I have a 1986 RS with a 2.8 and it is running rough. I keep getting a code 33? MAP sensor voltage low. Any one know where this is located on the engine? I looked around and can't see it on the firewall. I don't see any vacuum hoses leading to anything that looks like the MAP. Thanks.

Bill

Damn, I'm out of practice. I know that '85-86 2.8Ls originally were designed with a MAF setup, but there was a TSB that converted it over to MAP, when the setup got extremely buggy. Snap a shot of your engine bay, you may still have the original MAF setup.

Mine has the MAF and a MAT but I can't find a MAP. Would it be one or the other? Also, Why would I get a code for a MAP? It is a new computer with an old PROM and ID(?) chip.

After doing a look in my book ,ur Map is located directley behind the alternator below the strut tower brace.Looks like its very close to the heater blower in my book.Ur mat sensor is obviously inside the tubing for the fresh air intake which flops up and down or side ways.I would throw up a pic from my haynes or chiltonsonline but it would not do it justice.They do not show exactly what it looks like other than just a # and lame pic of where it should be http://www.partsamerica.com/ProductDetail.aspx?mfrcode=GPS&mfrpartnumber=77911502&parttype=414&ptset=A this is what u should be looking for .

86 did not have a map sensor. 85.5 and 86 got a maf sensor, 87-88 had both a maf and a map, however there was programming issues and gm swapped to map only (speed dencity update).

code 33 is for map or maf, depending on what the car has.