Zed Head

I seem to recall that some aftermarket timing chain sprockets don't have notches. It's the sprocket that has the notch. I'd focus on that damper first. It's a very important part even though it doesn't seem to do much but spin.

https://www.mecum.com/lots/FL0117-268010/1972-datsun-240z/ You can watch it live. They're at 81.1 https://www.mecum.com/auctions/kissimmee-2017/live/

You might have a later model damper, with the timing tab on the passenger side, or vice versa. You need to find out what's going on, because if your damper has spun then it's failing, and could cause more damage than just a misplaced timing mark when it lets go for good (bad).

Might be something in this link. Different year but the parts are probably similar. Probably a good Knowledge Base article. @Mike

It's already been deleted by its author. Wonder if the scammer watches the forum.

I was just trying to help you sell your car. A 1983 350 low compression smog motor is a whole different animal than a "built" 350. Just looking for some general words describing it. Did it come from a certain car, unmodified? Or is it a freshly rebuilt engine with performance parts? As Patcon says, there's a wide range of possibilities.

I've never heard of that o-ring air leak problem until now. Do you have even have the original pump in your car? Most have been replaced with aftermarket.

The sound was probably not air (but might have been) but just the gas squeezing past the internal valve in the FPR like it's supposed to. But usually it's just a steady "ssssss" noise. When my garage pump started to lose pressure you could hear the rotation of the motor starting to stall like it was binding up. So the noise is a clue. There's no o-ring to leak, at or in the pump, though. It's just a hose on a tubular fitting or barb, and a tight clearance metal roller assembly inside the pump. Here's one thing that comes to mind though - a hole in the tank's pickup tube. This would cause air sucking when the fuel level got low. I can't remember if you mentioned fuel level but you might watch and see if the problem only happens at low fuel levels. Fill up and see if it goes away.

There's a chart. The 160 must be like the Death Valley special recommendation. I assume that Standard came from the factory. 180 is pretty common across manufacturers, probably because they all burn the same fuel, I'd guess. But fuel has changed since the 70's so maybe the original recommendations don't hold anymore.

Edited - too many words. I'm not sure the guy that wrote the article really knows what he's talking about. But you can always go back. Are you "outing" Blue as 4-6-8?

This is counter-intuitive. Not seeing the logic. Is that from atlanticz.ca?

Maybe some oil in the coolant would help? A worthy experiment? No...? I count 7 and a half.

Ya know...there is a theory out there about backpressure from a restricted exit raising the boiling point of the coolant on the engine (pressurized) side of the pump. I think that's why the racers use about a 5/8" hole in a washer or metal plate when they run no thermostat. Could be one of those "racer's edge" things, but still worth a consideration. We should probably be measuring coolant pressure in the engine itself as a guide to most effective cooling. More pressure reduces hot spots and "nucleative boiling" (I made that term up, but it might be real).

Isn't a sequential mainly for drag-racing? You can't jump a gear with a sequential box.

The noise could be from a clogged inlet filter. They don't like to pull. Edit - by the way, that 392 pump is waaayyy over spec'ed for the L28. 670 horsepower? 50 gallons/hr at 80 psi? Not gonna get there, not necessary. http://walbrofuelpumps.com/walbro-gsl392-inline-fuel-255lph-pump.html

That's a great reference from atlanticz.ca. The drawings in the FSM don't give a good idea of what they actually look like. I cut out the part that shows the notch and groove, although the yellow arrow is off a bit..

Here's a picture from the FSM showing the notch and groove inspection. The groove is on the plate behind the sprccket and the notch is in the edge of the sprocket, next to the plate.

I think that he's kind of looking for a car that's done and street-ready. Basically, a trade, a race car for a street car. Sounds like he's in Europe and the car is in Fall River, MA, so a deal might be difficult.

You have a way of posting that is somewhat similar to another CZCC member from Panama. Good luck with the search.

Isn't the 240Z a running sports car? Or is it track only? Maybe we can figure out what exactly this is with a few more clues. Have you ever been to Panama?

People have had issues with fuel pumps that overheat. I had one (just a tester in the garage) and FastWoman had one, in her daily driver. Took her quite a while to figure it out. The pump can be turning, just not fast enough to generate pressure. So you'll hear it but pressure will still drop. Leaving a gauge on the system while you have the problem will offer a clue.

I just saw your pictures on the other forum. You really should take some time to think about the combustion cycle and the various things that need to happen in sequence. You're way back at 101 level, no offense. Get the damper mark, and the cam marks (notch and groove with the chain tight), and the points about to open (the bump on the distributor shaft), and the rotor pointing at the correct plug wire (#1). All together, at the same time. Just start by turning the engine in the proper direction until the damper mark is at zero, then look at all of the areas I listed, and make sure things are correct. The notch and groove are shown in the Engine Mechanical chapter.

Set the mark at 10 degrees and remove the distributor cap. Make sure that the #1 cylinder is the one that's getting the spark at that time. Where the rotor is pointing, and the points will have just started to open. With all of the things that you have going on you probably need to start from scratch. It's actually very easy to do, just get the various parts aligned.

I think that there's a picture in jalex's thread.