87 Accord DX Running Rich

[jzdude]

I have an 87 Accord DX. The car has been running rich lately, evidence from I only gets around 19-20mpg, I smell a little gas, and a little black smoke coming from the tailpipe. The car runs ok, but struggles to accelerate like from 30-50 mph. Past 50 mph it accelerates great.

I was wondering if I should spray some carb cleaner. In the carb, I see 2 big holes: one has a choke plate and the other doesn't. Do I spray everywhere or one of those holes?

Also, I haven't changed the fuel filter for a long time. Could that be a problem causing the car to run rich?

Another probable cause was I just adjusted my valve clearances and I adjusted them in the tightest specifications.

[HLW]

The 2 holes are the primary and secondary barrels of your carb. The one with the choke plate is the primary. The secoindary only opens under heavy throtle. spraying carb cleaner in either will not likely resolve your rich Air/Fuel mix. The A/F mix is controlled by the computer that controls the vacuum switches in the black box on the right side of the fire wall.

Running ruch can be caused by a bar O2 sensor, a carb that needs to be rebuilt, vacuum leaks, bad vacuum switches or a bad computer.

First check for vacuum leaks, then check for vacuum from the switches in the black box by connecting a vac gage to the lines comming form the black box. Then remove the O2 sensor from the exhaust manifold and see if it has alot of carbon (black) on it. If it has a lot of carbon on it, it should be replaced.

[Dr_Snooz]

I'd suspect that the needle valves are leaking.

[honda crew]

My '88 accord lx does the same thing, I thought the throttle was sticky, or it needed a carb cleaning, or a new fuel filter. I thought maybe a K&N high performance air filter would do the trick.

[Martinsmith]

I'd suspect that the fuel fillter are leaking.

[g.frost]

Check that choke is fully open when warmed up.
Check float bowl level (sight glass).