Captain Obvious

Nice! Sounds like you've seen some good classic DLR! Now just hope he doesn't sprain anything on stage!

As Zed Head already mentioned, the (normal) injectors won't fire because the ECU won't see any ignition cycles. However (seems there's always a however, doesn't it?)... If the engine is cold enough, the cold start injector will fire using the wire off the starter technique. Depends on how cold the thermotime switch is. The AFM manual movement doesn't have that drawback. So if you're used to just moving the AFM vane a little bit with the cover off, then using that method is just fine. One more thing though... All that said, if you have a fuel pressure gauge installed already, you should already know if you've got pressure in the rail even after sitting overnight. Just look at the gauge.

First thing I would check is to see if your fuel pump check valve leaks a little and is allowing the fuel pressure to drop off overnight. If you don't want to go through the hassle of installing a fuel pressure gauge, you can get an idea if that's what's going on simply by pressurizing the fuel system before you try to start the car. On those mornings when the problem "would normally occur", pull the starter solenoid wire off and turn the key to START to get the fuel pump to run without engaging the starter. Then after a couple seconds of that, put the wire back on and then try to start the engine normally. If it starts instantly, then that's probably what's happening. If it still takes just as long to start even after making sure there is fuel pressure, then maybe there's an issue somewhere else. I've removed my cold start injector, so mine takes a couple cranks to start because of that. I'm OK with the delay as a trade off for fewer leak locations and simplicity.

I don't know what the input resistance is looking into the CTS circuit on the ECU. If yours is working correctly, I'm gonna say it's about 1.8K Ohms.

Good. If anyone has a dead rack they would like to donate to science, let me know, and I'll put it on the cadaver table for some exploratory surgery!

Haha! Fuel on the mind?

Haha!! So no Sammy love, huh? I can listen to all of it, but I agree... The best stuff is the early DLR stuff.

Funky! Maybe it would be prudent to make sure the two bronze bushings on the ends of the housing are still in-line? Should be pretty easy to check... Slide the rack in and make sure it goes all the way through without any binding? I'd love to cross section one of those. But the only one I have is on my car.

The readings (that I understand) look perfect. It's a 1K Ohm potentiometer, so you should see zero at one extreme and about 1K Ohms at the other. Those look great. Your CTS cold sensor indicates about 60F, and your CTS hot sensor indicates about 180F, so (assuming it was about 60F in Ventura County at that time) those look great too. The only thing I'm not sure about is the 1.82K Ohms your getting on that other reading... What do you mean with "CTS ECU harness"?

Van Hagar.

Well that's probably not good. I had suggested they were epoxy, but I should have been a little more specific. They are plastic, but I don't know if they are thermoplastic, or thermoset. Sounds like they are thermoplastic... So how much goop came out? Just tiny dots like what would fill the holes, or once it turned runny, did a large amount come running out of the holes? Like it was melting out of an internal cavity of some kind? Pics or it didn't happen.

We talked a little bit about those white plastic nubbins a little bit early on in this thread. My theory is that they have something to do with the fitting and alignment of the two major components of the rack tube. The rack housing body is made up of two parts... 1) A cast iron piece that houses the pinion gear and one end bushing, and 2) a steel tube that reaches over to the other end of the housing. I believe those white plastic nubs are some sort of epoxy used to align and lock the two pieces of the assy together. I'm thinking that since the alignment of the long steel tube into the cast portion that houses the pinion gear is important, maybe they loosely fit the two parts together, locked them in an alignment jig, and then used a hard setting thermoplastic to lock the two together. Inject it into the hole until it comes out the other side, and then let it cure in place locking the two parts in alignment. They did similar practice on the 72-on suction piston housings on the carbs, and they also employed that technique on the EFI throttle linkages. They aren't grease fitting holes. Not only are they too small, but if you look inside the rack tube, there are no holes through. No way for grease to get inside the housing to do anything.

I took the bolts out and left the holes open. I think that's how they were supposed to be stock. They are shrouded inside the rubber boots so as long as the boots are in good shape, they will stay clean.

