[T3] vapor lock and spacers cont'd

[David Yaghoubian]

Wow, this goes back to 2005! (below). I am guessing my engine rebuilder, who
will remain nameless, didn't reinstall the phenolic spacers, and this is why
I have been chasing my tail ever since.

Should I go ahead and order two of these? I measured the gap between the air
cleaner and the top decklid and there is 1/2in, so accommodating these 3/8
spacers will work. 

https://vwparts.aircooled.net/Weber-34-ICT-and-Solex-34-PICT-Phenolic-Thick-
p/34mm-carb-phenolic-9mm.htm


-----Original Message-----
From: David Y <goob at adelphia.net> 
Sent: Thursday, November 17, 2005 10:57 PM
To: type3 at vwtype3.org
Subject: [T3] End of 1776 overheat saga and vapor lock Q. (long!)

Hi All,

.....

Now for the vapor lock question (I've got dual dual Solex H32/34 PDS13 with 
stock brazilian air cleaner setup, recently rebuilt and rebushed, balanced 
and running perfectly):  twice now when I've had the engine at full 
operating temp, parked it for 15-20 min, then returned to drive it, I have 
only been able to drive about a block before the engine dies (clearly a 
fuel starvation sputter as it chokes). The first time this happened last 
week, I could see that no fuel was present in the in-line filter, and in 
pulling off the line to one of the carbs confirmed that nothing was getting 
through. I could turn the engine over and over, pump the gas a gazillion 
times, and get nothing. I tried removing and replacing the hose from each 
connector at the carbs and pump, and then making sure that all of the hose 
clamps were tight.. Still the engine wouldn't start. Then, after about 20 
min, I could see some fuel returning to the in-line filter, and the engine 
finally started up, and ran perfectly. Assuming that this was not a problem 
with the fuel pump--which to my knowledge either works or doesn't-- I 
surmised that the fuel lines were getting too hot somewhere, and adjusted 
the length of all the hoses so they weren't directly touching a heat source 
(such as the block, or shrouds/sheet metal) and in the one spot where there 
is still contact (the back edge of the sheet metal covering the stock oil 
cooler) I put a larger diameter hose piece around the fuel line to serve as 
a buffer. All was well until today, when the exact same thing/condition 
occurred! Aside from that single spot of contact with the sheet metal 
covering the stock oil cooler, there is no other contact between the fuel 
lines and heat source(s). I turned the engine over again and again, messed 
with all the hoses (removed/reattached/tightened clamps) to no avail... 
after about 20-25 min, at which point the fuel started flowing again, and 
the engine ran like nothing had happened all the way home.

SO, my questions are

1) Am I correct to diagnose this as classic vapor lock? I ruled out the 
fuel pump because it otherwise works perfectly. Correct assumptions?

2) How could this happen again after readjusting all of the hoses in 
relation to heat sources?

3) Why would this happen even if the lines did touch the block/sheet metal 
directly? On my old motor, the hoses from the pump to the T-splitter and 
then to the carbs virtually laid right on the block, and I'm quite sure the 
in-line filter and/or hose between the pump and filter touched the sheet 
metal above the oil cooler directly, without the extra hose to buffer. 
Plus, in the last year of that motor's life, I got the engine up to 
280-300F every DAY on my short commute before shutting it off, and still 
never had a vapor lock issue... again, with the hoses touching heat sources 
all over the place.

4) Does cloth braided hose stay cooler in the engine compartment than 
non-covered fuel line? The hoses from the pump to the T and then to the 
carbs are cloth braided, but the hose bringing the fuel to the pump (on 
both sides of the in-line filter) is the larger-diameter 
non-braided/covered hose. This is the one that comes closest to the heat 
source at the back of the cooler, and that I have buffered with the 
larger-diameter hose piece. Could this be a/the culprit?

5) If this is vapor lock, does anybody know any quick tricks to release the 
pressure/vapor and get moving again without the requisite 20-30 min wait?

Needless to say, this has temporarily suspended my T3 Nirvana... TIA for 
any advise!!

David Y.
68 Sqbk


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