Mechanics

STALLING AND LIMITED SPEED

1979 Mitsubishi Lancer • 78,000 miles

Help me please : (
i'm new here. Im new at cars. I got mine last march
a used mitsubishi lancer colt.
and i'm wondering if someone could help me with my problem.
it runs at most 60 when cold and 80 when the weather is hot.
and it does a quick uhm. Not really a stall. But not strong enough to be a misfire. I don't know what it's called but there's an air burst on my air cleaner

there's this second barrel on my carburetor that's got a double butterfly and the butterfly below opens at 80% throttle but the top one wont budge. Is it normal?
Avatar
Jicary
June 4, 2012.



For backfiring, it could be due to the rich condition, ignition timing too advanced, a poor cylinder, spark plug and/or related components. That would require tests to confirm.


KHLow2008
Jun 10, 2012.
Spark plugs are new.
What does ignition timing mean?
After letting the choke butterfly open. The backfiring reduced. But is still there.
Here are the pictures


Tiny
Jicary
Jun 12, 2012.
Ooopppsss
pictures.
Here.
Sorry there's nothing much to see.
It was night time when I took these


Tiny
Jicary
Jun 12, 2012.
Ignition timing means the time the spark plugs fires. It is adjusted by turning the distributor clockwise or counterclockwise and you use a timing light to check. If contact breaker points are used, the gap clearance would affect the timing. The wider the gap, the more advanced it is.

I don't see any choke plate in the pictures.

The rubber capped plunger at bottom of last picture is the accelerating pmp. Ensure you have a fine spray into the carb at top inner part of carb barrel. If there are none or is too little, you would have hesitation and possibly backfiring as well.


KHLow2008
Jun 12, 2012.
When I press the pump it sprays fine. But the secondary doesn't spray any.
Sorry its the picture, you cant see the plate because it's too dark. Notice the second barrel is dark while the first one, you can see the butterfly(gold). The secondary is closed.
Should both of them spray gas at the same time? Or is it supposed to spray on the secondary only when the second barrel opens?
Ill take new pictures. Those you can see : D


Tiny
Jicary
Jun 14, 2012.
The secondary does not have any accelerating pump functions. Only the primary has it.

I can't seem to be able to see the pictures now as they are not loading correctly. Maybe I will try again later.


KHLow2008
Jun 14, 2012.
Ohh... i thought it's supposed to be pumping as well :D
haha. sorry about that. new knowledge for me.
i forgot to take pictures earlier this day. haven't been able to go to my grandparents house. that's where the car is.
thanks for taking the time to help me with this problem.

here's the picture..
http://cdn.2carpros.com/question_images/34361/large.JPG?1339474936

why does it have an exit when there's no pump action for that barrel?


Tiny
Jicary
Jun 14, 2012.
The accelerating spray is from the side of the barrel. The central venturi for the primary and secondary are for fuel to flow when suction is created by air flowing through it. They do not spray.

I was expecting a big butterfly covering the barrel. Seems it is only for the primary venturi.


KHLow2008
Jun 14, 2012.
I took a video of my carburetor.
I'm gonna upload it later.
I let the choke stay open. I tested and it still backfires every once in a while. The secondary butterfly opens well at 70-80% throttle but I'm still having the backfiring problem.
Also, the engine power is very low. I'm having a hard time with this.


Tiny
Jicary
Jun 15, 2012.
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