Classic/Antique Car Repair/Chev fuel pump

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Expert: - 11/18/2008


Question
QUESTION: Should fuel pump pressure drop when engine starts? When key is turned, pressure is about 58 lbs. It drops to about 50 when engine starts. Is that normal?
Thanks

ANSWER: Year, make, and model of the car please.

---------- FOLLOW-UP ----------

QUESTION: It's a 2000 Chev Silverado  K15703 4X4 8 cyl 5.3 liter.
Thanks.  

Answer
The pressure will drop with the engine idling and go up when the engine is not running or you stomp on the go pedal. the fuel pressure regulator reads intake manifold vacuum to help lean out the mixture when the engine is under no load and then richen the mixture by increasing fuel pressure when load is applied.
Brad

Classic/Antique Car Repair

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Brad Sears

Expertise

All automotive including antique and collectible. However if the car has been modified I can only answer in general terms and maybe get you pointed in the right direction.

Experience

Automotive tech instructor. Syndicated auto columnist 1970's though the early 1990's. Syndicated auto radio talk show, Ask Brad About cars, CBS Radio 70's through 90's TV Show "Last Chance Garage" 1980's PBS-TV syndicated. Auto instructor for the following companies: Fram Autolyte Holly Carter AMF Ford Motor University Of Conn Blue Hills Technical School Sugar River Technical Center Grew up in a family garage in Needham Mass and turned wrenches from the age of 14.

Publications
Manchester Union Leader, Nashua Telegraph, Motor Service Magazine, Yankee Magazine, Popular Mechanics (Saturday Mechanic early 80's), Los Angeles Times, New York Times, and lots more.

Education/Credentials
More than I care to remember. Basically Franklin Technical Institute in Boston, Northeastern University, Fitchburg State Teachers College, Tufts University, and a lot of factory schools along the way.

Awards and Honors
Moto Award winner. And much more.

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