On a 2002 Buick LeSabre, if I unplug the iac can I drive the car...it does not stall

SOURCE: buick lesabre nightmare

Need to get a scan tool and look at the data stream while it is running for alot more info.Also any trouble codes.Sounds like initially,the engine isn't getting any fuel.I would have a pressure gauge connected to the fuel rail on the engine,so i could monitor the fuel pressure while all this is going on.Items to look at on the data stream would be timing,what timing is the PCM commanding for the engine.Also,have you checked for continuos power feed to the coils during this no start condition,and fire at the plugs while cranking.You could possibly still have spark,but maybe it is extremely weak?I have seen bad ignition switches cause weird problems before too.Many things power up through the ignition switch,just a thought.Have also seen bad PCM's cause strange problems..38 volts is a little on the low side for GM.Usually see those at,at least .50 and up,and rise steadily while pressing the throttle,up to just under 5.0 volts.Potentiometer with 5 volt supply.Vacuum leak can be checked with engine running at a steady idle speed,spray brake cleaner all around the intake manifold and listen for engine speed change.

SOURCE: buick lesabre no start

You have eliminated most possiblites so you have eliminated me spending all that money i figured out because of rotten egg smell i have determined my cat converter is plugged so i am going to cut it out and replace if nessasary if engine no longer bogs my problem is exactly like yours but mine is intermintent but now it has become extremly bad and its running to rich burning your eyes rich so i hope this solution has helped you in any way Thank you

SOURCE: 97 buick lesabre 3.8 Idles rough and stalls out.

Fuel injectors go bad on these engines, you can find re manned ones for 30 bucks. If you have an engine light on get that read. Change your coil/wires/plugs also. Is the lower intake manifold gasket leaking coolant yet? You may want to get that replaced also. Check the TPS too (throttle positioning sensor) those will also cause your engine to act up

SOURCE: 97 buick lesabre 3.8 Idles rough and stalls out.

ignition system not operating properly ,or intake air leak ...crank engine get a can of staring fluid spray around the intake if the motor idles up you got a leak hope this helps

Greg Bernett

• 2993 Answers
• Posted on Sep 13, 2010

SOURCE: 1995 buick lesabre 3.8 turns

Replace the fuel pump...if you have already, then replace your fuel pressure regulator.