Slight delay, missfire ? How to check
Thread Starter
Pro
Joined: Dec 2017
Posts: 687
Likes: 102
From: Albany NY
Slight delay, missfire ? How to check
2017 Grand Sport CE Auto. Almost 50,000 miles, my daily work car.
I've noticed when cruising at 70-75 AND do a slight peddle push, a slow delay/missfire, SOMETIMES, a plug? plug wire?
Gas line is always clean with Techtron added every 3rd tank full and 93 Octane, I have a plug in, what you call it, to keep mine in V8 all the time.
Change out plugs?
Change out plug wires?
Then replace a elect. pack, (Cost ????)
How would you troubleshoot?
I've noticed when cruising at 70-75 AND do a slight peddle push, a slow delay/missfire, SOMETIMES, a plug? plug wire?
Gas line is always clean with Techtron added every 3rd tank full and 93 Octane, I have a plug in, what you call it, to keep mine in V8 all the time.
Change out plugs?
Change out plug wires?
Then replace a elect. pack, (Cost ????)
How would you troubleshoot?
Instructor
Joined: Oct 2019
Posts: 111
Likes: 44
From: Denver, CO.
Here's a couple of thoughts---
1. My Range device glitched on my A6 one time. I checked the DIC display and it showed that the V4 - V8 mode was activating and I also heard an AFM valve mechanical 'squeak' or 'tweet' when it changed modes. I unplugged and replugged the device and that anomaly stopped immediately. I sent it to the mfgr. who is now in Utah and they said the software was corrupt. and reflashed it for free since I bought it directly from them.
2. Select the DIC screen that shows the V4 or V8 readout and watch it as you drive in Automatic mode. Is there a correlation to your hesitation?
3. Drive in Manual mode and the V4 mode will be disabled. Still have the hesitation?
1. My Range device glitched on my A6 one time. I checked the DIC display and it showed that the V4 - V8 mode was activating and I also heard an AFM valve mechanical 'squeak' or 'tweet' when it changed modes. I unplugged and replugged the device and that anomaly stopped immediately. I sent it to the mfgr. who is now in Utah and they said the software was corrupt. and reflashed it for free since I bought it directly from them.
2. Select the DIC screen that shows the V4 or V8 readout and watch it as you drive in Automatic mode. Is there a correlation to your hesitation?
3. Drive in Manual mode and the V4 mode will be disabled. Still have the hesitation?
Thread Starter
Pro
Joined: Dec 2017
Posts: 687
Likes: 102
From: Albany NY
No MOD'S, and I don't have a scanner. I'll try the suggested fixes. I'd love to have a Code Reader, have been waiting to when my "Drive Train" factory warrenty is over, and then will really need to step up to the plate. $$$$ any suggested Models.
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Thread Starter
Pro
Joined: Dec 2017
Posts: 687
Likes: 102
From: Albany NY
How about bad GAS. My kid borrowed my car for a day to show off to his GF, Neighbors & Co-workers. It was on 1/2 tank, 159 miles later it was on 1/2 a tank. He said he filled it back to when he got it......Could he have put in 87 Octane in. ???????? and if, will prob go away with new 93 O gas??
Instructor
Joined: Jul 2020
Posts: 243
Likes: 87
From: Raleigh, NC
If it got bad gas, drive it without getting into the pedal at all until near empty. A full tank of of premium will clear it up if that is the case. It is still recommended to get the codes read. Take it to one of the parts shops, they can scan it since you don’t have one. You could also download the torque app and get a Bluetooth ELM327 for $20 to do basic scan. They can detect misfires. If it misfires enough on hard acceleration, you should be seeing the check engine light start to flash.
Thread Starter
Pro
Joined: Dec 2017
Posts: 687
Likes: 102
From: Albany NY
Thank you much, you know your stuff. I did drive at 75-80MPH on a 2 hour highway trip with whatever amount my kid put in, so he drove 159 miles, it couldn't be a lot of 87OCT gas he topped it off with.