Map sensor S.D. -Mass Air Same?

bryanrevans

New Member
Sep 10, 2004
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Chicopee,Mass
I got 86 gt.Just put my stock tb and intake off of old 89.Now im getting map sensor code and rich code.Car would not start intil i unplugged map sensor vacuum hose.Finally started but had black smoke and two codes Map and super rich.Would i have excess fuel just from the vacuum being unplugged on map sensor??And is Map sensor for Speed Density and Mass air the same?I know that on some mass air theres no vacuum hose,it just hands there.I nocticed that my 89 had 1 vacuum hole plugged on intake!!!!!!
 
Is the vacuum line removed from the sensor? If not remove it, and plug the line so you don't have a vacuum leak. I forgot to pull the hose off when I converted my '87, and it wouldn't even start. They are different, but either will work on a MAF car.
 
Mine ran with a SD sensor and MAF, with the vacuum line unplugged. I thnk you mean you want to put a MAP sensor from a MAF car into the '86? Then you would have to put a vacuum line to it.

That sensor should not cause problems with idle. The idle is choppy? surges? stalls? It's probably something else like the IAC.
 
What happed was after I put Throttle body,upper intake,lower intake,I.A.C Valve,Egr Valve from a 89 5.0 onto a completely stock Speed Density 86 5.0
I couldnt get it to start.It would turn over strong and hang for a 1\2 second at 1500 rpm.I thought maybe i didnt torq lower intake proper like!!So i scanned for codes and got Map Sensor code.Unplugged the Map Sensor plugg nothing.So next i plugged backin and then unplugged vacuum,Fires right up with super rich condition!!Black smoke idle, arround 800-900 Of course when i scanned codes again I got MAP and rich fuel mixture.I got map code cause no vaccuum, right??????But do I have rich fuel cause of map????On ebay theres a couple of map sensors but 4 mass air cars 91 and 89 5.0 sorry i cant type
 
Is the MAP sensor off of the 89?? Cars equiped with a MAF conversion typically retain the MAP sensor but you're right... they don't have the vac hose hooked up to it. Only the electric side is used and even then I think it's just as a pass through for the convienience of the harnesses. At this point, I'd have to guess that your problem is with either the MAP sensor itself or one or more of your 02 sensors is bad. Either way, they can often be checked out at your local autoparts store. I believe that the part numpers for the MAP sensors are the same, MAF or SD.