Throttle body

Asked by Indio104 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
59,745

enginecreator answered 7 years ago

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 people found this helpful.
Mark helpful

Your Answer:

Related Questions

Own this car?

Share your experience with others.

1990 GMC Sierra 1500

Write a car review

Review another car

Shortcuts

Search GMC Sierra 1500 Questions

CarGurus Experts

  • #1
    yetilikesbeer
    Reputation
    12,820
  • #2
    dragonflyoffshore
    Reputation
    11,750
  • #3
    John Saffrahn
    Reputation
    11,690
View All

Know more, shop wisely

Search

Related Models For Sale

Used Ford F-150
6,322 Great Deals out of 167,617 listings starting at $1,500

Used Cars for Sale

2025 GMC Sierra 1500 For Sale
32,844 listings starting at $32,565
2024 GMC Sierra 1500 For Sale
198 Great Deals out of 18,391 listings starting at $25,310
2023 GMC Sierra 1500 For Sale
247 Great Deals out of 3,019 listings starting at $24,998
2022 GMC Sierra 1500 For Sale
145 Great Deals out of 1,829 listings starting at $24,607
2021 GMC Sierra 1500 For Sale
265 Great Deals out of 3,463 listings starting at $20,597

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. Content will be removed if CarGurus becomes aware that it violates our policies.