Extreme lean condition - 87 22R carburetter

[imo...@msn.com]

My 87 22R w/carb exhibits an extremely lean condition. Here's the
long story. I installed a rebuilt carb years ago due to the original
carb being all carbonized and gummed up and not allowing the
secondary to open. Symptoms were very poor gas mileage and black
smoke out of the exhaust After the rebuilt carb installation the
truck never ran right. Symptoms were: NO power during normal
acceleration; pushing the accelerator further made the truck go
SLOWER. When pumping the pedal with little pumps of the pedal
(squirting gas into the primary), I could feel surges of acceleration
with each little pump. As expected, no amount of idle screw
adjustment had any effect. Basically the truck was almost undrivable
and the carb vendor showed NO concern. Out of desperation I rigged a
short piece of thick wire to hang down into the secondary and keep the
plate from opening more than 13/32in. With that setup it would drive
acceptably but mileage suffered and reading the plugs showed the
mixture to be rich. So I removed the vacuum cap on the upper-most
capped port of the three capped ports on the passenger side of the
carb. The mileage improved a little (18mpg) and the plugs looked
better. I have been running it like this for a couple of years. But
recently it's been stalling while idling and backfiring during
accelerating. The secondary was beginning to get sticky. So just
yesterday I installed a new rebuilt carb and I was hoping that the new
unmodified carb might be the answer. No luck; the lean condition
problem remains.

I will accept any and all diagnostic suggestions.

[cl...@snyder.on.ca]

You need to make 100% sure you don't have any vacuum leaks, and that
you DO have the right carb. The 22R engine was not known for carb
problems, on the whole. IF you are SURE you have no leaks,and have the
right carb, you need to check the number on the primary and secondary
main jets, and then obtain a set of larger jets. IIRC Holley jets fit
- cannot remember from what carb - but I THINK it is the ones from the
holley single barrel carb used on Dodge slant six and AMC engines - if
you can't get spare Toyota ones. I have drilled jets in the past with
good success - but you want a fair number of off-sized spares if you
go that way. The primary main is likely about 2 sizes small for ideal
driveability, from past experience.
My suspiscion is you have a 20R carb if it is behaving as badly as you
say.

[som...@some.domain]

main was fussy about the filters. if i remember, there are two, one in the
lines near the carb and one on the frame.

[som...@some.domain]

er, it's mine not main. sleudian flip.

[cl...@snyder.on.ca]

The filters will cause problems at speed and under load - and a
second or two after hitting the gas. - but a good idea to check fuel
flow and pressure to be safe.

[som...@some.domain]

exactly, listen to the man.

[Den]

> main was fussy about the filters.  if i remember, there are two, one in the
> lines near the carb and one on the frame.

You can assume that the truck is maintained properly, including the
fuel filters.

[som...@some.domain]

In article <c65c1ca5-6251-49c8...@q24g2000vby.googlegroups.com>, Den <imo...@msn.com> wrote:
>
>> main was fussy about the filters. =A0if i remember, there are two, one in=

> the
>> lines near the carb and one on the frame.
>
>You can assume that the truck is maintained properly, including the
>fuel filters.
>
>

i never assume that. i always check first, not because i don't trust the
owner's abilities but because i want to be sure.
it doesn't take long and it;s something to take off the checklist.

[Den]

> My suspiscion is you have a 20R carb if it is behaving as badly as you

> say.-

Both replacement carbs were/are the correct carb, identical to the
original.

[cl...@snyder.on.ca]

Are they jetted the same???
There were at least 2 calibrations for standard tranny and 2 for
automatic 2 wheel drive - possibly 2 more for 4 wheel drive - and 2
more for the Celica and Corona Mark 2.

[cl...@snyder.on.ca]

ALWAYS check fuel delivery flow and pressure before condeming a
carburetor. You could have a bad filter, a bad pump,a blocked pickk-up
sock or a fuel pickup drawing air - or a collapsed fuel line (rubber)
or piched line (steel). A flow and pressure test will rule out ALL of
them.

[som...@some.domain]

yes, listen to da man, he be knowin'.

[Monroe]

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