On my 1984 Toyota pickup, 22R engine, the float gas level is right where it
should be (middle of sight glass) when it's
running and right after shutting the engine off. But after a few hours, and
especially overnight, the gas level drops
down to the bottom of the sight glass, just barely visible. At that point it
takes 15-20 turns to get the engine to
start. Once it starts and runs, then it will always start on the first or
second turn until that point that it's been
shut off for a while.
I checked the vent control device and it's plunger is free and working correctly
as far as I can tell. I'm not sure
where else to look...I don't see any evidence of gas getting into the oil but
if that happens, what path would it take
to get there? This happens everytime I park the car for more than an hour or
two and I use the car every day...so if
gas was getting into the oil I think I'd notice the oil level rising and the oil
smelling of gas, which I don't.
Any ideas about this...I had the same problem on my 1976 Datsun pickup except it
took 3 days to reach this point and
then it wouldn't start without starting fluid. Couldn't figure that out either.
The gas is going to evaporate in the bowl, especailly when engine is
hot. Your problem is not that but rather fuel supply because the fuel
in bowl should be quickly replaced on startup. Check fuel pump, filter
and maybe for a a restriction or vacum leak on suction side of fuel
line slowing the draw of fuel from tank.
Thanks for the idea, I'll check the fuel pressure and the filter. But if there
was a problem in this area, wouldn't it
show up as a lack of power under acceleration or at freeway speeds? And is it
really normal for 1/4-1/2" of gas to
evaporate in the float chamber...an hour after shutting the engine off, when it
is the hottest, the engine still starts
up easily. So the evaporation must be happening after the engine has cooled.
I agree that the fuel pump should be filling up the chamber immediately but
here's another thing that's puzzling me:
after the float gas level has gone down, it takes about 20 pumps to get the car
to start. When you look down the
primary venturi, there is an orfice (jet) that just barely dribbles out gas with
each pump. Should this jet be showing
a good strong squirt...or is it designed to barely dribble. On the cars I'm
familiar with, old VW's, the accelerator
pump nozzle gives a very good squirt with each pump. I wonder if part of the
problem is in the accelerator pump
area...or does this 22R carburator rely on another source of gas for it's
Let me know what you think about this.
This is possible but even still a good fuel system with a good pump
would replace it quickly when cranking. He could add a eletronic boost
pump to switch on before starting to fill bowl quickly if he does not
find anything else wrong. If you do this you want a pump that is about
6 or 7 PSI max. I suspect the fuel pump is weak and while it can keep
up with driveing demands it has little reserve and takes time to fill
bowl. Also, it does no good to pump the gas pedal when bowl is empty.
Wait a few seconds for bowl to start filling during crank than pump
it. Try this, crank it for 4 or 5 seconds and do nothing, pause for a
few seconds and then pump gas and crank it.
Yes it should. Sounds like the accelerator pump is not working properly.
It would be a good time to get a carb kit and overhaul the carb. Be sure to
clean the passages and blow them out with compressed air.
.or is it designed to barely dribble. On the cars I'm familiar with, old
VW's, the accelerator
I checked the fuel pump and it's putting out 6 psi. I also tried some starting
fluid and the engine started right up,
and the float chamber filled up to the correct level very quickly. That leaves
a bad accelerator pump diaphram or the
accelerator pump jet plugged up as the problem. My air compressor isn't hooked
up so I'll have to figure out a way to
blow out the jet but I'll bet it's one of these two items. And my original
concern about the float gas level may have
been misguided. Someone on another forum told me that he checked his sight
glass and his gas level was lower than mine
and his engine starts right up everytime.
I'm trying to find out which nozzle/jet/orfice discharges from the accelerator
pump into the venturi. I think it's the
one that shows dribbling gas when I activate the throttle arm (where the
accelerator cable attaches)...it's a brass
piece just barely sticking out into the venturi and it's in the front (front of
car) wall of the venturi. You can see
it looking down into the primary throat. My two manuals show all the carb
components but leave out the standard
horizontal drawing that shows the passageways connecting between different parts
of the carburetor. Does anyone know of
a web site that would have that drawing for the 1984 Toyota pickup, 22R engine.
I have a manual that goes up the 1983
and has this drawing but it's the wrong carburetor.
I want to blow this jet out and I'm not sure if it comes directly from the
accelerator pump...can I just remove the
accelerator pump diaphragm and blow through the little hole?
Been there, done that. I have an '82 with likely a very similar Aisin carb.
Find a NAPA and get THEIR aerosol carb cleaner, two bucks. Best cleaner
I've ever used, a total carb rebuild with it and an old toothbrush. Anyway
attach the little tube and squirt it through the little hole and see where
it comes out. Do those on top of the carb body too and see where they go.
Watch your eyes!
BTW, NAPA sells an accel. pump singly should you not be up for a rebuild.
(Wish'd I'd never dis-assembled the choke assy or throttle linkage, there
was no need to). my 2 cents...
I tried blowing through the accel pump passages with carb cleaner, the larger of
the two holes goes to the float chamber
and was clear, but the smaller hole (on the left side) didn't seem to be clear
and I didn't get anything to blow through
and out into the primary venturi. If there's a check valve it should allow
pressure to go through towards the
venturi...but that's something I don't know. In fact, I'm still not sure where
that passageway leads...do you remember
from when you did it. The diaphragm looked old and a bit stiff, but I couldn't
see any holes in it.
So my quest goes on, to find a diagram of the carburetor passageways...anyone
out there have one? Does anyone know what
supplies the first charge of fuel that actually starts the engine...which
nozzle/jet in the venturi does it come out of
and does it come from the accelerator pump or from somewhere else? You wouldn't
think this information would be so hard
Its been more than 2 years but I don't remember any check balls. The stiff
diaphram may depress and make a pump okay but the light spring may not have
enough oomph to return it back to position, if all the way . Do remember
mine being really stiff, NAPA $8, but a rebuild kit was only $30 out the
door. With that said...
Try from the top of the carb the same cleaning method on all the
holes...will PM you...
Sorry, tried to PM with the rebuild drawing but server setting wouldn't let
me for some reason.
I don't work for napa but was recommended their cleaner, robin's egg blue
spray can was only 2 bucks. Used 1 can for rebuild and bought another later
just to have. it has xylene and acetone in it. also had Gunk on hand but
it hardly did a thing except stink. Had real good luck on general cleaning
but gave it good blasts on those passages. The truck sat for 2 years and
the carb just filled with deposits, nothing worked and of course no fuel, no
Now at zero degrees on a cold morning it starts in 2 revolutions. I now use
two fuel filters inline, the old standard cylinder type and did away with
the expensive stock type.
Honestly you might try a rebuild kit. The choke, and butterflys dont need
to be messed with. In hindsight I wouldn't chang the float needle SEAT
either. You really want at the main body to do a good cleaning of the ports
and there are some more ports on the underside of the main body.The carb
might seem intimidating by looking at the drawing, but looking at the actual
parts involved it really is quite simple. Will attach the repair sheet.
446k. Will note that these carbs seem sensitive to float levels, just
change the needle? Mine sits right at the top of the sight glass. After
trial and error that's where it wants it. My mileage is 2mpg better than
before and starts like a dream. And it is normal for boil-off/evaporization
to happen if left sitting for a few days and will have to crank for a few
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