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I have a 2002 Buick LeSabre with the 3800 II engine. Engine will will start, then immediately die. You can rev the engine at start instead of letting it idle and it will rev and then die after about 10 seconds. Removed the MAF sensor and no difference. Does this mean that the MAF sensor is bad? Seems most forums i’ve Looked at say that is one of the parts that is to be replaced. The part is expensive and so changing just to eliminate it as a possibility of being the problem seems a waste. Is there a way to test it? Shou;d I go to a “pick a part” place and pull one off another engine?
 

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When MAF is removed, the PCM uses "last good values" that are stored.
If you unplugged the MAF, and no difference, your problem likely is elsewhere.

Check the fuel pressure regulator at the fuel rail. Unplug vacuum line and check for dripping gas or smell.

Check fuel pressure at the schraeder valve. Should be around 50 lbs.

When did you last change the fuel filter?

best of Luck..........
 

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Another thing to do when checking for fuel in the vacuum line for the regulator is to look into the vacuum hose pipe on the regulator body using a flash light. While doing this, shake the front of the car and watch for any FUEL SLOSH inside the vacuum tube where the hose would be attached(do this with engine off). If there's a leak in the regulator, you would be able to see fuel slosh inside the tube going into the regulator body. Generally, when a regulator goes bad, it's severe enough stalling occurs pretty easy. On case where the leak is somewhat minimal, it will only show up/stall once in a while. If the regulator leak is more severe, it will stall at stops or when coasting with no throttle applied. Check this before doing any other changes......

Jake

PS, the o2 sensor would not cause a cold engine start up issue. But, it wouldn't hurt to try unplugging it and try a cold start to see if there's any changes. However, this will set a code and bring on the check engine light. DO YOU HAVE A CHECK ENGINE LITE ON??? If there is a code in the computer(PCM), what is the number for the code??? While we are speaking about this, I would suggest a good diagnostic scan to see what the data is doing during this problem. GOOD LUCK..........
 
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