I am getting  fuel percolation at both carbs due to the amount of heat radiated by the manifold. I even replaced the fuel rail with rubber hoses this weekend and was still getting rough idle under a heavy traffic at 11:00 a.m. bumper to bumper. Car started to hesitate and stalled a couple of times. However i did found this company called THERMO-TEC which provides solutions to wrap the fuel lines and wrap the heat shield extensions:

http://thermotec.shptron.com/c/heat-protection?pp=8&pg=2

Which of all the products they sell can work to wrap the fuel rail and cover the heat shield extensions?

 Curious if there was ANY improvement after bypassing the steel fuel rail? I'm of the opinion that wrapping fuel lines retains heat that comes from the fuel rail mounts, but that's just a theory and probably only part of the problem.

no improvement! the same fuel percolation! We bypassed the fuel rail with 5 inch rubber hose and fittings and when we got stuck on a big traffic idle became lumpy and car tended to stall.

 Hmmm. I was hoping that it would have had some effect. Specifically, It would have taken longer for the issue to arise, or perhaps wouldn't have been as severe. Looking at your engine build and ambient temperature in Panama, an under hood fan may be the answer. I'd also consider a vented 280Z hood or louver the access panels on either side of the hood. Just for kicks, the next time you're in the conditions that cause the heat soak (traffic), try pulling the hood latch to allow the heat to escape, just to see if that will prevent the problem.

have you ever tried adding some choke when it starts misbehaving?

Well if you add choke it clears up. I read that some people in Australia where there is also high temperatures are installing a 280zx injector cooling fan as per the pictures attached. Could this posible help besides from adding a layer of thermo-tec insulation adhesive foil to both of my heat shield extensions?

6 minutes ago, jalexquijano said:

Well if you add choke it clears up.

Why did you remove the mechanical fuel pump to begin with?

car came with no mechanical pump! pictures above are not from my car. My car came only with an AIRTEX 8012s electric pump.

http://www.zcar.com/forum/10-70-83-tech-discussion-forum/406009-fuel-percolation-3-screws-su-carbs-bowls.html

 

Quote:

Originally Posted by princejqman 

In addition to the stock heat shield which was installed in the car by the Factory originally, i have mounted a Stainless Steel heat shield extension that reaches the bottom of both 3 screws SU Carburetor float bowls. However, the fuel percolation is still present. The gasoline in my country, Panama, has no ethanol so this should not be happening. The heat comes directly from the manifold and thus there must be away of lowering that amount of heat so it does not affect the fuel that is inside the float valves and that will evaporize and consequently shut the engine down. Other owners only throw out ideas such as swapping metal fuel rail with 5 inch rubber hoses or driving with the lid off? Is this really going to help and avoid the car idle becoming lumpy at traffic jams which leads to a sudden shut down of the engine? Wouldnt it be better to find a way to lower the temperature at the stock manifold? How about ceramic coating the stock manifold?

It's been fun but I'm done.  You have graduated to my Ignore List.

Do i really need to source a mechanical pump and use it all together with the AIRTEX 8012s electric fuel pump?

 I don't think you're going to solve this with one fix. This is the type of problem that you'll have to chip away at. I think the blower is a good idea but it may take more than just that. Two pumps are recommended for a heat soak problem. Is your new exhaust close to the fuel lines in the tunnel?

Mark,

I think you can really help me at this. Asides from installing the recently purchased 280zx injector cooling, should i purchase the mechanical pump and install it back again? My new exhaust is an MSA PREMIUM EXHAUST FOR STOCK MANIFOLD:

http://www.thezstore.com/page/TZS/PROD/15-6302

I am also considering pasting a layer of thermotec to both of the stainless Steel heat shield extensions:

https://www.amazon.com/Thermo-Tec-13575-Adhesive-Backed-Barrier/dp/B00029KC2K/ref=sr_1_2?ie=UTF8&qid=1495143830&sr=8-2&keywords=thermotec

Will it really help getting that manifold heat out of the way this avoiding fuel percolation at the fuel bowls?