MAP Sensor Problems

BRYANSZOLLOSI

MEMBER
1992 CHEVROLET CAVALIER
6 CYL
FWD
AUTOMATIC
250,000 MILES

I drive a 1992 Chevrolet Cavalier 3.1L V6 RS Wagon, and it has been giving me a lot of problems lately. It idles smooth but when it gets up to any speed it loses a significant amount of power and runs really rough. Now I've run the diagnostic scan and it's telling me that the MAP sensor voltage is too high. Just for background I've replaced the alternator, EGR valve, TCC solenoid, PCV valve, and I checked the vacuum line running to the sensor for leaks. A new MAP sensor made no difference either. What is wrong with my car?

5 Replies

SATURNTECH9

MECHANIC
30,869 POSTS

What is the exact code number you have?Lets start there.

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Monday, April 19th, 2021 AT 11:04 AM

BRYANSZOLLOSI

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3 POSTS

The error code number it's giving me is 33

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Monday, April 19th, 2021 AT 11:04 AM

SATURNTECH9

MECHANIC
30,869 POSTS

I posted a wire diagram and the trouble tree for code 33 let me know what you find.

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Monday, April 19th, 2021 AT 11:04 AM

BRYANSZOLLOSI

MEMBER
3 POSTS

Sorry I took so long, things have been hectic. I went through all the wires since I don't have the proper tools to run the diagnostics you said, and as a result I didn't find any broken connections, at least where I could reach. I've also noticed that my car goes through antifreeze pretty quickly.

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Monday, April 19th, 2021 AT 11:04 AM

SATURNTECH9

MECHANIC
30,869 POSTS

The antifreeze loss is a different problem all together your best bet on that one is rent a coolant pressure tester and pump up the system and look for a leak. As far as your map sensor code your going to have to get a scan tool that can read obd1 live engine data to trouble shoot it correctly with the info I gave you.