I've got a 91 LX Accord. Sometimes while idling, my rpms will intermitently drop about 500 rpms, return to normal, then go back up, drop again, etc. I notice it most while warming up, but also after driving before pulling the key. I asked a friend, he pointed to a part on the front of the PFI, said it was adjustable.

My question is, how do I adjust it?

 

..he was probably talking about the idle cable, and.... I may not sound very clear so.... do this... ask someone to accelerate the car and whatch the little thing go back and then forth (..where your friend pointed)... ...yup... that's the one you are looking for.... ...there's a little screw, which adjusts how much the car will idle with.... it can be very low... or higher (not recommended though)... ...the... adjust to what you find mostly like the normal idle.... and .... that should be it!!!

 

Egr valves is pulling in air you need to change it asap or it will get worse

 

Do not do what gianinline suggests. He doesn't know what he's talking about. The other guy may be right. It could be the EGR valve. You could try removing it and cleaning it out along with the ports and the screen. You might want to have another gasket on hand in case you tear it.


Modified by amckee at 5:35 AM 10/3/2005

 

Before you do anything, unplug the IAC valve and set your idle speed at about 500 to 600 RPM. The adjustment screw is under the three or four vacuum lines on the passenger side of the throttle body. Plug the connector back in and see if your problem is still there. Kill the engine and remove the back up fuse to clear the code that is set. Sometimes when the idle is set too high, the IAC can't settle the idle down because it was designed to increase air flow, not reign it in from to much idle screw bleed. I would also guess that if your intake hasn't had the EGR ports cleaned (by removal, not something added to your gas) that they are plugged and it wouldn't make one bit of difference if the EGR valve was stuck wide open. On a car that is 14 years old, It would be a good idea to buy new orings and seals for all of the control valves on the throttle body and the EGR valve and replace them. I assure you, they are all hard as a rock and flat now, not round. They are cheap ,but, you will probably have to get the dealer to order them. Clean the inside of all of the valves with a methylene chloride based brake cleaner like Gumout. If you see cxarbon build up on the EGR ports of the intake, then you can bet that the four little holes that open into each intake port are clogged and will have to be mechanicaly cleaned. No spray alone will do the job.

 

My car did this, I actually eventually replaced the distributor and the problem went away....runs like new. Pull the cap and rotor, then grab the end of the distributor shaft and yank'er back and forth. If there's play, you'll probably need a new one. The slop in the rotor when it's running causes intermittent loss of spark, there by misfiring and causing the rough idle. Contacts in the cap-housing probably look like s*#t.....

Could be the ignitor module. Ignitor problem symptoms are loss of power under acceleration, tach needle jumping.....