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: 99 buick Lesabre
hey thanks for bringing me up to speed. ive been working on many other problems but with your great explanation i remember.
we need to check the compression on that cyl. and compare it to the compression on 2 other cylinders your choice.
but before you do this get a can of carb cleaner . and with the car idling spray around the intake manifold in the area of #6 cyl. what we are looking for is a small vacuum leak that would also act like this. with the engine idling and spraying around the intake the engines idle sould not change and if it does when you spray you have an intake leaking.
let me know how it turns out.
later
paul
SOURCE: 1999 Buick Regal GSX won't stay running......
It's probably the mass airflow sensor and/or oxygen sensors.
SOURCE: My 1998 Buick LeSabre has a misfire on cylinder
Hi, I would check for a vacume leak around your intake manifold #1 cylinder runner. You can check by using a stethescope with a small piece of brake line in the end of the hose or spraying propane around the intake. If you hit a vacume leak the RPM will drop. Vacume leakes normaly cause a higher RPM at idle.
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