Throttle body

Asked by May 03, 2017 at 02:49 PM about the 1990 GMC Sierra 1500 C1500 SLE Standard Cab LB

Question type: Maintenance & Repair

I'm working on a 1990 gmc 1500 it runs good but
when it looses vacuum starts,to run really rough

1 Answer

22,135

You checked engine vacuum pressure? Is the intake leaking air? Is you brake booster good? Most time a vac leak causes high idle but if you are loosing enough to not have enough. There is many reasons it could run rough, from misfiring to throttle body/IAC dirty or bad loose electrical connections.

1 of 1 people found this helpful.

Your Answer

GMC Sierra 1500 Experts

  • #1
    dragonflyoffshore
    Reputation
    5,530
  • #2
    John Saffrahn
    Reputation
    3,820
  • #3
    Glenn Clingenpeel
    Reputation
    3,570
View All

Related Models For Sale

Used Ford F-150
3,062 Great Deals out of 230,783 listings starting at $1,300
Used Chevrolet Camaro
390 Great Deals out of 31,491 listings starting at $3,000
Used Ford Mustang
348 Great Deals out of 41,846 listings starting at $1,488

Used Cars For Sale

2018 GMC Sierra 1500 For Sale
9 Great Deals out of 30,014 listings starting at $22,639
2017 GMC Sierra 1500 For Sale
80 Great Deals out of 5,697 listings starting at $20,999
2016 GMC Sierra 1500 For Sale
112 Great Deals out of 3,463 listings starting at $14,500
2015 GMC Sierra 1500 For Sale
180 Great Deals out of 5,679 listings starting at $13,500
2014 GMC Sierra 1500 For Sale
191 Great Deals out of 4,261 listings starting at $9,995

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.