i got a 87 iroc 350,5 speed... put new motor in ran awesome, then later check engine light is on,,reads map sensor or vacum leak..well i checked all over and no leaks , then i went to change map sensor and ther is no map sensor any ware ....were is it suppose to be?? well anyway car ran allright after that just problems starting it ..now it dont start hardly at all,it seams like it is starving for fuel, i put a throttle sensor on it it made it worse when it does run it wont rev past 3500... can anybody help there is a wire plug in by the drivers side header near the firewall could this be wher the map sensor was??? wher do i hook up my vacum..........thanks any help is appreciated

 

Are you sure it's a MAP sensor code

Map sensors are located from the factory on the upper plenum on the intake, passenger side, near the rear of the plenum. However, I don't think that the MAF setups had a MAP sensor at all.

If you have a vacuum leak, spray carb cleaner around the intake with the engine running. When you get close to the leak, the engine will "stumble" at idle as it sucks in the carb cleaner. Easiest way I've found to pinpoint them. You said it has a new engine, how old is the fuel filter?

 

What is the code that it is posting? MAP sensors were not on any of the 85-89 TPI systems (that I know of) more than likely you have something else going on. His method of finding vacuum leaks works quite well. Try to post up the SES code so we can better help you with your problem.

 

the code its flashing is 33....according to the book at autozone that is a map sensor and or a vacum leak.. ive tried the carb cleaner trick with no luck....is there another sensor i should check ??? i also replaced the maf sensor on bottom of the plenum...