Does 8mm spark plug wires create misfire?
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Does 8mm spark plug wires create misfire?
I've recently replaced stock wires with the bigger taylor spyro pro 8mm.
Is not a big deal cause a bigger clip retainer would be required, anyway at the moment i'm running with the stock clips. (Wires are a little bit squeeze in them)
Anyway Strange thing is happening since when i've replaced wires and ive never noticed it before...
Only in 6th gear when climbing hill with full throttle and low rpm, appears misfire (i think it's misfire car looks like turn off engine for an half of a second for one two three times)
Wondering 8mm wires could be culprit? A bigger coil would be reccomended? Or that little squeeze could be culprit?
Still just the same day ive replaced wires, ive made a full tank of mid grade gas...it is 95 octane european gas that should be like your u.s 89 mid grade gas...usually i run with 100 octane that is like u.s. premium 91 and never had trouble...
Problem is that i've already re-filled tank with premium gas again (about half tank of premium) and problem still there's
Is not a big deal cause a bigger clip retainer would be required, anyway at the moment i'm running with the stock clips. (Wires are a little bit squeeze in them)
Anyway Strange thing is happening since when i've replaced wires and ive never noticed it before...
Only in 6th gear when climbing hill with full throttle and low rpm, appears misfire (i think it's misfire car looks like turn off engine for an half of a second for one two three times)
Wondering 8mm wires could be culprit? A bigger coil would be reccomended? Or that little squeeze could be culprit?
Still just the same day ive replaced wires, ive made a full tank of mid grade gas...it is 95 octane european gas that should be like your u.s 89 mid grade gas...usually i run with 100 octane that is like u.s. premium 91 and never had trouble...
Problem is that i've already re-filled tank with premium gas again (about half tank of premium) and problem still there's
Last edited by Christi@n; Jun 27, 2017 at 09:15 AM.
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
possible - I have on occasion, got a bad tank of gas, but not often. i'm thinking only once or maybe twice in my lifetime - in fact, I can only recall one time. bad gas - a slim chance, but not likely.
since the issue seems to be related to the wires, zero in on that. if you can and if they are still good, swap out the originals. inspect each 8mm wire for any kind of damage - especially around the retaining clips.
since the issue seems to be related to the wires, zero in on that. if you can and if they are still good, swap out the originals. inspect each 8mm wire for any kind of damage - especially around the retaining clips.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
8mm performance plug wires like the Taylor wires you installed are not the problem. If anything, the lower resistance in performance wires should provide more electrical energy to the plugs.
How fast were you going in that 6th gear, going uphill at full throttle? You said "low RPM" and it sounds like you were lugging the engine and that would certainly cause the noise you heard. Probably pinging if not some sort of detonation. Using a gas that is effectively not premium fuel won't help. You should stay with that 100 octane (91 US) gas.
6th gear in a ZF trans is a .5:1 ratio. 6th is really designed for steady cruising on places like freeways/autobahn/autostrade where the speed limits would be at least 100KM or above. Manual trans-equipped cars like the C4 (and the C5) typically reached their advertised top speed in 5th gear, not 6th.
How fast were you going in that 6th gear, going uphill at full throttle? You said "low RPM" and it sounds like you were lugging the engine and that would certainly cause the noise you heard. Probably pinging if not some sort of detonation. Using a gas that is effectively not premium fuel won't help. You should stay with that 100 octane (91 US) gas.
6th gear in a ZF trans is a .5:1 ratio. 6th is really designed for steady cruising on places like freeways/autobahn/autostrade where the speed limits would be at least 100KM or above. Manual trans-equipped cars like the C4 (and the C5) typically reached their advertised top speed in 5th gear, not 6th.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
8mm performance plug wires like the Taylor wires you installed are not the problem. If anything, the lower resistance in performance wires should provide more electrical energy to the plugs.
How fast were you going in that 6th gear, going uphill at full throttle? You said "low RPM" and it sounds like you were lugging the engine and that would certainly cause the noise you heard. Probably pinging if not some sort of detonation. Using a gas that is effectively not premium fuel won't help. You should stay with that 100 octane (91 US) gas.
