How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask fix that car Your Own Question

fix that car
fix that car, GMC Mechanic
Category: GM
Satisfied Customers: 493
Experience:  working on all makes of GMC cars and trucks for over 15 years
14855034
Type Your GM Question Here...
fix that car is online now
A new question is answered every 9 seconds

1990 5.7 liter gmc truck. Just tuned up. Engine is running rough.

Resolved Question:

1990 5.7 liter gmc truck. Just tuned up. Engine is running rough. Sooty deposits on plugs.
Submitted: 5 years ago.
Category: GM
Customer: replied 5 years ago.
Did not have the problem until after the tune up. Never got it to run right. No check engine light. Pulled plug and arced to block. Arc was yellow and not blue.
Expert:  fix that car replied 5 years ago.

ok it sounds like the plug wires are not on correctly, here is a diagram showing how they should be. hope this helps.

graphic

Customer: replied 5 years ago.
Wish that that was it.
Expert:  fix that car replied 5 years ago.
ok well if the problem was not there untill after the tune up then one of the componets must be faulty. does it feel like the engine is missing? if you remove one plug wire at a time is there a cylinder that with the plug wire disconnected the engine runs the same?
Customer: replied 5 years ago.
All of the cylinders are sooty. I can move the distributor almosr 90 degrees with no change in performance. Already changed cap again as it was causing intermittent misfires.
Expert:  fix that car replied 5 years ago.
ok this makes no sense. no problem before tune up, after tune up you can move the distributer 90 degrees? with no change? did you remove the dist. during the tune up?
Customer: replied 5 years ago.
Distributor was pulled. Bottom end on engine redone. Heads were not pulled. New timing chain.
Expert:  fix that car replied 5 years ago.
ah ha the plot thickins:) ok the timing is definetly off we need to bring the engine to top dead center (TDC) and make sure the distributer is set so the rotor is pointing towards #1 on the cap. if you want to play with it you can move all the wires over one spot on the cap and retest it should get better. maybe two spots depending on how retarded the timing is. did you set the timing chain? if so are you sure the marks were lined up. sorry I mean no offense to your skills just trying to cover the bases.
Customer: replied 5 years ago.
Triple checked tdc. Timing marks lined up just fine. I know why you are asking these things. I've torn into quite a few sbc engines and never had problems like this.
Expert:  fix that car replied 5 years ago.
have you checked for a plugged exaust sys.?
Customer: replied 5 years ago.
yes
Expert:  fix that car replied 5 years ago.
i'm still here. I have some info for you to check for the sooty plug conditon. hope this helps. I am turning in for the night its almost midnight here I have to be up at 4 am. if you would like I will repost this for you or we can pick it up in the morn. your choice.:)graphic
fix that car, GMC Mechanic
Category: GM
Satisfied Customers: 493
Experience: working on all makes of GMC cars and trucks for over 15 years
fix that car and 6 other GM Specialists are ready to help you
Expert:  fix that car replied 5 years ago.
hey bud, any news?

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Gary

    GMC Technician

    Satisfied Customers:

    903
    15 years gm master tech/15 years ASE master tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    GMC Technician

    Satisfied Customers:

    903
    15 years gm master tech/15 years ASE master tech
  • http://ww2.justanswer.com/uploads/CA/caprio23/2011-12-13_155550_20111213105344.64x64.jpg Anthony's Avatar

    Anthony

    ASE Certified Technician

    Satisfied Customers:

    476
    ASE Master Automobile Technician with over 20 years exp.
  • http://ww2.justanswer.com/uploads/Rocket2005/2009-09-13_133703_jack.jpg car tech's Avatar

    car tech

    ASE Certified Technician

    Satisfied Customers:

    448
    25 year master tech and shop owner
  • http://ww2.justanswer.com/uploads/2P/2paulm/2012-4-4_183431_justabswer.64x64.jpg Paul M ASE Master's Avatar

    Paul M ASE Master

    ASE Master Tech

    Satisfied Customers:

    187
    ASE Master Tech 20+ Years
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka- Moose)'s Avatar

    Chris (aka- Moose)

    GMC Technician

    Satisfied Customers:

    89
    16 years of experience
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    GMC Technician

    Satisfied Customers:

    360
    ASE Master Technician advanced level specialist
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    GMC Technician

    Satisfied Customers:

    2262
    ASE Master Certification. GM World Class Certification