1991 Buick Lesabre Hard to start when damp and cold.

Tiny
SSSMJD
  • MEMBER
  • 1991 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 109,000 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.

Your thoughts?

thanks,
scott
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Sunday, March 16th, 2008 AT 9:10 AM

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Tiny
MERLIN2021
  • EXPERT
Check the ECT ohms should change as it warms up. If you can scan values, before you start it the first time in the am, hook up scanner, scan with key in on, not running, and look at ECT and IAT temp, they should be within 5 degrees of each other.
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Sunday, March 16th, 2008 AT 9:34 AM
Tiny
BMRFIXIT
  • EXPERT
Check the coil
use a water spray bottle and spray the coil watch it arc
replace the coil
NOX check EGR
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Sunday, March 16th, 2008 AT 10:44 AM

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