my 85 suffers from oscillating while idleing. It through a MAP code. What is the map and would it effect the idleing. It also has a leaky intake gasket is that most likely what is causing my car to oscilate. I thought that 85s didnt have MAP. It through a code 33 and 34 and the shop sheet also says MAP code. But im kinda thinkin i may have done that because i unplugged the MAF to see if it would fix the oscillating problem which it didnt and forgot to reset the codes. The vette does idle high on start up and then work down in bout 10 secs where as with the MAF unplugged it immidiatly goes to 800 rpm. thanks

 

the map code number is used as either a map or maf depending on the year and application.
If you car is an 85, it is a maf code, if you have a 90, it is a map code.
You have a maf code, and it indicates that the maf is either incorrect on it's calculation, or the circuit card is malfunctioning somehow or the wire connector either has a bad wire or corrosion etc.

 

Thanks to many hours of research on this thread and the help of Agent 86's wisdom in many related responses from him to other forum members, I can suggest a few things to try.

First, I hope you have a good Volt meter, a few things you need to check, first is power to your MAF, ground the green wire to the engine, and you should see .5V. If you have that, read on. If not, you have a broken wire and need to trace, your FSM will help. If you do not have one, search the threads here using "code 33" or "code 34" to get you started. I will caution you , the 85 is a little different than the other years in respect to the MAF circuits..... We 85 owners do not have a burnoff relay... keep that in mind.

So, I've been down this path on my 85, I was throwing the same codes. Through much research, I learned the 85's have a seperate MAF burnoff module, not a relay, which is quite expensive and difficult to get to. So to rule this out, my first step was to replace the MAF relay and Fuel pump relay, clear codes and restart. Still showed codes......

Then I replaced the MAF with a refurbished unit from NAPA $189, cleared codes, no codes YEAH!!! ran great for 5 minutes, sputtered and spit, ses light comes on, codes returned

SO, I was frusterated, as I replaced both the MAF and MAF relay and fuel pump relays (fuel pump relay powers the Burn off module), DID NOT FIX ANYTHING... However, I checked my wires going into my connectors, as heat and age shrink back the insulation and caused a short , I repaired with shrinktube and a heatgun, took a while but figured better to do it right and only once.... well worth the effort!!

SO I returned the MAF to Napa, as the short from the wiring going into the relay had claimed its life, they exchanged it at no charge, replaced it, been running with no codes and perfect ever since.

Hope this helps...........