4k Carb Problems.

[Gareth]

I'm recently having problems with my single carb on my 4k. I recently replaced the cam in the engine with a fast road cam and it was going fine. I got the idle tuned so it was just strugling to stay alive and the car was running fine. I then went and bought myself a 3k-b twin carb which i used to replace my single carb but with huge problems. 1 of the carbs jets wasnt working to i cleaned it out but still the car sounded horrible like it wasnt running on all 4 cylinders so i decided to go back to my single carb. I hooked the carb up as usual but when i started it it didnt seem to run as before. The rev's with my foot flat on the accelerator seemed to just be at 2000rpm. then after about a minute they would catch up go as usual but the car would back fire every time i took it over 3500rpm. anyone got any ideas on what i need to do?

 

thanks

[Taz_Rx]

Checked for vacuum leaks?

[Gareth]

yes i checked for vaccume leaks and it was the gasket from the carb to engine. there are no backfires anymore now but the car is still with foot flat staying at about 2000rpm then after 30 seconds ish it goes all the way and strugles to idle. any more advice? cheers

[RainWarriorDregs]

i'm kinda having this same sort of problem, i just changed my distributor and sparkplugs and did my timing and now it farting and gurbling all over the place. and i can put my foot flat and it takes a few seconds to actually start building revs. i'm thinking my carby is f@$ked or over fueling. going to put another one on this afternoon, see if it does the same thing

[TRD ke70]

check your fuel pump pressure going into the carb, should be about 2-3 psi, then check your float level, next check the power enrichment valve, it's the one that sits in the bottom of the float chamber, this is NOT the main jets.

[RainWarriorDregs]

sooo.... don't wanna hijack, but i'm not sure if OP knows how to do this, but i sure as hell down,

 

how do i check my float level? and what should it be at?

 

same question about the power enrichment valve :)

[Evan G]

don't wanna hijack either but since were on 4k carbs.

 

I'm having a weird problem, when driving steady at 80km i can feel the engine speed fluctuating, its like its speeding up and down when I'm holding my foot steady

 

any ideas?

[TRD ke70]

ok if you don't know how to do this, maybe get a workshop manual to set the float level.

It will also have all the info about the carby in there as well.

 

unfortunately not everything in a car can be done by someone with no training or without the correct information.

Some stuff you just can't explain over forums!

[skidsharpe]

I'm recently having problems with my single carb on my 4k. I recently replaced the cam in the engine with a fast road cam and it was going fine. I got the idle tuned so it was just strugling to stay alive and the car was running fine. I then went and bought myself a 3k-b twin carb which i used to replace my single carb but with huge problems. 1 of the carbs jets wasnt working to i cleaned it out but still the car sounded horrible like it wasnt running on all 4 cylinders so i decided to go back to my single carb. I hooked the carb up as usual but when i started it it didnt seem to run as before. The rev's with my foot flat on the accelerator seemed to just be at 2000rpm. then after about a minute they would catch up go as usual but the car would back fire every time i took it over 3500rpm. anyone got any ideas on what i need to do?

 

thanks

 

Pull the plugs out and see if they are dark or oily. This happened in my bros 4k after he got it tuned because that much fuel was going into the thing..

[RainWarriorDregs]

ok if you don't know how to do this, maybe get a workshop manual to set the float level.

It will also have all the info about the carby in there as well.

 

unfortunately not everything in a car can be done by someone with no training or without the correct information.

Some stuff you just can't explain over forums!

 

 

i've got a workshop manual. i'll have a look. last time i remembr looking in it it didn't have too much good info, its the crappier one of the two, i think its a haynes, not a gregories. or the other way around. not sure.

[Gareth]

Ok cool well i'm going to have a look at the float and check the pressure of the fuel going in this afternoon but i just remembered that origionaly i had a alluminium fuel line going into the carb but have recently changed it to a lot thicker tubed pipe could there be to much fuel going in? should i put a limiter into the fuel line?

 

cheers

[ke7012345946]

Can anybody Tell how to open jammed butterfly and valves on is fine but the large one is jammed any solutions 

[parrot]

That makes no sense. Read it again and correct it with a proper question

[altezzaclub]

"the large one is jammed "

How did you try to make it open? Govt emissions regulations of the 1980s meant that manufacturers moved away from manual twin-choke carbs to vacuum operated secondaries or delay diaphrams or other systems that mean they won't open if you just open the throttle wide open. Even revving the engine with no load will not always open them.

If you had all the linkages disconnected and it was jammed you could expect corrosion and dirt in the axle bush and around the plate edge, usually from sitting on a bench for a decade. The other thing that jams them is being bent or twisted.

Start a new topic for it and give us some photos.