4k Using Too Much Fuel!!

[ke70dave]

hey fellas i need some ideas on my poor little 4k.

 

now not only does my 4k go as fast as a rock, it uses stacks of fuel!!

 

by stacks i mean 10$ (so like 8L) gives me around 60k's before the fuel light turns on

 

ok specs of the engine

 

-150psi all 4 cylinders

-3k carby, so no emissions stuff

-new sparkplugs a few months ago along with a new coil

-new fuel filter and air filter a fair while ago, could prolly do a with a new air filter

 

the engine runs perfectly fine, but just uses so much fuel :D

 

i have played with the mixture screw, i basically just screwed it IN till it ran like crap, and screwed it out a little (just at idle) is this a good thing to do?

 

any help would be greatly appreciated.

[bLinded_]

Hey,

 

My crappy, old 4K with a 32/36 weber on it gets around 9-10km/L so yours does seem to be chewing alot of fuel for a stock carby. This might sound obvious, but did you check the fuel lines and tank for leaks? My sisters rolla was using alot of fuel at one stage and it turned out that there was a little crack in the fuel return line which was leaking fuel. Might be something as little as that. That's all I can suggest. I'm sure that someone on here with a lot more knowledge with these engines will be able to provide further technical reasons for what may cause excessive fuel comsumption. Good luck with it, hope you find the problem soon.

 

-Alex

[ke70dave]

hey mate thanks for the reply, thats one thing i havent looked at. i have noticed a slight fuel smell about my engine bay..might be something to look into

[7shades]

Blinded just triggered a memory... I've actually had perished return lines as well... not major squirties all over the bay, but the hoses were cracked pretty bad and soaked with fuel after every drive.

 

Give all the lines a good blow back into the tank with compressed air too... might be a restriction in the return.

[ke70dave]

ahh yeah thats a good point, ill get the compressor goin and give it a blast, i havent looked at my rubber fuel lines, but thats another option.

 

one thing i have noticed is that if i leave the engine idling for aaagess, it does start to over fuel i think...burbles and carries in untill you give it a rev up the street. so i dunno what that means...

[old corolla bloke]

one thing i have noticed is that if i leave the engine idling for aaagess, it does start to over fuel i think...burbles and carries in untill you give it a rev up the street. so i dunno what that means...

 

it is possible it may be rich on idle causing the miss at idle or could be oil fouling the plugs.

 

also try this fuel saving technique.......put a 50 mm block under the accelerator pedal

 

just joking there but really try to examine your driving style to ascertain wether you are using the accelerator a bit more open than it needs be. after a few years in the carby game it became common to see people looking to save fuel. when every thing was done that was possible to have the car run perfect it still used more fuel than their mates car,it was at these times I would go to the bench and show the the latest in fuel saving technology.......a 50mm piece of jarrah.

 

have you checked

 

ignition components and timing

 

are the tappets properly set? pay attention to the exhaust ones

 

is the air filter dirty

 

make sure the choke is not sticking

 

I hope this helps or gives food for though

 

regards

 

brian

 

old corolla bloke

[coln72]

needle and seat sticking open?????? that would cause it to fuel up at idle.

[ke70dave]

hey thanks for the replys guys.

 

old corolla bloke -->

 

i must admit i drive like a grandma most of the time, barely rev over like 3.5k. (you prolly think I'm lying, but I'm not). i find the 4k to be extremely slow, and that it needs a fair bit of accelerator to get it going sometimes, even just to get into gaps in traffic. so i guess i may use a bit to much acceleration, maybe my engine is lacking power because of some problem?

 

(I'm not trying to sound like a lil punk trying to get 400hp from his 4k, but this engine struggles to spin the wheels in the wet with 195's is completely hopeless at drifting, pretty much just bogs down as soon as you give it load..is this normal for a 4k? with my decent suspension i would have thought it would spin wheels enough to have fun, by the way all these "tests" were carried out on the skidpan)

 

ignition components are all fine as far as i can see, i have timing set to 10deg BTDC, i havent even looked at the tapets, i checked air filter and it apperas to be ok, although i might get a new one next time I'm at the shops, the choke isnt sticking, it did a few months ago but i fixed that

 

coln72

 

I'm not sure if the needle and seat are sticking open, i wouldn't really know how to check, it would involve pulling carby apart I'm assuming?

 

 

I'm considering doing a minor tune up on the thing, getting some new spark plugs, air filter, and goin crazy with carburetta cleaner, reckon that would help?

[coln72]

should be able to see if there is any fuel dribbling down the throat of the carby when it is at idle (or not running at all) with the aircleaner removed.

[ROLLLA]

have you ever thought that using the 3k carby might be ya problem with power at to me the 4k carby looks alot bigger. Also a 3k carby is much older therefore more prone to wear which could cause overguelling siyuations. I recently bought a secondhand carby from the wreckers because i had some similar problems and the replacement seems to have no dramas at all. One thing i learnt was to never touch the little screw things on the carby because i could never get the thing running right after i did with the old one.

 

cheers

 

Pat

[ke70dave]

yeah the reason i got a 3k carby was cause the guy before me had ripped all the emissions stuff off the 4k carby, and just blanked off all the pipes. and to cut a long story short it barely ran.

 

i read that a 3k carby was exactly the same as a 4k carby except it had no emissions stuff. can someone confirm this?

 

i would use a 4k carby (as i have 2 of them) but i don't have all the emissions stuff to go with it, all the pipes and little valve things. so there are vacume leaks galor, and i dunno which ones you can block off and which ones you can keep etc etc

[bLinded_]

yeah the reason i got a 3k carby was cause the guy before me had ripped all the emissions stuff off the 4k carby, and just blanked off all the pipes. and to cut a long story short it barely ran.

 

i read that a 3k carby was exactly the same as a 4k carby except it had no emissions stuff. can someone confirm this?

 

i would use a 4k carby (as i have 2 of them) but i don't have all the emissions stuff to go with it, all the pipes and little valve things. so there are vacume leaks galor, and i dunno which ones you can block off and which ones you can keep etc etc

 

Hey mate,

 

Where abouts do you live? I am in Wagga Wagga(NSW) and I Have a 4K carbie with ALL emmisions gear attatched to it if you need that. It was running on my 4K but was replaced by a 32/36 weber. All it needs is a good clean out with some carbie cleaner and it'll be as good as new. If you are interested in it, send me a PM. For a small price I think I could probably part with it. I'll even include the airfilter box and a filter :D

 

-Alex

[ke70dave]

hey man thanks heaps for your offer, but I'm in Brisbane unfortunately so might be a little difficult.

[bLinded_]

No worries mate. I'm sure that there will be one available to you that is in your area. If not, there should be a wreckers with one. Good luck with it all.

 

-Alex

[Smithius]

just shove a weber on it. the standard carbys suck.

 

i had the same problem with my 4k carby and a 3k carby that i put on my ke55.

 

solution was to ditch the stock peices of crap and put on a 32/36.

 

more power for around the same economy.

 

or try a gemi carby. chep from wreckers and no need for the adaptor plate. just read the instructions that are on this site about fitting and you should be right.

 

 

Cheer

Matthew