my 4k in my ke70 idles pretty rough sometimes, to the point that the whole car shakes lol

So far ive cleaned out the carb, got the carb tuned by a mechanic, checked for vaccuum leaks (couldnt find anything), checked the timing and i installed a new manifold gasket, none of these things improved the problem.

Also, when i press the throttle pedal, it hesitates a bit and then picks up...

Does anyone have suggestions? 

 

Edited October 7, 20197 yr by matitties

Does it still have the mechanical fuel pump, might be getting weak.

You'll need to find the difference between when it idles well and when it idles roughly.  Is it when its cold? When its hot? After a run? Stopping at traffic lights after crawling around town? Some problems are intermittent, some permanent.

The needle and seat is an intermittent one, sometimes it floods the carb and other times it is fine.

Does it accelerate well once it is going? Give it a good long pull in third gear max throttle up to maybe 5500rpm and instantly put it into neutral and turn off the ignition. Then pull the spark plugs out and see what they look like. Take a photo.

Next time it idles badly, turn it off & pull the plugs out again, take another photo. It may be flooding when it idles badly, so the plugs will be black, or maybe only one plug.

Take the top off the air cleaner and look down the carb. Open the throttle sharply and you should see a jet of petrol from a small brass fitting down the carb throat. If this accelerator pump is not working it will hesitate under throttle.

Plenty to explore.

5 hours ago, LittleRedSpirit said:

Does it still have the mechanical fuel pump, might be getting weak.

yea still has the mechanical pump, how can i test it?

2 hours ago, altezzaclub said:

You'll need to find the difference between when it idles well and when it idles roughly.  Is it when its cold? When its hot? After a run? Stopping at traffic lights after crawling around town? Some problems are intermittent, some permanent.

The needle and seat is an intermittent one, sometimes it floods the carb and other times it is fine.

Does it accelerate well once it is going? Give it a good long pull in third gear max throttle up to maybe 5500rpm and instantly put it into neutral and turn off the ignition. Then pull the spark plugs out and see what they look like. Take a photo.

Next time it idles badly, turn it off & pull the plugs out again, take another photo. It may be flooding when it idles badly, so the plugs will be black, or maybe only one plug.

Take the top off the air cleaner and look down the carb. Open the throttle sharply and you should see a jet of petrol from a small brass fitting down the carb throat. If this accelerator pump is not working it will hesitate under throttle.

Plenty to explore.

the car wont idle without the choke all the way out when its cold, once its warm it idles fine but after driving for a little while it idles rough and sometimes shuts off when i get off the freeway or come to a stop at a traffic light, could it be a piece of rubbish from the tank avoid the needle from seating properly?
it goes perfectly at high rmps, accelerator pump works fine, ill try the third gear pull method, thank you for the tips!

"the car wont idle without the choke all the way out when its cold "

Could be normal or a bit lean, it is a little adjustable.

" once its warm it idles fine "

That's good, mine is like that.

" driving for a little while it idles rough and sometimes shuts off when i get off the freeway or come to a stop at a traffic light "

...and mine does that too!  Once it is really warmed up the idle drops even more and can die when I brake to a stop. If I hold the throttle on a whisker it stabilizes and idles OK.

Well, try the plug check when it dies, that might tell you if its dying from being lean or being rich.