaha that’s perfect!

A little more detail on yesterday: I started first by draining the fuel tank. The fuel was getting dark, presumably from sitting in the tank for about 6 months, breaking down whatever my cleaning didn't wash out. I was able to pull out about 2 quarts of fuel. From there I headed to the front of the car and drained the fuel rail. I still had 35ish PSI in the line, but cracking open the line I had a nice long hiss of air, followed by a few oz of fuel. So there was definitely a major air pocket up there. New fuel went in, primed the lines, and it started right up 😄 I let the car warm up

I was out of gas….what kind of timing is that! folks just because your fuel pressure gauge shows pressure doesn’t always mean you have enough fuel to run 😉

That’s a good point. I think we’re definitely looking at fuel issue as opposed to timing (since it was running smooth before it died). I had a mini fuel filter (lawn mower style) in before the pump but took it out when I cleaned up my lines. I did notice small sediments in there. The pump is a cheap eBay special and always took about 5-10 seconds to get to full pressure. Perhaps this is just added fuel to the fire. I’ll flush the lines and tank tomorrow when I get new gas. I’ll probably disconnect the line after the fuel filter in the engine bay. I can’t imagine anything substantial

Back from another fire up. I was able to finish the 20 minute break in. So I feel much more comfortable letting the car down below 2K rpm. This time, the car smoked way less, I definitely think the water temp sensor helped. Unfortunately, this time when the car got to temp, I started to bring the idle down to 800, but it was not running smooth. It sounded okay but the engine was definitely not timed correctly or not firing on all 6. I turned it off and inspected my plugs. Dark, presumably from the previous day of running very rich, but nothing seemed wet. From here, I was not able to get the c

I swear I must have jinxed myself...Why would the orange connector go to the grey sensor?! Anyways...30 seconds at the ecu terminal lead me to no readings for the water temp sensor. I saw I chose the wrong connector 😅 Now we have accurate resistance for ambient temp! This is likely my issue but I'll need to wait a couple hours before I fire her up as I am waiting for a gasket to dry. While out there I saw your comment @Zed Head and popped open the TPS cover. I do get contact at idle with the right pin and giving slight throttle moves to the middle. Tested at the ecu terminal to be sure as well

Thanks for that. In my previous post I was referring to the wrong sensor. Water Temperature Sensor (which you referenced) is on the bottom right of the front housing, and controls fuel amount. I was looking at the Water Temperature Switch which is timing advance/retarded related. Lastly, the Thermotime Switch drive the Cold Start Valve. Now that I am all cleared up (thank you Datsun for the naming conventions 😄)... What I have in my car, hooked up, is the Water Temperature Sensor. I do not have a Thermotime or Water Temperature Switch. I dont have a cold start valve, so scrap the termoti

That seems like the logical case. Ran fine until it warmed up and then it caused issues. I’ll wait to continue the remaining break in until I get that sensor plugged in 🙂 now I know there’s two temp coolant sensors. One is for the cold start valve, the other is for the fuel mixture (or length of time the injector is open). Are we both referring to the same one, the latter? I think it is on the driver side of the thermostat housing, as opposed to the front of the housing.

Pulled out the Z today to break in the motor! Started right up and brought her right above 2000 rpm. She lasted about 8 minutes before I realized I didn’t hook up my radiator fans. So I turn it off and hooked those bad boys up just temporarily. Started again and continued to break in. Temp was holding in the middle of the gauge nicely! I had a vacuum leak still so keeping the idle steady was a handful. It ultimately died as I was checking timing. It looks to be running very rich as the only way to get it back up and running was to unplug injectors to clear out the fuel. Once started

You read my mind for my next question of “what happens if max advance isn’t enough” 😂

That’s great thank you @siteunseen I’ll aim for the cold and warm values to start. Do I need to unplug my vacuum advance to get an accurate reading? another thought I had while rewatching the video. Any particular reason why it sounds so lopey? Not that I don’t like it, but I want to make sure all is okay! Possibly due to the vacuum leaks? I’ll check spark for each cylinder just to be safe as well. I can’t imagine my ignition timing being within spec either as is.