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Kevin, Auto Mechanic
Category: Hyundai
Satisfied Customers: 2018
Experience:  Diagnostic technician
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Hyundai Sonata GL: just replaced the valve cover gaskets on

Customer Question

just replaced the valve cover gaskets on 2002 Hyandai Sonata. Re-clamped the contections and vac hoses. Car starts, backfires, and doesn't idle. When excelerating, engine runs smooth. Was running fine prior.  Will accelerate, but weak, and dies.  Puts out unburned fuel out the exhaust.  I believe that I put back all of the connections and hoses properly.

Submitted: 2 years ago.
Category: Hyundai
Expert:  Kevin replied 2 years ago.
Hi I'm Kevin I don't have info on this model but il try and help .firstly I'm assuming car is petrol. Does engine have plug leads or coils as it sounds like plug leads are in wrong order
Customer: replied 2 years ago.

I had done the valve cover on the forward 3 and ran the car. All smooth. Did the same with the rear 3 under the intake (marked each as came out, but will go back tonight after work and remove the intake and recheck. It has the plug leads that go through the valve cover. Believe that they are correct. Could it be the three wires that plug in (one lined up with each plug. Smaller with snap on?

Expert:  Kevin replied 2 years ago.
The popping back noise suggests that a timing issue is occurring so unless you have unplugged anything else it's likely a plug lead on the wrong plug
Customer: replied 2 years ago.

will try it. Thanks.

Expert:  Kevin replied 2 years ago.
No worries let me know how you get on
Expert:  Kevin replied 2 years ago.
How did you get on