where did the gas go?

[PROMISQS@domain.elided]

Date: Thu, 13 May 1999 11:35:13 -0700
From: "John Hofstetter" <hofs@domain.elided>
Subject: Lack of gas

Michael and others,

Michael, I never doubted after the facts seemed to be in, that your
problem was fuel pump. Others, including me, have had somewhat similar
fuel pump problems. At one time I had a check valve just after my fuel
pump that wouldn't allow the gas back any farther than the valve. I
had a hell of a time finding that check valve, but it turned out there
was one made for diesel applications. 

There is also no doubt that some people, for example Bill in Tulare
who had the really new looking Terra, have a problem with the fuel
disappearing from the fuel bowl. In most cases I know of, this only
happens after sitting for a while, in some cases a matter of hours, in
others a matter of days. I'm sure that in the case of some carbs,
particularly Thermoquads, the gas is leaking out of the bowls and into
the manifold. In other cases, this doesn't seem possible, and I looked
at evaporation as a possible contributor to these empty bowls. It
can't all be evaporation, of course, because as you pointed out, the
evaporation from engine heat is a short term process, and again most
empty bowls appear after a matter of hours.



To John H and others re "were does the gas go" From Bill and the 76 Terra
- 

Tulare 99, here we are 12 mi south of Tulare in the gas station  filling up 
on coffee, and left the 76 Terra 304/Holly 2210 at idle. Wife in truck and I 
am about 30 ft away when the engine just shuts off! I yell at the wife, "did 
you shut the truck off?" She says "nope, just quit by it self." No amount of 
cranking would even make it start, not even catch. Had lots a gas, and 
figured maybe it had got so warm under the hood that it vapor locked. 
Egad…1:30am…wife getting edgey……..tow to the motel……at least the tow truck 
was a great looking 98 International. Next day, on goes new fuel filter, and 
used old hoses again…….wrong….I think.
Drove truck around Tulare the next day no problems. Get up next day to go 
over to the fair grounds …. Same problem.  No start, not even a catch. Now 
this is a cold start,  no vapor lock, where did the gas go????? IMHO the gas 
drains back somewhere, somehow. Got some help from a local garage (Saturday 
mourning in Tulare no less) and he suggested that the fuel filter was a good 
idea but did I change the fuel hose on either side? (Think Tom M posted 
something on this.)  He explains that,  however fuel hose is constructed he 
swears that when it gets old it can leak air in when no pump pressure is 
present, and seal up under pressure. On goes new hose, clamps, and real 
tight. Problem solved, off to the fairgrounds!! Good all day……until Sunday 
afternoon at Micky D's. Sitting in the lot , engine at idle and it dies. 
Again crank and not a whimper from the engine. Now however I have the wife 
spray carb cleaner in carb while I crank, and after about 5 seconds of 
constant spraying  and running on cleaner, she catches and runs on gas again. 
Now the funny thing is it only, and I mean only does this at idle when the 
truck is stopped for about 2 min. Drive truck for a couple weeks after 
Western Regionals, and careful to not let it sit at idle. Now truck starts 
every morning runs fine…..just don't let it sit at idle for very long. Get 
stuck in traffic or waiting for the left turn signal, and here I am blipping 
the throttle like crazy trying to keep the truck off of idle. Well, this all 
is fine until  finally on the 07 May  I am blasting over the Coronado Bay 
Bridge at 50 mph in heavy traffic, and wham…….the engine decides to go into 
its strangle mode at speed this time. Downshift, dump the clutch, and again 
she roars to life as I roar to the nearest exit. Ending of story is the fact 
that I found out the the fuel pump can take an amazingly long time to fail, 
and mine failed at 37k miles. $25.00 for a Airtex replacement from Carquest 
and we are back to normal.

Bill in Coronado
67 800
73 Scout II
76 Terra