Rough Idle

[Mike Moyer]

My 93 has a rough idle. I have replaced plugs, and have installed a K&N air filter. Other than the idle problem it seems to run fine. I was told by someone to clean the throttle body. When I looked in the Haynes manual it said DO NOT clean. Need some help please.

 

[BGN]

Mike,

I'm not sure why the Haynes manual says that.I have a 1991 and every once and a while I take the hose off leading to the throttle body and spray in some Prestone Throttle Body Cleaner. I've been doing it for years and
it hasn't seemed to harm it one bit. I think Haynes may be referring to the coating inside the throttle body, I guess there is a chance that some chemicals might remove it but the Prestone stuff says its coating safe.

You might also trying cleaning your MAS, see the details at http://www.4x4central.com/tips.htm#mas

Good Luck,

Barry

 

[CHH777]

I had the same problem. The Haynes manual says not to clean because at the time of print there were no O2 sensor safe cleaners on the market. Now there are several.

Try removing and cleaning the mass air sensor, the throttle body and idle air control valve first. Also check all vacuum lines for leaks.

If this still doesn't fix the problem perform a compression check to see if you have a head gasket leak.

Good luck...