Mark Maras

My clear filter was never full when the engine was running. Never had a problem with lack of fuel to the carbs and the fuel level didn't change with a new mech. fuel pump. Never have figured out the "Why".

The engine revving freely, but not when it's under a load is lack of fuel. Not much to tear down. Pull the chambers and pistons, clean everything and be sure the pistons drop freely. Pull the float chamber tops, The needle and seat (fuel valve) is under the top. The trickiest part is setting the floats.

@jalexquijano

Does the engine rev freely when it's not under a load? Patcon is right. That doesn't look like much fuel for a four minute run. A fuel pressure and volume test will rule out lack of fuel up to the carbs. Any crud in the float bowl is bad. The crud can slosh it's way into the needle and seat, potentially, either partially plugging the fuel orifice Lack of fuel) or stop the needle valve from seating. (too much fuel) depending on the size of the crud. Be sure to remove and clean it. I'm curious if the floats have deteriorated to the point that they don't float at the proper height anymore. On the outside of the float lid, where the fuel line connects, clean the small (last chance) filter (fine screen) located in the banjo fitting. Check the float height, reset the mixture screws to 2 1/2 turns and fire it up.

Should you desire to practice on one first, I have a 71 dash that leaves much to be desired. I doubt you could make it look worse. No shipping. You're about 3 hours away.

The 2.4's and 2.6's? used the spray bar. I don't know the exact changeover date.

Wheee! nailed it. Burton Cummings. Heck of a vocal range and a great piano player too. American Woman is a classic and the message is still pertinent. No Sugar Tonight/New Mother Nature is still my favorite.

Likewise. My family is well versed in giving me "THE LOOK" when I do something stupid again.

Keeping it waxed is gonna be the real challenge.

I agree, love the science. More pieces to add to the grand puzzle. I think most of us members are autodidacts with a touch of O.C.D. and masochism thrown in.

Sorry, I don't have a recommendation. I haven't used any insulation in the past. I don't remember if you wrapped your headers. A stock intake might be a good thing to try. Should be easy to source from a member. Not sure you'd need it but have you checked to see what ceramic coating costs are in Central America?

Mine too. The power drill hooked up to the pepper grinder was one of his finer inspirations.

I doubt anyone here has tried wrapping the intake. I doubt it would help the problem. IMO the problem is heat in the fuel lines and maybe the float bowls.

I agree with Patcon. I doubt that this is going to be a one step fix. You'll have to keep chipping away at it and eventually you'll get it to the point where the worst symptom is the engine taking a few extra revolutions to start in the heat. If cracking the hood helps (probably won't cure all of it) the situation, you might want to consider a vented 280 hood or louvering the access panels next to the hood to vent excess heat.

@Patcon There's unlimited recipes for sauces, rubs and different wood but the best advice I can share for barbecue (not grilling) is Low and Slow. Temp somewhere between 200` - 225` F and hours of cooking time. 3-4 hours for ribs, at least 6-8 hours for a brisket, minimum. To late for rib pics, tho.

Lightnin Hopkins

@Redwing I don't know much about the whooshing sound from the tank. When you loosen the cap, is the whooshing excess pressure (positive pressure) in the tank or does it seem like a vacuum (negative pressure)? Anyone, Was the 76 gas cap supposed to be vented? Is the whooshing sound normal? The hard start symptoms are typical of a minor? heat soak problem. Interesting that Redbird only has a small problem with it considering the 76 doesn't have hood vents. You could try cracking the hood when shutting the engine off to see if venting the heat will help it start faster. If you definitely want to try the flex fan let me know and I'll ship it to you. Relatively easy to install. Just four bolts. Congrats on getting the AC working. Z's can be brutal in hot weather.

Very very nice. We all wish we had one that good to start on.

I think I saw a little beetle in the garden that looked like that. Draw some legs on it.

I do think that's how it's supposed to work, in theory, but what if, when the engine isn't under a load and not using much fuel, the valve doesn't allow enough fuel to return. Now I wonder what, if any, change has anyone had when they removed the valve but kept the return line? Can anyone enlighten me on the purpose of the valve in the return line? Is it just a Miss Tilly's Orfice in the return line? I too am working on a slab of St Louis cut pork ribs. BTW, you left an o out of cooking, Freudian slip? Stay safe, in all ways.

I too, have pondered the why some do and some don't. The earlier the Z the less chance of heat soak, it would seem. Could it be that one of the larger puzzle pieces that is almost ignored is the fan. The heat soak problem happens in traffic (low to no speed), idling, and after shut-down, all in hot weather. It never happens at speed. At least if the engine is near stock. (the cooling system doesn't even need a fan at anything over about ten mph) So my line of thought is fan clutches. The resistance in them is all over the place, with varying ways of testing them. Personally, I've thought they sucked (definitely no pun intended) from the first time I owned one. I was never convinced that they were very efficient at pulling air, depending, of course, on how much resistance they had. A fan shroud would definitely help the alleviate the problem too, IMO. When the fan clutch froze up on my early 71 (metal fan), it sounded like a Cessna throttling up and it felt like the engine was down on power about 25%. Since I had a lousy opinion about the fan clutch to say nothing of the weight of that steel fan, I bought a flex fan with an extension. Previously I hadn't experienced drastic over heating. The temp would go up a bit in traffic. No heat soak problem. The flex fan did pull more air at idle. The temp didn't go up quite as high in traffic as before and it seemed like the engine revved faster. Probably because I dumped the boat anchor steel fan. The fan has to be a key element since it's job is not only to cool the internals of the engine but the externals too. BTW, If anyone with heat soak and is desperate enough, I have that flex fan set-up which could be borrowed to see what difference it makes, if any.

My G3 filter was never full and I never had a problem with the float levels or lack of fuel. I gave up wondering why, years ago. One can pull the chambers and pistons off of the carbs and check to see that the fuel is 1/16" below the top of the fuel nozzles. Easier than pulling the float chamber tops.

I believe you're correct up to a point. I don't, however, believe that the reason for the added pump was flat top carbs. The engines used the same amount of fuel regardless of which carbs they used and the mech. pump alone supplied enough fuel to run the engine at any speed. The elec. pump by the tank added pressure in the lines prior to the mech. pump, possibly raising the boiling point of the fuel or just compressing the fuel to try to prevent the fuel from vaporizing in the lines. At least, that's my theory.

The original Z's only had a mechanical pump. Nissan added the elec. pump (among other things) to try to cure the heat soak problem. I can't say for sure if it will help but it can't hurt.

No complaints from Oregon, we are the Beaver state.