Will not stay running at first start?

1999 BUICK LESABRE

170,000 MILES • 3.8L • V6 • 2WD • AUTOMATIC

EARL91

MEMBER
88 POSTS

I have replaced the fuel pump, fuel sending unit, fuel filter. PCV valve mass air flow sensor, ignition module, plugs and wires. When first start, I have to pump the throttle for about a minute so it will stay running.

Nov 11, 2022 at 10:49 PM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi,

When you say it's necessary to pump the gas, do you mean after it already started or while cranking? Also, have you checked the engine coolant temperature sensor's signal via a scan tool? If that is off, the air-fuel mixture will be off as well.

One other thought, have you checked for engine vacuum leaks, and does the check engine light stay on while the engine is running?

Let me know.

Joe

Nov 12, 2022 at 1:32 PM

EARL91

MEMBER
88 POSTS

I came to find out I have a bad EGR valve and o2 sensor. Which in turn has been causing my stalling issue and rough idle. I have unplugged my EGR until I can afford to replace it.

Nov 13, 2022 at 6:24 AM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi,

Thanks for the update. I'm glad to know you found the issue. I don't know if you need them or not, but I attached the directions for replacing the EGR on your vehicle. I hope they help.

Take care,

Joe

See pic below.

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Nov 13, 2022 at 8:50 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.