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Reduced Power Indicator - 2004 Grand Prix 3.8 Supercharged

F

FSmith

New member
Interesting issue - I have searched through the forums but did not see one issue that was exactly like the issue I am experiencing and it may not even be an issue at all but the computer doing exactly what it is designed to do.

The car has 94K miles - I am the second owner. Since I purchased the car - I have driven it approx. 3500 miles - 95% of these miles on the interstate at 65 to 75 MPH daily. The car is stone stock - no changes at all and I always run 93 octane gas. The engine performs excellent 99% of the time. Accelerates well, and maintains on cruise control 70 mph no problem. What is puzzling is when I have to accelerate to 80 to pass another car - maybe a quick burst that may last 15 to 30 seconds.... the first acceleration pass - all is good... however - if within a few minutes - I need to accelerate again - I do not just "punch it" but feed the power in slowly... the engine will fall flat and the "reduced power" light will start flashing. I have to reduce speed, and withing 30 seconds or a minute the light will stop flashing and normal engine performance will return. I do realize the reduction in the power output is a safety measure - too hot, low oil pressure, etc. of which these conditions are not existing. This is annoying as I have had to shut down and fall back in line on the interstate as I cannot pass the intended vehicle ahead of me.

Now - there are no check engine codes. I have a decent piece of equipment to scan for codes - no codes present.
Oil is fresh, air filter is good, etc, I would appreciate any information as the issue or non-issue if it actually is doing the right thing.

Since this car still has the original plastic LIM gasket - cold it be leaking Dex Cool into the intake and affecting the the engine under hard acceleration?
 


give it a tune up. im sure its never had one.

and what lights flashing? the check engine light? if so that multiple misfires cause by needing a tune up or the cat is clogged up.
 
the little engine silhouette in the display panel is the one that flashes off and on ...
and I never thought about a new set of spark plugs, wires, etc. and it probably has not ever had a tune up - seriously the previous owner was a lady librarian.
 
Also check the lines that run to the MAP sensor behind the supercharger follow them around and make sure they are not cracked or broken. If the MAP sensor gets a bad reading because the line has a crack or leak on it it will send it into reduced power. You will have a connection under the snout that goes to a T then splits and goes to the boost bypass valve then to the bypass itself, and that is on the front of the engine. The other end of the T goes to the Map sensor. There are 2 sensors that are identical, one is the MAP and the other without the line on it is the barometric pressure sensor.

Jeff
 


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