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Jerry
Jerry, Master Mechanic
Category: Buick
Satisfied Customers: 17219
Experience:  ASE Master tech. 30+ years mechanic, shop forman, service manager
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1990 Buick Century Custom: v..stalls when you accelerate..fuel filter

Customer Question

My 1990 Buick Century Custom, 3300 v-6, will idle but stalls when you accelerate. I changed the fuel filter and 2 vacuum lines with no results.
Submitted: 5 years ago.
Category: Buick
Expert:  Jerry replied 5 years ago.

Hello and welcome to Just answer.com, Super mechanic here. Please DON’T hit accept until you are completely satisfied with the answer. If you have any further questions on it please just ask. About your vehicle.

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You will want to check the fuel pressure to see if it is too low.

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If ok, then you will want to see if the exhaust system is clogged. You can have an exhaust back pressure test done on it most muffler shops can do that with a back pressure tester.

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Specifications

FUEL PRESSURE:

Ignition ON Engine OFF 40.5 to 47.0 psi
With Regulator Vacuum Applied [1] 3.0 - 10.0 psi Less than Ignition ON Engine OFF

REMARKS:
[1]
May be checked with either of the following methods.

  • With Pressure Regulator Vacuum Line Attached at normal idle speed.
  • Ignition ON Engine OFF with 10 Inches Of Vacuum Applied To The Pressure Regulator.

graphic

Customer: replied 5 years ago.
Not sure I have the skill or tools to ck fuel pressure - replaced in tank fuel pump a year ago, so I'm wondering if the pump would work intermittedly or just not work at all. It will idle, and will accellerate fine at first, then quickly will only idle (stalls if throttle is depressed). I guess I'm wondering how it can run at all if it has a bad fuel pump / pressure problem.

If there is a clog in the exhaust, would it be in the catylitic converter? Examining the exhaust I found the pipe behind the cat. conv. twists freely - weld or clamp is no good.
Would removing the cat. conv. be an easy test?
Expert:  Jerry replied 5 years ago.
Yes, you will want to know what the fuel pressure is, it could be the pump shutting off intermitently. A good test for the exhaust is to take the 02 sensor out of the pipe and see if it gets more power that way.
Customer: replied 5 years ago.
Where is the 02 sensor located at - the exhaust manifold or lower on the pipe somewhere?
Expert:  Jerry replied 5 years ago.
graphic




Rear Of Engine, On Exhaust Manifold

Applicable to: Century w/V6



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Customer: replied 5 years ago.
Well it's not exhaust, so I guess that leaves fuel pressure. Can you tell me where the fuel pump is located at?
Expert:  Jerry replied 5 years ago.
The fuel pump is in the gas tank.



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