corona stops when passing to drive

[tipatalon]

hi i'm new here, great site by the way, i have a 1969 corona who needs bit work and the problem is when i start the engine it has rough idle and when i want to pass to drive it stops if i don't press on the gas. do you guys could help me with this one, it's a downdraft carburetor not very familiar with these ones

[tipatalon]

i've search and can't seem to find it, is there an explosion view of the carburetor on the web. motor is a 3R with aisin carb thanks

[AlaricD]

You might suspect the carburetor, but this vehicle probably has the old points and condensor igntion, so it could also be a problem with the dwell angle, or the points just have pitting or corrosion and need to be filed a little bit (but once you file them, you really need to check the dwell angle).

For this vehicle, you will need a timing light, a dwell meter, and a Chilton or Haynes guide.

Unless you know the carburetor has been tampered with, or that the float(s) have holes in them or are stuck, don't mess with it until you've set the dwell and timing. The carb is usually the last thing you need to touch!

Also, you may want to disconnect and reconnect the wires to the ignition coil and the spark plug wires. Do the plug wires one at a time so you don't get the firing order wrong, and be careful to remove them by holding the boot rather than pulling the wires directly. Do that on each end of the cable, as well to ensure they are reseated properly and any corrosion film has been broken.

[verlaryder]

Could be a fuel or ignition problem. To rule out ignition, you first need to tune up the motor to factory specs with regard to spark plug condition and gap, point condition and dwell angle and ignition timing. Also, engine valve clearances need to be adjusted to factory specs.

[AlaricD]

Originally Posted by verlaryder

To rule out ignition, you first need to tune up the motor to factory specs with regard to ... point condition and dwell angle and ignition timing.

So that's a second for my diagnosis on your points and timing.

Don't even mess with the valves unless you're ready to replace the valve cover gasket.

[tipatalon]

thanks guys, will have a timing light this week end, and will search about dwell angle not quite sure of that. does you guys bother with this carbs or just put weber carb for more reliability thanks again

[AlaricD]

Originally Posted by tipatalon

thanks guys, will have a timing light this week end, and will search about dwell angle not quite sure of that.

Dwell angle is the amount of degrees of distributor rotation that the points stay closed. When it's off, the timing is off. Also, it affects the strength of the spark (if the dwell angle is too low, the coil won't build up a strong enough magnetic field, resulting in a weak spark).

[Carl H]

Originally Posted by tipatalon

hi i'm new here, great site by the way, i have a 1969 corona who needs bit work and the problem is when i start the engine it has rough idle and when i want to pass to drive it stops if i don't press on the gas. do you guys could help me with this one, it's a downdraft carburetor not very familiar with these ones

Your carb will need work, there is a main and secondary as well as idle and power valve and float level that affect mixture. Get a new carb and jet kit so you will have the parts and directions to rework the carb.

The Keystar # is K11-121A for my 69 Corona 1900 3RC.

I have to set the float level to make the fuel height a little on the low side of the fuel height glass and run the timing approx 5 degrees retarded from stock setting. Cleaning and setting the points will help, but there is a lot to check on carb , too. I also use an inline filter before the fuel pump as the jets get dirt in them and the car runs poorly if you don't keep dirt out!

The stock carb is quite a lovely pc. and quite large. The motors easily run up to the redline of 4600 RPMs and do 85 mph. mine gets in the 25 mpg area. I heard they will run up to 100 mph, but I'm not pushing into the red zone and wearing my 3RC out early. 85 is good enough for me.

Be sure to use GL 4 spec gear oil in the manual transmission. I use Redline MLT and it's shifting better than ever.

[tipatalon]

thanks everybody

[AlaricD]

Have you gotten the problem resolved?

[tipatalon]

nope not yet but i had good info for now, searching for time right now.. this week-end will be checking timing with a friend, i will give feedback

[tipatalon]

timing is ok, it's definetely the carb when at idle it's very rough and when cruising but when the pedal is depress to the floor the engine seems to be breathing again like in 69 and the car drive smooth but if i release pedal the car shut off right away! i took the carb off and will clean it tonight and hope it will help.

[tipatalon]

wow man, you're really a strange dude...