What do plugs/wires look like of the car is misfiring?


#1

I think my 2006 Hyundai Elantra is misfiring. When I’m slowing and then accelerating again on a cloverleave off/on ramp, at the top of the ramp, there’s about a two second delay in power as I try to get back up to speed. I press the accelerator and the RPM needle does not move - it hovers around 1500 RPMs - and then will suddenly shoot up to 2500-3000. When the accelerator is pressed, the car car does not increase speed until something kicks in.



The check engine light is not on, the dealer ran diagnostics and nothings shows up, the dealer says that it’s common for this car to have a short delay between the shifting in this situation, and that basically it’s my driving of a newer car causing the problem (older cars have a different type of fuel system and I’m not used to the new system). They have not been able to replicate the problem, although it occured as I was driving when the service manager was in the car.



So…I want to check the plugs and wires myself, but don’t know what to look for.



If you have any other ideas of what could be causing this, besides that mentioned above, feel free to offer opinions.



Thanks!


#2

I doubt if you have enough miles on that 2006 to need new plugs or wires. Most of the time when there is some sort of wire-plug failure you will get a CEL. BTW sometimes the CEL does not light or you miss it and there is a code stored. You may want to check and see.

I suspect a fuel or transmission issue.


#3

You don’t have a missfire. I believe your car is a drive by wire setup. Instead of a linkage between the pedal and the throttle, you now have a pedal that sends its position to the computer which inturns sends it’s signal to small motor on the throttle that opens or closes the throttle plates. There have been complaints on many cars with this setup of a small delay.


#4

Do you have an automatic transmission?

If so, the jump in RPM and the kick may be just the transmission downshifting in response to your pressing down on the accelerator pedal.


#5

1.) Has your car always done this?

2.) Can you drive an identical car belonging to someone else and duplicate the problem?

3.) An electrical “miss” can often be intentionally induced by holding the transmission in 2nd or 3rd gear and accelerating gradually under load. At some repeatable, specific RPM you’ll feel it in your hands.

I agree with Joseph that it sounds more like a transmission that downshifts too late, or a fuel delivery problem.


#6

What’s going on is that your vehicle is downshifting. To make shifts smoother, most new vehicles retard the timing until the shift is complete, therefore, no power until the transmission engages the new gear.

As to your question, in newer vehicles, misfiring plugs and wires look just like plugs and wires that are working. Chances are that there is nothing wrong with them.