Question-------------------------
Followup To
Question -
I have a 1987 honda accord lxi. The car has a low, rough idle. Sometimes the idle will drop very low and the raise up again, once and a while the idle will drop so low the car will stop running. I have been told the egr system is causing the problem. But i have repalced the egr value and fuel regultor and the problem still continued. No one seems to know how to fix it
Answer -
David,
Before I get too deep into the diagnosis, I want you to check the PCV valve. They are known to blow out on these cars. What you need to do is run the car at idle. Get a pair of needle nose pliers and pinch the PCV hose off. You will find this hose behind the center of the valve cover between the intake manifold. Right in the center if the engine between the #2 and #3 cylinders. Just pinch the hose off. If the car runs smooth at this point, you found the problem! If not, I will need as much information as you can give me. List the tests you have performed, what else has been done to try and fix the problem, when does this happen, when did it start.
Good luck.
Thank you for responding so quikly. I found the PCV valve and replaced it. The valve was pluged with engine oil. After I replaced the valve the car ran great. but after it cooled down it went back to normal and idled rough.
I then checked the air filter which was covered with oil. I replaced that and traced the oil trail through the air intake system all the way to the fuel intection unit. I belive this is the porblem but how is oil leaving the valve cover and entering the air intake. the only thing i could see would be through the rubber hose that connects the valve cover and the air intake. I would appreciate any advice you could provide Thanks, David.
AnswerDavid,
Ok. First off as you guessed, you should not have all that oil in your air filter. It sounds like you may have a broken or worn piston rings. You guessed right about the oil entering the air filer. It is going thru the PCV hose. What it is is called blow-by. You see, oil is getting past your rings on the pistons , entering your crankcase, and then its vented to the air filter thru the pcv valve. (hence the name positive crankcase venalation)The only way to fix this is rebuild the engine.
The rough idle is either from low compression or fouled spark plugs. (Possibly other things too)
I would take it to a shop and have them do a leak down test and compression test. You need to start there.
Good luck
