why does my truck shut off when idleing

Asked by Sep 19, 2012 at 02:58 AM about the 2003 Chevrolet Silverado 1500 LS Short Bed 4WD

Question type: Maintenance & Repair

when pressure is applied to the gas pedal, it runs fine but as soon as i take my foot off it starts to bogg down and shuts off. check engine light is not on and it now has trouble starting up

1 Answer

35,515

May be a vacuum leak a bad idle air control or a bad fuel pressure regulator. Since it won't idle it will be hard to check the idle vacuum. Start with the fuel pressure regulator. You will need a fuel pressure tester and a vacuum gun. Hook up the fuel pressure tester and turn the key on. Pressure should be around 60ish PSI, apply 15-20 inches of vaccum to the pressure regulator. The regulator should hold that vacuum till you let it off, and the fuel pressure should drop to 40-45 PSI. If it doesn't drop then the regulator is flooding the engine at idle. Replace it. If that tests good then pull out the idle air control and give it a good cleaning with carb cleaner and check for movement, reinstall and check how it idles. If it still idles bad then get a vacuum diagram and one by one remove the vacuum lines from the manifold, plug the hole with your finger, and have a friend start the truck. STAY CLEAR OF MOVING PARTS. Wear short sleeves no baggy cloths ties or necklaces tie up long hair if applicable. If one of them being removed allows the truck to idle then find the bad spot in the line or bad part and repair it. If neither of these work then the problem is quite possible a leak at the manifold somewhere or a burnt valve an injector stuck open and the list guess on. Try these easier steps first and let me know how it goes.

4 of 4 people found this helpful.

Your Answer

Chevrolet Silverado 1500 Experts

  • #1
    John Carson
    Reputation
    2,740
  • #2
    Rowefast
    Reputation
    2,020
  • #3
    Andrew Olsen
    Reputation
    1,730
View All

Related Models For Sale

Used GMC Sierra 1500
1,137 Great Deals out of 65,382 listings starting at $1,995
Used Ford F-150
2,775 Great Deals out of 211,556 listings starting at $1,400
Used Chevrolet Silverado 2500HD
326 Great Deals out of 30,652 listings starting at $3,500
Used Dodge Ram 1500
415 Great Deals out of 10,795 listings starting at $1,499
Used Toyota Tundra
594 Great Deals out of 35,250 listings starting at $2,900
Used Toyota Tacoma
659 Great Deals out of 45,760 listings starting at $2,700
Used Chevrolet Tahoe
782 Great Deals out of 42,012 listings starting at $1,980
Used Chevrolet Colorado
323 Great Deals out of 36,446 listings starting at $1,995
Used Ford F-250 Super Duty
332 Great Deals out of 47,501 listings starting at $1,899
Used Chevrolet Camaro
443 Great Deals out of 31,342 listings starting at $3,550
Used Chevrolet Silverado 2500
6 Great Deals out of 209 listings starting at $4,495
Used Chevrolet Silverado 1500HD
7 Great Deals out of 272 listings starting at $3,450
Used GMC Sierra 2500HD
97 Great Deals out of 14,271 listings starting at $2,799
Used Dodge Ram 2500
173 Great Deals out of 5,237 listings starting at $2,500

Used Cars For Sale

2018 Chevrolet Silverado 1500 For Sale
6 Great Deals out of 71,583 listings starting at $22,270
2017 Chevrolet Silverado 1500 For Sale
172 Great Deals out of 40,168 listings starting at $18,490
2016 Chevrolet Silverado 1500 For Sale
254 Great Deals out of 6,962 listings starting at $16,182
2015 Chevrolet Silverado 1500 For Sale
448 Great Deals out of 12,001 listings starting at $12,950
2014 Chevrolet Silverado 1500 For Sale
426 Great Deals out of 12,685 listings starting at $9,900

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.