Im having a few issues with my '85 and its really driving me nuts trying to figure this out. Here are the symptoms: When I was driving on the highway I noticed that somehow I had lost some power. My RPM's would not go above 2000 and it started to backfire. When I gave it gas at half throttle it bogged down really bad and I got the SES light. Pulled the codes when I got home and got: Mass Air, Knock Sensor, and EGR (which is always with me) code #'s 22,32,33,34. I replaced the following: Throttle Body (52mm), New Mass Air sensor (Film Type), IAC valve (Was sticking), & Bypassed coolant at TB. I unhooked the knock sensor and drove for a while and it seemed to resolve the bogging problem but not for long. Now Im hearing a tapping sound like lifter tap in the engine bay. The bogging down thing has to be fixed. Any ideas on what went south? Help on the matter would be great. Thanks!!!

 

Guessing you all ready checked for vacuum leaks...they are great at setting a 24 and 34 code and engine will bog down if run at all
If you have had the value covers off ...2 possible leaks spots are near alt at the rubber hoses then follow the steel pipe back to rear injectors small rubber there also.
pass side has one spot to leak at pcv but rare.
Does the engine run smooth at idle or run a minute or 2 then die..vac leak..
Clean the MAF 4 wire plug in. Be sure to clear codes every time you do something unplug/check and plug back. reset TPS .54 and the IAC its listed in here someplacecode 34 with a 22 or even 24 is sensers saying hey gas pedal is pushed but no air in coming in and 24 will pop in if this is true and car isn't moving per what tps/maf think. code 32 EGR again vac leak at its hose?

Good reading on TPI http://www.corvetteforums.com/m_37283/tm.htm

Just my 2 cents others will jump in and give a better way/place to look

My 85 only has the problems I cause or that *(%$ antenna issues. kvette89 didn't leave me anything to do on mine when I bought it so I have to find things to do it