18R-C wont idle

[dan_ta22]

Hi guys,

I have a 18R-C that wont idle after it starts to warm up. It will rev with no load but will then not idle and eventually stall.

This car had been sitting for 3yrs not running so Ive replaced the points, dizzy cap, rotor, spark plugs, leads, coil, oil filter, fuel filer, thermostat all oils and coolant.

Taken the carby apart and cleaned it as it was gummed up and put a new gasket kit through it. All the timing has been set correctly.

Initially it would start first thing and idle away fine then when it wamred up it would stutter on idle then stall. Now it will only idle for a min then will stall. It will still rev fine with no load though.

According to the temp guage the water temp has never got real hot but the engine gets very hot quickly and Im starting to wonder if maybe some oil galleries are blocked or not or in fact if its slightly seized.

Any help is greatly appreciated as Ive tried everything I can think of.

Cheers,
Dan

[Dazza]

Sounds like you have a blocked idle jet in the carby causing it to not idle properly. Try unscrewing the idle cut solenoid and giving it a quick blow through with compressed air. You could also try winding out the idle mixture screw a bit to see if it loosens up whatever is in there. Carbies usually get a fair buildup of scale in them from sitting for a long while which is hard to remove with a quick cleanup. Now that it has fuel in it again the scale and crap will start to loosen up and can block small jets like your idle jet.
The water passages in the head could be blocked with rust from sitting or it could be the impellor on the waterpump has rusted away from sitting causing it to get hot quick

[dan_ta22]

Thanks Dazza,

I may have to clean the idle fuel cut solenoid again as it may be blocked from sitting for a while.

Found out the thermostat was completely rusted shut but didnt register hot on the temp guage which we have tested to be working. Probably since there was no water flow there was no heat transfer from the motor to the water therefore misleading me with the temp guage. It now seems I may have done a headgasket now so Im pulling the head off now.

Ahh old motors...

[Dazza]

If you are taking the head off it might pay to check the valve guides for wear and replace the valve stem seals. The rocker arms wear on the shaft that they pivot on too so it might be an idea to check them as well.