Engine Performance problem
1991 Buick Lesabre 6 cyl Front Wheel Drive Automatic 109000 miles
Hard to start when damp and cold.
Have replaced plugs and wires.
No error message on the diagnostic tester.
No Service Engine Soon light.
Replaced O2 sensor, checks out with my diagnostic tester, gives a pass signal after engine has ran for about 1 minute and sensor has heated up.
Replaced fuel filter.
Swapped out an ECM from a junk yard 91 Buick lesabre, same exact symptons.
You can hear the fuel pump run for about 2 seconds before starting ( as it should).
Replaced all orings for fuel injectors.
Soaked fuel injector tips in carberator cleaner while replacing orings.
Just failed the maryland emmision inspection for NOx, went from.22GPM in 2006 to recent test of 2.6 GPM. CO went up also from 1.6 to 7.5 GPM ( it passed, limit is 20 GPM in Maryland. HC went up also, , from.06 in 2006 to.89 GPM in 2008 ( passed, limit is 1.0 GPM).
My next step was to replace the ignition cioil and wire harness.
Car actually runs well after starting. Nice acceleration.
If I were to guess, something might be on the edge with air/fuel mixture or timing.
have the same problem?
Sunday, March 16th, 2008 AT 9:10 AM