Trouble Starting/ Engine dies once in awhile while stopped at a light

Asked by Mar 11, 2016 at 03:53 PM about the 1999 GMC Sierra 1500

Question type: Maintenance & Repair

My truck will start just fine after sitting for awhile (i.e. overnight), but if the engine is shut off and I try to start it back up in 5 minutes, 10 minutes, 30 minutes later, its hard to start and takes a little (5 sec).  Always starts eventually. Also, when I am stopped at a light, I will feel the truck is about to die, but if I let off the brake it will catch itself and be fine.  Any ideas on what it could be...I'm thinking fuel pump, but after looking at some of the answers on the site to similar questions, it seems like that's not always the case. Also its not the battery...its brand new.

2 Answers

20

If you let off the brake and it acts differently, then maybe you have a vacuum leak in your brake booster line.

76,215

Hard starting is an indication of leaky fuel injectors, spider lines, and fuel regulator. What size is the motor? So what you do is hook up a fuel pressure gauge to the Schrader valve, then just cycle the key on off until it builds up pressure, should be 56 to 63 lbs. then let it sit with the key off, now just watch the gauge for 3 minutes, the fuel pressure should not drop off more than 5 lbs. If it does, then the injector assembly would need to be replaced as a unit.

Your Answer

GMC Sierra 1500 Experts

  • #1
    dragonflyoffshore
    Reputation
    5,450
  • #2
    John Saffrahn
    Reputation
    3,780
  • #3
    Glenn Clingenpeel
    Reputation
    3,470
View All

Related Models For Sale

Used Chevrolet Silverado 1500
2,619 Great Deals out of 174,525 listings starting at $1,000
Used Ford F-150
3,159 Great Deals out of 219,406 listings starting at $700
Used Toyota Tundra
704 Great Deals out of 34,615 listings starting at $1,500
Used Toyota Tacoma
697 Great Deals out of 45,610 listings starting at $2,500
Used Dodge Ram 1500
443 Great Deals out of 11,110 listings starting at $2,000
Used Ford F-250 Super Duty
395 Great Deals out of 48,801 listings starting at $1,899
Used Chevrolet Tahoe
827 Great Deals out of 41,817 listings starting at $1,995
Used GMC Yukon
608 Great Deals out of 20,973 listings starting at $2,695
Used Cadillac Escalade
261 Great Deals out of 11,930 listings starting at $1,200
Used Chevrolet Camaro
437 Great Deals out of 31,440 listings starting at $1,450

Used Cars For Sale

2018 GMC Sierra 1500 For Sale
25,680 listings starting at $24,499
2017 GMC Sierra 1500 For Sale
64 Great Deals out of 11,618 listings starting at $20,369
2016 GMC Sierra 1500 For Sale
161 Great Deals out of 4,044 listings starting at $16,404
2015 GMC Sierra 1500 For Sale
209 Great Deals out of 5,588 listings starting at $14,995
2014 GMC Sierra 1500 For Sale
208 Great Deals out of 4,929 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.