Fuel rail vaporization

[Bruce Plecan]

> Howdy everyone , the weathers starting to warm up here Downunder  , I took
> the Ponty for a drive yesterday and now in traffic I am getting fuel
> vaporization problems at idle and part throttle. Outside ambient temp is
> about 35 deg , soon to rise to 40 deg as summer hits and the problem shows
> up when the intake air temp rises above 85 deg.

Could this just possibly be due to the change in fuels, is this common?.

> I have already blocked off exhaust crossover in manifold , added auto
trans
> cooler to fuel line,

Depending on exactly how you did that it might be serving to heat the fuel
more then cool it.  Gas flowing thru a line does alot to stay cool,
attaching a *good* cooler, might be acting as a heat exchanger in the
opposite way to what you think.

> moved the pressure regulator so that it is above the
> fuel rail. When it starts I can hear the fuel pump "groaning" and the
engine
> runs lean.

Hmm, any pressure/vac in the gas tank?.
Internal External Pump?.
Pinched intake line to pump, causing it to be prone to cavitating?.
Restricted return line,  Might be just enough to blled the presure down but
not freely circulate the fuel?.

 Would raising the fuel pressure help or would it be better to
> have a bleed off to keep the vapor bubble out ( I assumed the pressure
> regulator would perform this function). has anyone experienced this and
> overcome it ? any help would be appreciated.

On all my carbed stuff I'd run a good fuel air vapor seperator.
Used 2 Ts a cap a reducer and went something like this
Fuel in a mid height of the accumulator
Fuel out at bottom
at the top was a restriction of like .015" leading to the return line.

The fuel in was thru a t fitting so there was a *sediment trap* at the low
point just to make sure nothing could get stirred up enough to get to the
return line restriction.
The out was thru a second T fitting
The return line was thru a reducer on a 3" long piece of stand off pipe to
give the fuel enough volume to actually seperate.
The *housing* was using 3/8" steel pipe.
Then all lines were AN.
Remember the vapor is bomb making material, and you need to get real real
real picy about how you deal with fuel vapors.

I wonder at times how many fires are from Charcoal canister problems
Bruce

>
> Daniel Collins
> Hot Downunder
> Days like this makes yah want to fit aircon ! ,maybe I am getting spoilt
> driving a late model car during the week .
>
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