6th gear in a ZF trans is a .5:1 ratio. 6th is really designed for steady cruising on places like freeways/autobahn/autostrade where the speed limits would be at least 100KM or above. Manual trans-equipped cars like the C4 (and the C5) typically reached their advertised top speed in 5th gear, not 6th.
How fast were you going in that 6th gear, going uphill at full throttle? You said "low RPM" and it sounds like you were lugging the engine and that would certainly cause the noise you heard. Probably pinging if not some sort of detonation. Using a gas that is effectively not premium fuel won't help. You should stay with that 100 octane (91 US) gas.
6th gear in a ZF trans is a .5:1 ratio. 6th is really designed for steady cruising on places like freeways/autobahn/autostrade where the speed limits would be at least 100KM or above. Manual trans-equipped cars like the C4 (and the C5) typically reached their advertised top speed in 5th gear, not 6th.
Also there was not any noise just a cut off of the engine power
Last edited by Christi@n; Jun 27, 2017 at 01:43 PM.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Recently replaced with ngk iridium...still good think...they have ran 10k miles. Eventually i would correct the gap
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Sep 2001
Posts: 62,161
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
No, highly unlikely any code set for this kind of problem.
I would check all wires and make sure none contact the pipes, make sure the firing order is correct (though that would almost definitely cause a backfire bang) on the wires. Might need to hook a scanner up and see what its reading when you get a miss.
I would check all wires and make sure none contact the pipes, make sure the firing order is correct (though that would almost definitely cause a backfire bang) on the wires. Might need to hook a scanner up and see what its reading when you get a miss.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
No, highly unlikely any code set for this kind of problem.
I would check all wires and make sure none contact the pipes, make sure the firing order is correct (though that would almost definitely cause a backfire bang) on the wires. Might need to hook a scanner up and see what its reading when you get a miss.
I would check all wires and make sure none contact the pipes, make sure the firing order is correct (though that would almost definitely cause a backfire bang) on the wires. Might need to hook a scanner up and see what its reading when you get a miss.
Do you think can this contact make a bad ground?
Aren't cables isolated?
Last edited by Christi@n; Jun 27, 2017 at 04:35 PM.
Team Owner
Joined: Sep 2001
Posts: 62,161
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
The wires are insulated yes, but if one has hit an exhaust pipe and burnt, even a little, it can cause this misfire. I've run into that many times, even when I thought none were in contact. Look at the boots too.
Touching another metal bracket should not cause it.
You may want to fire the engine in the dark and see if you see arcing.
Touching another metal bracket should not cause it.
You may want to fire the engine in the dark and see if you see arcing.
Drifting
Joined: Mar 2015
Posts: 1,275
Likes: 165
From: Utah
While i doubt it's your problem, msd for one makes these little wire separator clips.
the idea is to keep an air gap between the wires, making sure they are not touching each other.
Or atleast limit the touching to a miminimum.
Also one time i had a rotor screw work it's way loose on my S10.
It idled fine, but on the freeway i got some weird surging.
One night as it got worse i opened the hood, and there it was.
Arching coming from the distributor cap area.
For fun, take a good look in low light. Rev the engine etc and look for any light show...
the idea is to keep an air gap between the wires, making sure they are not touching each other.
Or atleast limit the touching to a miminimum.
Also one time i had a rotor screw work it's way loose on my S10.
It idled fine, but on the freeway i got some weird surging.
One night as it got worse i opened the hood, and there it was.
Arching coming from the distributor cap area.
For fun, take a good look in low light. Rev the engine etc and look for any light show...
Race Director
Joined: Sep 2001
Posts: 14,682
Likes: 753
From: NEwhere Ohio
its highway low rpm. the experience seems like something out of balance.
gapped them to .036" and no issues
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
It is just a little bit curios why do you use in America .035 and we use in Italy ,035...
Also it looks like you usually use comma in this case 1,200,000.00 $ Mmmmm
I would write it this way 1.200.000,00 €
Also it looks like you usually use comma in this case 1,200,000.00 $ Mmmmm
I would write it this way 1.200.000,00 €
Last edited by Christi@n; Jun 28, 2017 at 07:05 PM.
