spec 7 guy

In Colorado where the altitude is in the neiborhood of 5000 ft, all 1st gens which road race vaporlock on warm days. I've been told that this problem does not exist near sea level. The only reliable fix for the problem is to use $4.00 per gallon race gas, which has less tendency to vaporize. I have tried insulating my fuel lines and running a cool can, with dry ice even, and it vaporlocks unless I have race gas. What really aggravates me, besides the $4/gallon and the hassle is that I've read that rotaries make more power on low octane fuel than high octane race gas because of their combustion chamber shape.

So if someone has another solution to the problem, or even an understanding of why the problem occurs on 1st gen RX-7s more than other makes and models, I'm all ears!

Thanks!

85RX7GS

iTrader: (1)

Well, maybe it's time to think about relocating? I myself wish to do so as well, but not to Colorado. Anyway, try Felix Miata's page - maybe there's something there.

peejay

Are you running a return line in your fuel system?

spec 7 guy

Yes I am running a return line

Viperx7

iTrader: (4)

I had the same problem with mine for the longest. I used to leave the gas not completely tightened and it worked most of the time. Just make sure if you're autoxing, that you don't keep alot in it. It will leak some when you go into corners. Not a real good thing, but didn't feel like dropping the tank. Anyway, finally dropped the tank and one breather line was clogged with a piece of metal. Blew it out and haven't had a problem since.

innertwist

iTrader: (3)

I know this is an old thread, but I read here that you can use an emission gas cap. It should work on 7's as well.