89 Accord LX 5-speed, (2.0 Carb.) with 98,000 miles. Car has been running perfect untill 2 days ago. Engine bogs down to 100 - 300 RPM's (and stays there)when at Idle (nutrual)only. Motor also sounds a little rough when it bogs down. When in gear, car drives fine. Spark pluges & Plug wires 2 months old(1000) miles or so. Car maintained very well. Could it be a vacume leak? or something else going out or already out? Engine completely stock, never been modified. Checked my Haynes Mannual, but stumped. Any Suggestions??? Thanks - Ken

 

I would start checking the vacuum hoses of the carb.

 

i have owned an 89 in the past and had similar problems, along with loosing 5th gear turned out i had a cylinder with low compression... hopefully this isnt the problem with yours, like PAhonda suggested check vaccum lines and go from there... possibly check cap and rotor if neither have been changed in quite a while

 

Pretty easy to measure compression, just to rule that out.

 

i would recomend reseting you ecu, you unplug the negative battery cable for about 30 minutes and then reconect it and turn your car on but do NOT hit the gas and let it idle for about 10 minutes without hitting the gas then turn your car off and back on and your ready to go. ive had similar problems with the cars rpms droping so low it almost stalls, i would try this first to see if that will fix your problem

 

A carburator probably cant re-learn the idle-system behavior.