chaseincats

Who knows at this point - at least it's running though

Final update: We probably fried the TIU because it no longer sent spark timed properly and some cylinders never got spark after the fact (we tried flipping plugs, wires, etc but the box simply wasn't telling the coil to fire for cylinder 5 at least. We swapped the car to a 280zx matchbox distributor and it started right up. All that to say, do not bypass the ballast resistor.

So while driving, if the fan was directly connected to the engine instead of through a clutch for example, cooling performance wouldn't really change all that much?

Just gave it a shot and when its cold I can spin it about a quarter turn which seems pretty good. That said, when it's warm I'm able to spin it considerably more than that, shouldn't the opposite be true because it's supposed to grip harder to move more air when warm?

That's the strange part, the most air the fan ever blows is when the car is first starting

I heard that the american-made ones make more fan noise because they grip harder. The aisin one is brand new, so it should be good but its just not moving as much air as it should I feel. While the car is running it wont even blow a rag if you put it behind the fan

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.