Vapor lock year two, the good fight is back on.

[5thhorsemann]

It's 100+ deg again today, the car is running really bad at higher RPM. I didn't want to thread jack the octain thread, so here we go.

I just ordered a Holley blue pump with a regulator to replace the pogo pump. This is about the last thing I haven't tried among the common remidies like insulation and heat shields. I thought about cutting the hood, but I have never seen a hood scoop that looks as good as the solid 240 unvented hood. My hood has a dent, but my body man says his father's a TV repairman and he has the ultimate set of tools and he can fix it. (thats for the old guys out there) So I figure that if I must cut the hood, now is the time as paint is coming soon. Any of you guys done a hood scoop (other than the Nissan part, not too keen on them) that looks like something? If so pics please. I was thinking that a Mustang cobra scoop might be a candidate, but it looks like alot of fitting work. That would look sort of like the old big block Vette hood, sort of. (no Klingon pics please)

So, back to the holly pump, I'm a little afraid that the pump might blow by the SU floats and spill raw fuel in the engine compartment. Has anyone put a catch can on your SU bowl vents? If so what did you buy or make and where did you install it?

[grantf]

but my body man says his father's a TV repairman and he has the ultimate set of tools and he can fix it. (thats for the old guys out there)

Who are you calling old Spicoli?

[5thhorsemann]

Who are you calling old Spicoli?

US, you know who you are.

[Walter Moore]

The Holley pump that I used has a red label on it (For what that is worth.) I mounted it back by the fuel tank, and have never had a problem with fuel spillage from the carbs. I assume that the return line must be working...

I have electric fans that run off of a thermostat I installed in the carb heater line. I generally don't have any issues with vapor lock. I haven't driven the car much in 100+ degree F temperatures, but just because I don't like sitting in a pool of my own sweat.

[240260280z]

If you have enough pressure and flow from the pump then enlarge the orifice in the tip of the return line on the fuel rail to get more "cooling effect" (heat extraction) from the fuel that only passes through the rail and back to the tank.

[SteveJ]

Funny, I just fixed the vapor locking problems on my 260Z. It was missing the insulation on the fuel line going to the front carburetor. I bought some Vulcan Fire Sleeve and slipped it over the fuel line. I drove it around in 90++ degree weather with no signs of vapor lock, despite the issues it had when the weather was 20 degrees cooler. What type insulation did you use on the fuel line?

[Scarab155]

I would punch some louvers in the hood (and inspection lids as well). I have this on my Scarab Z and they really do a greatv job of venting the heat from the engine bay. They also do not spoil the lines of the 240Z hood. Just my opinion.

[5thhorsemann]

Walter, I have considered the fan idea, but haven't yet found a fan setup that looked like it would be both ellegant and trustworthy.

Blue, great idea, as usual, I will be sure to add that modification when the pump goes in.

Steve, I used a ceramic wool, wrapped in FG mesh (header wrap) held in place using aluminum tape with the reflective side out. The fuel rail is isolated from the head and mounting hardware using pheonalic washers. I can't see how I could better protect the rail from heat.

Scarab, I haven't looked into the louvers, but it is a good looking alternative.

Thanks men!

[MotoManMike]

Sounds like a mixture issue to me, popping at high rpm tends to be a lean condition. What oil do you have in the dash pots?

[Zedyone_kenobi]

IF I get a vote, I think the scarab idea is brilliant. If you have to modify a 240Z hood, why not go something the old school datsun guys did.

Popping at high RPM is an issue that is near and dear to my heart. Lets just say that it could be a GREAT many things.

Fix the easy ones first. Then after you go freaking nuts, buy webers. HAHAHA

[gogriz91]

If you can get ahold of an original fuel rail for originalities sake I had my fuel rail "modified" and moved so it flows from the transmission tunnel along the firewall then to the carbs and had it wrapped with fire sleeve.

[5thhorsemann]

I got my pump today, it will go on this evening. I know the carbs are set up right because when the temp hits 97 to 100 degrees is when the problem starts. If I pop the hood at speed it goes away. I'll see what the pump does, It's not supposed to get hot enough this week to be an issue, so time will tell.