1994 Buick Lesabre hesitation and jerking

1994 BUICK LESABRE
90,000 MILES • 6 CYL • 2WD • AUTOMATIC
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PHCARVER
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I experienced intermittent hesitation and jerking mainly under acceleration and also at idle. Mechanic found a code for the EGR valve. We replaced it. The problem went away for awhile, but is back with a vengeance and worse than ever. I have run 44K to clean out deposits. What the mechanic is now telling me is that the EGR valve is opening to 25% and staying open. When the wires are disconnected it closes back again and the engine smooths out. I am now being told that I probably have a bad ECM. With the expense of an ECM, I am hesitant to replace it since the problem wasn't fixed with their last expesive suggestion.
May 18, 2009 at 11:17 AM
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DOCFIXIT
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Hi
They maybe right it is a Digital EGR and is controled by ECM. Need a Tech1 or tester capable of cycling EGR to test. But if you can disconnect term and it idles and runs smooth. Then ECM is very much suspect.
Hope this helps
Thanks for donate
May 18, 2009 at 12:09 PM
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PHCARVER
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Docfixit. thanks. I unplugged the EGR valve and the problem is still there, but not as bad. It gets worse as I go up through the gears and am at low RPM's. Now the mechanic is telling me that he believes it may just be excessive carbon buildup and i should get a full fuel system service. does this hold any merit?
May 29, 2009 at 11:28 AM
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DOCFIXIT
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Yes pulling EGr and decarboning passage ways good idea. Also clean throttle body and MAF.
Good luck Hope it runs smooth
May 29, 2009 at 1:56 PM