Questions and Answers

Hyundai Excel Carburetor Problems Q. Hi, I have a 1987 Hyundai Excel GL, 1.5 liter, automatic transmission and carburetor. We bought it for our son to learn on, and also for me to run this summer. We're going to share it for a while. When I bought it, it had a hesitation. I did all of the usual stuff, plugs, cap, rotor, plug wires, oil change.

It runs great when cold, but it runs kind of rough when it gets to operating temperature. Under a normal load, it will buck and hesitate just enough that you feel it when driving. If you give it a little extra throttle, the roughness goes away. I replaced the O2 sensor, engine temperature sensor, thermostat but no affect at all.

The car sat for about 7 months, was started every week while it sat. I guess my question is: does the carburetor sound like it needs to be rebuilt and cleaned up, or do you think it may be something amiss in the carburetor feedback system? I know this may not be near enough info for you to form an opinion, but any help would be appreciated. It seems as if it is running lean, or is fuel starved.

Thanks for any help you can give.
Chris

A. First thing I would do is replace the fuel filter. A partially clogged fuel filter can cause the symptoms you describe. At the very least it will eliminate it as a possibility.

Spray a quick shot of carburetor cleaner into the carburetor while the engine is running. If the idle speed picks up, it is running lean. It could be lean due to a vacuum leak or it needs an adjustment.

If you are sure there are no vacuum leaks, you can try adjusting the fuel mixture. There is a fuel mixture adjusting screw in front of the carburetor. Try turning it out a ¼ turn at a time and driving it.

If adjusting the fuel mixture doesn't help, then the carburetor will have to come off and be cleaned and rebuilt.

If the concealment plug is still on the carburetor, it will have to be drilled out. To do that you'll need to take the carburetor off and drill it out from the bottom.