Rough idle

Asked by Mar 27, 2016 at 10:35 PM about the 1991 GMC Sierra 1500 C1500 SLE Extended Cab LB

Question type: Maintenance & Repair

Rough idle won't stay running have change
elec.spark control, idle air control,plugs,map
sensor,tps, and the ecm.. Still running rough but if
you unscrew the IAC it idles high but the miss
smooths out...I am at a loss any ideas

12 Answers

10

My car is a 2005 chevy aveo it. Stalls out when take off oil light blinks off and on what could the problom

210

Almost sounds like it's missing. Have you changed the spark plug wires? I would pulling by one answer if you notice a difference. Could have a bad wire. Sounds like a timing issue.

10

Yup. It chugs a chugen

10

Does it cost alot to fix

210

New cap and rotor?

210

Pull your cap if you not changed it. Check inside it. See if you see white lines on the inside. Best describes and white lightning marks. Could be bad cap that's causing a misfire.

10

I bought the car off rightway. 5 months ago still maken payments

210

Sorry I was answering the questions. Above for this forum. But have you checked to make sure you have oil?

210

My rule of thumb is always check fluids and change oil when buying a used Alvarez that is not certified.

10

Ok i will do i just checked it and added a qt of oil

10

What cap and where is it located

92,865

Better do a compression check you could have a dead or very weak cylinder.

Your Answer

Add photo

Related Questions

  • rough idling 3 answers

    why does my 98 Sierra idle rough between 1st and 2nd gear,? it's 2wd runs good once it gets out of 2nd,gears switch right on with the rpms at 2,500. what could our be.?

    1998 GMC Sierra 1500 C1500 SL Extended Cab SB

    -

    Maintenance & Repair

  • Rough idle and bubbling noise under cab 2 answers

    I have a 91 GMC Sierra 1500 5.0 . It idles rough at low speed sometimes stalling . Runs fine at a higher speed . There's also a bubbling noise under the cab like it's coming from the muffler...

    1991 GMC Sierra 1500 C1500 SLE Extended Cab LB

    -

    Maintenance & Repair

  • Why does it rough idling on startup? 2 answers

    Weather its cold or warm on startup it idles rough then rpm goes up to 1500 and smoothes out and runs great, idles good after that.

    1995 GMC Sierra 1500 C1500 SLE Extended Cab Stepside SB

    -

    Maintenance & Repair

  • Idling very rough after a tune up, heck engine light came on. 1 answer

    2012 GMC Sierra 1500 SLT Ext. Cab 4WD

    -

    Maintenance & Repair

  • idle rough 3 answers

    my truck is idling really rough it dosent seem bad when im driving but when i come to a stop it shakes really bad , or when i first start it , what can it be ??

    1998 GMC Sierra 2500 2 Dr K2500 SLE 4WD Extended Cab LB HD

    -

    Maintenance & Repair

Sierra 1500

Looking for a Used Sierra 1500 in your area?

CarGurus has 68,200 nationwide Sierra 1500 listings starting at $2,484.

ZIP:

Search GMC Sierra 1500 Questions

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 5,010
#2 John Saffrahn
John Saffrahn
Reputation 3,540
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 3,150
View All

Related Models For Sale

Used Ford F-150
2,194 Great Deals out of 206,316 listings starting at $1,499
Used GMC Yukon
376 Great Deals out of 18,226 listings starting at $2,950
Used Chevrolet Camaro
225 Great Deals out of 30,943 listings starting at $1,217

Used Cars For Sale

2017 GMC Sierra 1500 For Sale
43 Great Deals out of 44,111 listings starting at $20,121
2016 GMC Sierra 1500 For Sale
78 Great Deals out of 3,645 listings starting at $17,888
2015 GMC Sierra 1500 For Sale
102 Great Deals out of 3,926 listings starting at $15,400
2014 GMC Sierra 1500 For Sale
118 Great Deals out of 4,152 listings starting at $14,495
2013 GMC Sierra 1500 For Sale
66 Great Deals out of 2,009 listings starting at $9,600

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.