Gary in NJ

Good. Go into this as a skeptic and it will payoff. To protect yourself you have to assume the worst of people. If something doesn't feel/sound right, it probably isn't. If you hear something that doesn't ring true, ask some leading questions to see what else is revealed. You may have found a great car, but don't go on the sellers word or by an untrained eye. Have the car inspected by someone (a body guy would be best) you trust. I hope this car turns out to be as good as you hope. They are rare on the east coast. Post pictures. We love photos. BTW, that uncracked dash could be a cover. Take a second look.

My alarm just went off. Paint hides all sins.

8:21PM - Request for help 9:09PM - Insulting Members for not running to your aid Really?

From Wikipedia: "The Classic Car Club of America, maintains that a car must be between 20 and 45 years old to be a classic, while cars over 45 years fall into the Antique Class."

No Short answer, yes. I'd take the time to remove and plug the entire system.

Bruce, doesn't a '73 have the winter/summer flap on the airbox. Assuming that it's connected and properly functioning, that reduce the possibility of carb ice. Steve, have you tried the flap? I know from flying that carb ice can occur in temperatures as high as 80 degrees if there is high humidity. As a SOP, we add carb heat every time we are at 1/4 throttle or less.

That's exactly what I was thinking. A cleaning of the nozzles and perhaps new needles are in order.

The FSM states 5BTDC. For a stock motor I don't think you'd see much benefit from advancing that figure. I also don't think you would break anything if you had it advanced to 10BTDC. How far did you have the timing advanced that you blew a head gasket? That had to be some serious detonation to blow the head gasket. Adjust your timing for drivability, not horsepower. There isn't any magic horsepower hiding in the distributor.

There have been many good suggestions for straightening the flange but I wouldn't attempt any of them without heat applied to the surface. My suggestion is send 'em back for a unit with a straight flange. You paid your money, get what you paid for.

Outstanding. After all is said and done I'm sure you saved over $750 from what the "pros" charge. You'll have a lot more pride in your result then from writing a check.

Problem on both issues. Sounds like an intermittent short in the harness. Track it down before it causes real damage.

That's not how an engine is properly timed. You really need to get a timing light and set it correctly. The good news is that you discovered the root of the problem, now you need to resolve the problem.

The reason I asked the questions about loaded/unloaded conditions is that carburetors will behave differently under load then when lightly loaded. The fact that this doesn't effect the 5,000 rpm ceiling leads me to think that this is an ignition or engine timing issue. Do you own a timing light? It's time to take some measurements.

I have a couple questions on the 5,000rpm ceiling: 1) Is this ceiling in neutral and all gears? 2) Does it only happen under heavy load (acceleration or climbing a hill)? 3) What happens if you slowly apply throttle to WOT while in neutral? 4) What is the condition of the fuel filter? 5) What is the condition of the ignition system (points, condenser, cap, rotor, wires & plugs)?

LMAO. That's the quote of the day right there.

Good call Chris. By the time I started typing I forgot where the poster was from.

I don't think Casey is trying to be funny. The 240Z requires a deft touch on the throttle. It is unique and has been a source of complaints from many an owner. Back to the problem...These are 40 year old cars and it is entirely possible that a prior owner screwed something up. Give something a try... Disconnect the return spring on the the throttle lever and see if that has a significant effect on the break-out force. It's possible that you have an incorrect return spring. If that doesn't help, it would be worth the effort to disassemble the ENTIRE throttle linkage & interlock link on the carbs to determine if something is corroded or otherwise binding. Check the spring first 'cause its easy.

From the description it sounds like your car car has a vapor lock problem, i.e. the fuel in the fuel lines boils off from excessive heat and air gets trapped in the fuel line. This vapor lock is self clearing when the fuel line temperature returns to the normal range. The fuel return rail is supposed to keep this from happening, but in some cars it does happen. As a "quick fix" you can try insulating your fuel rail and return lines. If I were you I would also check that the return line isn't clogged or disconnected/modified. While this seems like the most likely resolution, don't rule-out a problem with the ignition system.

I don't know Mark, everything seems to be working real well. Are you new to 240Z's? I've never owned or have driven a 240Z that didn't have a high break-out force on the throttle. When they get gummed-up out or of tolerance the car is almost undrivable. When they are sorted out they are stiff but you can develop a feel for the correct touch in a day or two of driving. From what I see in your videos, your carbs are functioning well.

Didn't I just read a few days ago that there is a profile that is better suited for E10 fuel? Worth asking Bruce about.

Wow, the oil filter debate is only second to the oil debate. Every automotive/motorcycle/airplane/tractor forum I've ever belonged to in the past 20 years gets dragged through this one. When do we start discussing politics and religion

Back in my younger days I had louvers on my '71 240Z. But then again, back then I thought Walmart was a good place to buy auto accessories. If you car lives outside, louvers will: - keep the carpets from fading - make it harder for people to peek in - keep the interior cooler

You did well with the car. The rims alone are worth $800. How long has the car been inactive? You might want to read the many threads on how to start an engine and service a car that has been sitting. The limp clutch is from air in the hydraulic clutch system or a worn master or slave cylinder. Bleeding the system will go a long way in diagnosing this problem. Congratulations on a good find and welcome to Z club.

Mark, I had the same problem you describe in post 17. I cleaned (removed and polished the inside of the plastic and the ball with a Scotchbrite pad), lubed (white lithium grease) & adjusted the throttle rods. The rod from the bell-crank to torsion rod was on spec (7-3/16") but the rod from the pedal to the bell-crank was long. It was readjusted to spec at 4-1/4". This mostly cured the problem. Believe it or not, the final thing that made the on-throttle transition much smoother was a clutch adjustment. My clutch was engaging too high and when I lowered the engagement point the high break-out force of the throttle wasn't as noticeable.

Any good oil filter (Filter Fram PH8A, Purolator L30001, NAPA 1521) will work fine. For viscosity check the FSM (I'm not sure how cold it gets in TX). I drive my car 9-months and use 10W-40. I tend to use the "high mileage" formulas. FYI, Walmart will take back used oil.