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 Ross Your Own Question

Ross, Diagnostic and repair technician
Category: Car
Satisfied Customers: 1180
Experience:  Licensed diagnostic and repair technician
Type Your Car Question Here...
Ross is online now

My VW polo is misfiring at low revs and on idle. It is a 1999

Customer Question

My VW polo is misfiring at low revs and on idle. It is a 1999 1.4 CL 8v engine. Could this be an injector problem or associated with a HT lead other ignition system fault?
Submitted: 4 years ago.
Category: Car
Expert:  Ross replied 4 years ago.

techmachine :

Hi, welcome to Just answer! My name is Ross and i will help with your question

techmachine :

The next part to change would be the HT leads. I would recommend you change the leads and the distributor cap and rotor arm too as these often get forgotten about during services, I have had a few misfires in the past which were caused by the distributor cap and as all of these parts are service items, I would do these first.

I have had several Coolant temperature sensors cause this problem on these engines, There is a 4 pin plastic sensor that clips into the coolant flange on the right hand front of the engine, If you have access to a diagnostic scanner it may help identify this as a cause, but these fail regularly cost around £27

If the problem is still there I would advise you to fit some spark detectors that will show the spark while the engine is running, this will help identify whether its caused by lack of spark or an injection problem. If there are no problems with the ignition it could be related to a fuel injector. It would be wise at this point to carry out a compression test just to ensure all cylinders are of equal compression, If you smell un-burnt fuel in the exhaust its more likely to be a problem with ignition that an injection problem.

I hope this helps, please feel free to ask if you need further assistance, regards, Ross.

What Customers are Saying:

  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • 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

Meet The Experts:

  • Greg



    Satisfied Customers:

    Automotive diagnostic tech
< Previous | Next >
  • Greg's Avatar



    Satisfied Customers:

    Automotive diagnostic tech
  • Matt's Avatar


    Mechanical Engineer

    Satisfied Customers:

    BEng hons Mech engineering, in auto industry 22 years
  • Ross's Avatar


    Diagnostic and repair technician

    Satisfied Customers:

    Licensed diagnostic and repair technician
  • Rob's Avatar


    ASE Certified Technician

    Satisfied Customers:

    30 years trade experience
  • uk_iaibal's Avatar


    UK Car Mechanic

    Satisfied Customers:

    Verified Car Mechanic.
  • Billy's Avatar


    Trainer/ Master Technician

    Satisfied Customers:

    Trainer 8+ years, master tech. 10+ years, SAE member
  • Mike Kelly's Avatar

    Mike Kelly

    Auto Service Technician

    Satisfied Customers:

    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.