chaseincats

No ideas on a grippier fan clutch?

Where is the reverse-engineered info located? I'd love to read that.

That's absolutely true and that's why the TPS drops the ratio to around 12.5 when you floor it but 14.7 is the ideal ratio for highway driving

Update: After getting the car back from the radiator shop they are recommending a stronger fan clutch since the Aisin one I have doesn't move ALL THAT MUCH air (it is brand new and replaced one that moved just as much air). Are there fan clutches out there for our cars that grip harder and move more air? It might be running hotter since I run the car at a stoichiometric air/fuel ratio instead of the richer configuration they come with. The car was set that way by me using an air/fuel gauge.

really interesting watch, thx

It comes out of the area where the wire gets plugged in regardless of if the booth is pressed on or not

The weird thing is we tried that, tried every plug wire we could and still got spark coming out of the coil

A quick update for you guys: We went and grabbed a coil/resistor from a friend yesterday and hooked everything up and noticed the car now (and apparently was slightly before) arching the spark from the coil to the body of the car and the spark plugs were getting pretty weak spark overall (and are BLACK). The EFI is definitely working as the entire engine smells like gas and I went through every single test in the EFI bible and all the systems check out. We then opened the ECU to see if anything was burned out from the extra power when we didnt use the ballast resistor and it looked fine. The plan now is to take the ballast/coil back to my pal and grab an e12-80 distributor and bypass the possibly fried TIU and use the 1.6 ohm coil the car had on it before that worked with the crane x700 ballast-less ignition module. I will update you guys in the next few days but I'm happy as a clam that its a spark and not efi issue.

I’m with the car now and am noticing when they key is in “on” but the car not running maybe every 30 seconds all injectors will click at once. This is baffling, any ideas?

So since he has a 1.6 ohm coil, he is missing 0.8 ohms off needed resistance or is that safe enough not to damage the TIU/ECU? Any idea about the high pitched noise from the coil and quick spin of the starter? It sounds like there's some interfernce somewhere or something?

Interesting, I wonder why Datsun didn't do that from the start... I talked to my friend with the car and he said the coil is making a high pitched noise after removing the 700 box and noticed the starter turns for a split second when the key is put in 'on' (even before the key is turned to 'start'). Both that odd side effect with the starter and the coil's high-pitched noise started after the 700 box was removed. I'm assuming these are related somehow, any idea what could be causing this weird behavior?

The odd thing is there is spark and there is fuel injection pulse. The car ran with the current timing until we changed the throttlebody so its probably that.

Gotcha, we will go find a ballast resistor then and hopefully we didn't fry either the ECU or TIU The interesting thing is the car worked perfectly with the throttlebody it had on it, but once we switched to one that didn't look like it came out of the bottom of the titanic the car refused to start, maybe we knocked something during installation

Gotcha. It seems the coil in there was ~1.5 ohms. Could that cause any damage to the TIU or ECU?

My friend has a '75 280 that had a crane x700 spark box on it which we removed. After reconnecting the stock ignition system we noticed the ballast resistor had been removed by the PO. Using the 12v coil the crane module used, would connecting both power wires to the positive terminal cause any long-term damage to the stock transistor ignition module? The car runs when wired that way. If running it that way will cause an eventual issue on a '75, what did Datsun do to the '78 model since that was the only year that didn't use the ballast resistor?

Ran the car without a thermostat and it got up to the temp it gets with the thermostat in it (albeit took a lot longer to get there of course). I also had the block/radiator power flushed and not much rust came out which either means its REALLY clumped up in there or I got it all out flushing it a few times.

Does anyone know where/if you can buy the reluctor wheel for a 280z distributor? We tried to take the one out of a broken distributor to fit a working on and ruined the teeth.

Definitely a fair point but I grabbed an IR temp gun and verified that the engine temp was fluctuating and not a goofy gauge 😞

Alright, I'll give that a shot. Again, it's not about being precise or 'that's a fine temperature.' The car is running differently than it was before which is indicating there is an issue. The fact that it is not bad yet doesn't mean the issue should be ignored. The difference isn't only the temperature it's getting to - the main difference is the temperature flux between idling at a stop light and driving with air through the radiator. Before this issue started in 2020, the needle got to 170 and never moved regardless of idling at a stoplight or not.

It’s not a boiling issue (at least not yet), the issue is that it isn’t behaving like it was last year when this issue started which tells me something is wrong and will eventually get worse.

It might go a bit below 170. Even though 185 to 190 isn’t a huge issue (arguably an issue at all), the fact that it used to get to 170 and sit there regardless of if I’m idling or driving freeway speed means something is not working as it was/should, you know?

As long as I've owned the car it was never full because the old radiator had a pinhole leak at the top and didn't hold pressure but always kept the car at 170. The new radiator is filled to the brim but not the reservoir tank. If the car's problem was the head gasket though, wouldn't it run warm all the time regardless of airflow through the radiator?

Gotcha. I will be out of town so I can try this in a few weeks. The reason I was trying to go around this is paper gaskets do not seal my thermostat housing - each time I pop it open I need to seal it with RTV. Regarding head gaskets, one thing I don't understand is if I accelerate hard and shift, there will be a puff of white/sweet smelling smoke out of the tailpipe (coolant) but when I pressurized the cylinders for the leak-down test, there weren't any bubbles in the radiator. Also the exhaust gas in the radiator tester with the blue liquid did not change colors either. I don't understand how coolant makes its way into the cylinders sometimes but does not show up in any tests.

Just so I understand, what would it running better without a thermostat or running worse tell us?

With the old smaller thermostat the car would get up to 180+ at idling but when starting from a stop (at a traffic light for example), the car would drop back down to 170 after a few minutes of air flowing through the radiator at road speeds. With the new larger opening thermostat, it will get up to 180+ at idle but when starting from a stop with this new thermostat, the car drops to 170 within a matter of seconds - the car is cooled way faster with the larger OEM thermostat. I have not driven the car without a thermostat because the car never had this problem with the old OEM thermostat (until 2020). The new OEM thermostat that's in the car now was tested in a pot of water so I could confirm it was working as it should and at the proper temperatures before installing in the car. Driving the car without a thermostat might keep it slightly cooler but that would be a bandaide and not fix the real problem.