Hilux 4x4 Forum

Hi team, my 1998 Hilux 2.4L PETROL is smelling super super rich when running. Had my mechanic set the carb up but maybe he needed more coffee.
Plugs good, compression good etc etc...can someone guide me on how to set up the mixture (I've had quite a lot of mechanical experience in my youth, even rebuilt motors)

Welcome Tony!

There's not a lot that you can do to the carb itself IRO adjustments. The "adjustment" screw is really just an air screw for idle mixture. Things to look at are float level, auto choke, worn butterfly bushes, vacuum hoses and airflow restriction (air filter element).

There are a number of these threads here, one just has to do a search with key words like "Nikki carb", "22R carb", "2.4 carb" and so on.

Thanks Mud Dog - have checked most of those but just so smelly at idle! I may have to search out my local carb specialist as most young mechanics now haven't even seen a carb!

Has the fuel consumption changed for the worse?

Tony Clendon wrote: ↑Wed Apr 11, 2018 12:24 am Thanks Mud Dog - have checked most of those but just so smelly at idle! I may have to search out my local carb specialist as most young mechanics now haven't even seen a carb!

Is the idle solenoid valve working?

yes it has - fuel economy has got worse that is

As Mud dog says. The mixture adjustment screw is only effective when at idle as it has an influence on the idling circuit. The moment you accelerate the idling circuit effectively falls out of contention and has a very limited effect on the mixture if any. The only real way to lean out a carb is to change the jets. I am assuming that the carb has the orginal sized jets in there in which case it is unlikely that the jets could be part of the problem. Unless someone removed the jets and cleaned them with wire or something that would cause the size of the jets to increase - such as using a thin steel wire to clean the jets. I use an old toothbrush to clean the jets and NEVER stick anything in there that could scratch the surface inside the aperture that could cause the size to increase.

But if the jets are unmolested then the extra fuel is coming from somewhere else such as worn bushes on the butterfly valve or other wear in the carburetor or possibly a damaged/leaking gasket causing fuel to be sucked from the float bowl. a Float level that is too high could also contribute but if I read your post correctly you have already checked that.

I would see if I could get a service kit for the carb, disassemble it, give it a thorough clean, check for wear on all moving parts and bearing surfaces and rebuild it setting the float level to spec and then see what the fuel consumption does.

I think this might be the best bet, carb has probably never been apart. time for some love

You still get Echlin carb kits. Usually your local Indian spares outlet can help. I think Control Instruments is the agents for Echlin.

Jaco, that might help if Tony was in the RSA but he's in New Zealand.

Also get the CO2 settings right at a place that can measure the readings. It is sometimes the culprit for running too rich or too lean as well.

Good luck!

Oops, missed the New Zealand part.... How about a photo of your Hilux Tony?