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MAP Sensor

2K views 9 replies 6 participants last post by  chevracing 
#1 ·
Hello All. I have a 1988 Olds Cutlass Ciera with a 2.8L. My dad and I need to change the MAP Sensor out. Does anyone know how hard/easy this? Also, the reason we are doing this is because sometimes on cold starts it won't run unless you pump the gas. It does it while running but will clear up when you get the revs up. It only does it for about 1 min. and then its fine. Will the MAP sensor fix the problem? We are 99% sure it will, so is the mechanic at my work, but is there anything else that could cause this problem? Thanks in advance.
 
#3 ·
I would concentrate on looking at the IAC {Idle Air Controller} which should flare up upon start up and hold the idle at a higher speed for a 30 seconds or so. You should not have to give the engine any throttle during start up. Not to say this is the problem, but it sounds suspiciously so.
 
#5 ·
A mechanic at my work ran codes and the MAP Sensor is the thing he is suspecting. There were like 5 other codes but he didn't think anything of them. He told me there is something else (like the ECM or something like that) but I checked it and it was fine.
 
#6 ·
If you have multiple codes, you must isolate variables to pinpoint the problem. Do not guess by buying a bunch of parts. Scan the car, and write down the codes that are present. If some of the codes are historical codes, I would clear them by unhooking the battery cable for a couple of minutes, then let the vehicle run for a while to get the hard (current) codes from the ecm.
 
#7 ·
Last night I switched out the M.A.P. Sensor. It seemed to help but now today hit. It seems to be still be gettting worse. :confused: I will talk to my mechanic tonight about the Idle Air Controller. I'm going to replace the bad fuel filter too. I want to do that battery trick to "reset" the codes too. Anyway I'll keep y'all posted. Thanks for all the help.
 
#8 ·
Does sound alot more like the IAC is not sweeping properly (due to gummed up movement or electrical falure)... As for the codes only the first code and possibly the second are worth the time of checking out... Most of the time its the first code the rest are just a result of the real problem... Also with that old of a car you might just have a intermitant connection problem with is sometimes very hard to find... Without the engine running take the time to go to each plug and disconnect it, inspect for corrosion and reconnect them... You might even cure your problem...?
 
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