.....if it starts at all. :o(
1999 Buick Regal GSX 3800 V6 SuperCharged. 148,000 miles
Car is in excellent condition. Well maintained. Always 93 octane gas. Only Mods: Mobil 1 synthetic oil and K&N drop in air filter. Very fast car! About 3 months ago I noticed if you started it up after letting it set all day and tried to go full throttle (boost) out of the parking lot it would fall on it's face. (Dead spot) No problems after I drive it a few miles. Monday it wouldn't start. I could smell gas so I thought it was flooded. I tried starting it after 2 hours but it still wouldn't start. The next day it fired right up but after 2 or 3 minutes it started to run rough and had black ( soot) smoke coming out of the tail pipes. It quit running so I let it sit for awhile and started it again. It idled great for 10 minutes. I turned it off and it wouldn't start. Today it started but it ran very rough. Idle fluctuated from 600 rpm to 1900 rpm. Up and down surging. I let it set awhile and it started and seemed fine. It finally quit.
I checked and it has spark.
Can hear fuel pump running. I checked the fuel pressure 49-50 psi key on / 39-40 psi run.
I replaced all 6 spark plugs.
1 can of fuel injection cleaner.
New fuel pump resistor.
New fuel filter.
NOTHING HELPED! Still the same problem. :o(
TIA,Mike
It's probably the mass airflow sensor and/or oxygen sensors.
I figured it would be. I had an 86 LeSabre for about 5 years with the 3.8, which is an ancestor of the 3800 motor you have. I replaced the MAF probably 4-5 times over the period I owned the car. They're a weak point in that series of GM V6 motors and tend to break every so often. And if you're the kind of guy who likes to steam clean his motor (like I do), wrap the MAF thoroughly in a trash bag. Any water gets on it and you can pretty much assume it will conk out in a week or so.
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Thanks for the reply. I changed both O2 sensors and still no change. Car starts and runs fine for about 2 or 3 minutes and then starts surging with black smoke coming out tail pipes.
It was the MAF! Thanks!
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