1989 Pontiac Lemans Losing Horsepower

1989 PONTIAC LEMANS
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INEEDLEMANSHELP
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Engine Performance problem
1989 Pontiac Lemans 4 cyl Two Wheel Drive Automatic 107K miles

I have absolutely no clue as to why. I just lose horsepower randomly. I've noticed that my temperature gauge refuses to rise very much, the one time it moved up a decent amount she drove great. My mechanic has said that it isn't the thermostat.
He's replaced an O2 sensor, a map sensor, and has greased a some module.
Any clues?
Nov 19, 2008 at 4:44 PM
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LYOKOFREEZE
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Hello there!

I've run into a lot of the same issues. I would check the following:

-Throttle Body
- Make sure it's not clogged
- Run an injector cleaner like Seafoam
- Have the Mechanic rebuild it
- There are other sensors in it to potentially replace
-Vacuum Lines
- I know I've got the same problem right now and we've narrowed it down to a vacuum leak. Have him check ALL lines.

- Question: Are you also having misfire issues also?
Jul 14, 2009 at 1:26 PM