My hyundai V6 Auto yr2000 2.5 petrol runs fine for anywhere between 5 / 20 miles before suddenly suffering a major fluctuation in revs and almost cutting out. It carries on running but seems to be a cylinder short and sounding 'pop pop' just like running short of a pot but I have no power. Doesnt seem to be limp mode, when I put throttle on; it kicks down but will not rev past 2500 rpm so just goes back up to third gear I think. I have no lights on and have had the diagnostics read, there are no codes coming up, unfortunately even solas is unable to communicate with it. Can anyone help. Am on budget with a new baby on way, Simply cant afford hyundai prices at more than £100 an hour. We love the car and have spent hundred upon hundred keeping her up together, new rad, new brakes, tyres and servicing so dont want to let her go now. Thanks people. Any help appreciated!
Symptoms indicates misfiring and a possible fault with the ignition system. Have the coils tested to see if any are out of specs.
Ignition Coil Resistance (Sonata 2.5L)
Disconnect ignition coil 4-pin connector. Measure primary coil resistance for cylinders No. 1 and 4 between connector terminals No. 2 and 3. Measure primary coil resistance for cylinders No. 2 and 5 between connector terminals No. 1 and 3. Measure primary coil resistance for cylinders No. 3 and 6 between coil connector terminals No. 3 and 4. See Fig. 9. Replace coil if resistance is not as specified.
2. To check secondary coil resistance, disconnect spark plug wires. Measure resistance between high-voltage coil terminals No. 1 and 4, between terminals No. 2 and 5, and between terminals No. 3 and 6. See
Fig. 9. Replace coil if resistance is not as specified.
DIS IGNITION COIL RESISTANCE - Ohms @ 68 F (20 C)
Primary coil resistance = 0.67-0.8111, Ohms @ 68 F (20 C)
Secondary coil resistance = 305-15,295 Ohms, @ 68 F (20 C)
Resistance value is with coil power transistor energized using a 3-volt power supply and ground connected to terminals No. 1 and 2.