rough idle at low rpm

[raiderdaniel]

My 92 Miata was running rough intermitently at low rpm. I was told it was the coil pack, so I replaced the coil pack and the spark plugs, but now it seems worse! I dont have much experience with foreign cars, any suggestions?

[Mx5guy]

Wow! no repplies at all seems like this forum is lacking knowledgeable miata guys keeping that in mind I'll stay close by, It seems somebody made u waste Money on a coil pack. I,ll say is way simpler check for vaccum leaks specially around the throttle and EGR valve, check for possible craked or loose hoses. That should do it. God bless.

[Turbodog97]

Try running some sea foam through the system.

[Acro_Raptor]

Sounds like your idle is out of adjustment, or a sticky ISC valve. Check these threads for info.

http://www.miata.net/garage/isc.html

[CaseyJones797]

Check for loose\broken\split vacuum hoses. Make sure the spark plugs and wires are in good shape. Replace if they have a lot of miles on them. Check the air intake tube (the long one that crosses in front of the engine from the air filter box). Make sure it is not split and that the joints are tight. The coil pack probably did not need to be replaced for what you were experiencing. Clean the cam sensor. Make sure the air flow meter is clean (special cleaner required for this). That's a good start and will kill a good Saturday morning.