Misifre - Mustang Evolution

Go Back   Mustang Evolution > 4 Cylinder | V6 | Classic Mustangs || Tech and Talk > Pre-2005 V6 Mustang



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 01-24-2018, 09:19 AM   #1
Registered User
Newbie
 
Join Date: Dec 2017
Location: Chicago
Region: Illinois
Posts: 5
Misifre

I have a 2000 3.8 and I have had no problems with it up until now. A couple weeks ago it started shaking kinda bad and I thought it was the driveshaft but I inspected it and everything is fine and I had my teacher check it out (Automotive Technology school). After connecting the scan tool to it, turns out I had a misfire in cylinders 1 and 5 due to bad ignition coil so I replaced the ignition coil with an OEM Motorcraft one, fired it up and still having the same issue but according to the scan tool we fixed the misfire. We checked plugs and wires and everything is fine but still misfires pretty bad, and we did a Motor Vac on it to make sure all the injectors and everything inside is clean. Any idea on what can be causing this issue?
el_chapulin is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-24-2018, 10:35 AM   #2
Registered Member
Regular
 
Voltwings's Avatar
 
Join Date: May 2014
Location: Houston
Region: Texas
Posts: 3,639
How many miles? My 01 had factory ignition coil and spark plug wires at 85k, and when i replaced them i could literally hear the difference in the exhaust at idle it was running so much smoother / hitting so much harder.

If you have enough miles, the ignition coil is only part of the equation, go ahead and replace the wires and plugs as well.
Voltwings is offline   Reply With Quote
Old 01-24-2018, 10:38 AM   #3
Registered User
Newbie
 
Join Date: Dec 2017
Location: Chicago
Region: Illinois
Posts: 5
Quote:
Originally Posted by Voltwings View Post
How many miles? My 01 had factory ignition coil and spark plug wires at 85k, and when i replaced them i could literally hear the difference in the exhaust at idle it was running so much smoother / hitting so much harder.

If you have enough miles, the ignition coil is only part of the equation, go ahead and replace the wires and plugs as well.
I'm at a little under 149,000 miles and I replaced plugs about a month or two ago but I did not replace cables, when my teacher inspected them he said that they were still in good conditions.
el_chapulin is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-24-2018, 10:51 AM   #4
Registered Member
Regular
 
Voltwings's Avatar
 
Join Date: May 2014
Location: Houston
Region: Texas
Posts: 3,639
Unless he measured the resistance across them, he really didn't, a visual inspection wont cut it on something like this. They're cheap enough, replace them anyways.
Voltwings is offline   Reply With Quote
Old 01-24-2018, 10:58 AM   #5
Registered User
Newbie
 
Join Date: Dec 2017
Location: Chicago
Region: Illinois
Posts: 5
Quote:
Originally Posted by Voltwings View Post
Unless he measured the resistance across them, he really didn't, a visual inspection wont cut it on something like this. They're cheap enough, replace them anyways.
Ohhh okay I see, I might have to replace them then but what I find really weird is that the scan tool is reading no misfire and it's one of the good snap-on scan tools so I'm sure it's reading correct
el_chapulin is offline   Reply With Quote
Old 01-24-2018, 11:27 AM   #6
Registered Member
Regular
 
Voltwings's Avatar
 
Join Date: May 2014
Location: Houston
Region: Texas
Posts: 3,639
Not every code / fault scans constantly. Some only cycle / scan every 50 - 100 miles. So you may have done one particular piece of driving that triggered the initial fault code, and while the car may still be driving poorly, the same conditions may not have been met to trigger the fault code again.

What you can also do is move the wires around. You said the fault was on 1 and 5? Swap the wires with 2 and 6 for example, go drive it hard and see if fault codes for 2 and 6 come up (basically seeing if the issue follows the wires). I'm not sure how accurate those old computers are, but that's one thing to try without spending money.
Voltwings is offline   Reply With Quote
Old 01-24-2018, 11:31 AM   #7
Registered User
Newbie
 
Join Date: Dec 2017
Location: Chicago
Region: Illinois
Posts: 5
Quote:
Originally Posted by Voltwings View Post
Not every code / fault scans constantly. Some only cycle / scan every 50 - 100 miles. So you may have done one particular piece of driving that triggered the initial fault code, and while the car may still be driving poorly, the same conditions may not have been met to trigger the fault code again.

What you can also do is move the wires around. You said the fault was on 1 and 5? Swap the wires with 2 and 6 for example, go drive it hard and see if fault codes for 2 and 6 come up (basically seeing if the issue follows the wires). I'm not sure how accurate those old computers are, but that's one thing to try without spending money.
I think I'm just going to throw some new wires on there either way, it can't make it worse especially at almost 150,000 miles and looks like stock wires too
el_chapulin is offline   Reply With Quote
Old 01-24-2018, 11:42 AM   #8
Registered Member
Regular
 
Voltwings's Avatar
 
Join Date: May 2014
Location: Houston
Region: Texas
Posts: 3,639
that is 100% the right attitude to have haha.
Voltwings is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > 4 Cylinder | V6 | Classic Mustangs || Tech and Talk > Pre-2005 V6 Mustang

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


» Like Us On Facebook



01:37 AM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.