Thanks Site! Here's my chart:

Thanks bud. I don't really know yet. I was close to home when I noticed the problem and managed to coast 90% of the way to my garage with the engine shut off. I let it cool off in the driveway with the hood up, and then after it was cool, I started it and put it away. It started and ran fine, so I'm hopeful I didn't cause any permanent damage. I'll do a compression test in the spring. I appreciate the help, and I'll keep you posted! I've got an F54/P79 motor here that I've been meaning to drop in...

Thanks guys! I did consider an idiot sound as well, but I didn't think I would hear it. Windows down, exhaust singing, valves-a-clickin, and the radio playing 80's hair metal at volume 11. No way I was gonna hear a beeper. I figured that the flashing warning lamp would catch my eye even in my peripheral vision. I won't know until the spring how it looks on the road though. I'm also considered wiring it into the oil pressure as well. It would be a pretty addition at this point. I'm torn between sharing the same warning lamp for both functions though. It would certainly be easy to discern which of the two faults caused the lamp to come on, but it would sure be more glamorous to have one for each gauge.

On my last drive of this past driving season, my engine overheated. It wasn't intended to be the last drive, but unfortunately that's how things worked out. The failure was a split in one of my engine compartment coolant lines and I lost most of the coolant. I didn't know anything was wrong until it was too late. I never noticed the temp gauge creeping up and I didn't know there was any problem until I saw wisps of steam while sitting at a traffic light. And by that point, it was too late... The coolant was gone, the engine was overheated, and the temperature gauge was pegged hot. It became clear that even though I believed I scanned my gauges frequently, it wasn't good enough. I needed a solution that got my attention. With that in mind, I decided to modify the gauge to add a warning lamp in addition to the gauge needle. The "Idiot light modification." Here's the faceplate for the temp/oil gauge. There is plenty of room on the right hand side to put an indicator light. First thing is to make sure it doesn't interfere with the needle. I put a piece of tape on it and marked the needle position at full scale and then marked where I could put an LED to use as an indicator such that it wouldn't interfere with the needle. The black dot above the "0" is where the LED will go: Drill the hole in the faceplate and insert an LED from the back side: Here's the front side with the LED in place: And here's the gauge reassembled with the warning light off: Warning light on: I haven't built the final version of the driver circuit yet, but just to test the idea, here's a video of proof of concept: https://youtu.be/itjYR885iik I will take some final pics after the drive circuit is worked out and the gauge is in the car. Here's to hoping this will get my attention if I ever have problems again!!

Nice car. Wish I had the money. And beautiful collection. I got a question though... Your ad says a "'71 240Z, 1 Owner" But then you say you purchased it from the original owner. How can that be a 1 Owner car if you're already the second owner? And the next purchaser would be the third owner, right?

Yeah, Happy birthday Chuck! I think for a birthday present, you should let me take you out for a ride in the Pantara. You would have a great time, and I would be happy to suffer through it for your enjoyment.

Well I didn't trust my memory, and good thing... I took a refresher look at the docs and all that crap I said about the ignition module was incorrect. The earliest modules had the pigtail design like the one you have there. The 78 version I was thinking about doesn't have a pigtail. It has the connector built right into the module. Sorry for the noise... I should have checked first.

Good luck with the sales. I'm not looking right now, but I can help refine the merchandise a little... The voltage regulator is not stock, and is an aftermarket (solid state) unit.

Dave, Did you ever measure the resistance the sensor drops to while hot?

Are you sure yours isn't working? Just because it's rusty, doesn't mean it has failed electrically.

There is no "threshold". The current is always being pulled through the bulb filament. It's just that when the sensor RTD is cool enough, the current is so low that it won't make the bulb filament glow. The current will gradually go up as the temperature of the tank sensor increases, and at some point, you'll notice it on the bulb because the filament is glowing bright enough to see it. In other words, it will glow dimly before it glows brightly. And it happens slowly. It's an analog function, not step change.

That sensor isn't a capacitor, It's an RTD. They push the current from the fuel warning lamp through it and it heats up. If it heats up enough, the resistance drops and the current gets high enough that it makes the filament on the warning lamp glow. The trick is... When it's immersed in fuel, it won't heat up enough for that to happen. But when the fuel level is low enough and that sensor is hanging in vapor (and not immersed in liquid fuel), it heats up enough to pass higher current. High enough to light the lamp on the dash. @Dave WM did some analysis and came up with the above.