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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?
 

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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.
 

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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.
 

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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.
 

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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
 

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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.
 

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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
 
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