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?

I have a very similar set up on my 240Z, only I have the Holley red pump. 4 year old pump died, so I bought a replacement. That one was dead out of the box. Took me a while to figure that one as I never expected that to be the issue. Next one now has "locked up" twice on me. By that I mean that the pump sounded like it was on, the humming noise (loud) that it usually makes, but no pressure. Took everything apart and thought vapor lock since the issue, no pressure, finally went away. The second time no pressure again, but pump was a little quieter. Checked a few things before deciding to knock on the pump. Once I did that, the pump jumped in volume and pressure was flowing.

Just not sure about Holley quality any more is what I am trying to say. Hopefully you have better luck. I am going to try a pump from Airtex, I think that is their name, who makes most OEM pumps for the major manufactures. It is said to be much quieter and more reliable. Time will tell. Good luck with your set up and I hope it takes care of your vapor lock issues!

Amazingly, 721 never had a vapor lock issue with either the SUs or Mikunis. I had removed the mechanical pump and installed a Stewart Warner "thumper" pump years ago (40). I had the fuel lines routed adjacent to the original lines, up the firewall, over to the center of the car, then forward to a fuel block mounted with the intake/exhaust studs then to the carbs. Pressure was regulated at the pump at just below 6psi. No return line was used.

Vapor lock is a varying mystery, isn't it?

I've used the Holley pumps in the past, never had a problem with them. Since I'm using the returne circuit, the pump should run stress free, as long as there is pressure at the suction side of the mechanical pump, it should be fine.

I will be watching everything closely for a while to make sure I don't overfeed the bowls and wash the motor down. Like you said, time will tell.

Update, looks like this did the trick, it's been in the high 90's for the past two days and no sign of the problem. I do still have to get used to the buzz of the new pump, it's loud compared to the old thumper.

Try running a rubber insulator between the pump and bracket.

Try running a rubber insulator between the pump and bracket.

The pump bracket has a rubber isolator built in, I dont see how to further isolate the noise and still have a secure mount, I just have to learn to live with it.

Is that a FG hood or just a 3" scoop mounted to the stock hood? I like it, and just ordered a FG cowl scoop for mine. http://www.ebay.com/itm/150852819409?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649