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Misfire caused by Alternator?

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And_44

10+ Year Contributor
835
8
Feb 13, 2010
Marysville, Washington
Hey there,

So after replacing many parts with other to diagnose a misfire in all rpm ranges I have a question.

The ignition coil/module receive there voltage directly from alternator.

My problem.... I get spark to all four ports on my coil, BUT with the wires attached I'm not getting enough charge through the wire that is furthest away on the coil from the +/- posts on the back to trigger my timing light, I can switch my wires on the posts and the no signal follows the one post on the coil and not the wires. I've swapped my ignition module with 2, and my coil with 3. All same results. The

So my question could the alternator when warm/hot be putting out a lower voltage to not put enough of a spark on the posts furthest away from the +/- on the back of coil?
 
Was the alternator. Replaced it with a new one and works wonders. Wires, plugs are brand new. I've swapped 3 known good coils and 2 modules and had same issue. I swapped the CAS, throttle body with new seals and good TPS/ISC, and ECU and same issue.

When I swapped the CAS and had to adjust the timing I realized the coil wasn't getting enough power to send a signal down the 1 wire, but was getting a signal in the 4 wire, when I removed the offset wire I was getting a spark but was pretty weak. How the coil is set up with the power supply directly behind the one post and the other being offset when what power was getting to coil to ignite the plugs it was taking the shortest route possible and what was left was going to the offset wire. I flipped the wires and the problem followed the posts on the coil so ruled out my wires. But this was the 3rd coil I had in there and couldn't of been the coil(s). The ignition module was the 2nd one installed and couldn't of been that.

I tried looking for something in ignition to regulate the power but could only find that the Alternator had an internal regulator. When I thought back to when problem started (ie I replaced exhaust manifold, new PCV, started using cheap ARCO/AMPM gas) it was easy because those where the most noticable differences in what I did with car and only changes made. But I remembered that when I replaced the manifold my water inlet pipe o-ring leaked a good amount of coolant and when that leaks it leaks onto your Alternator.

This hit me like a ton of bricks. The Alternator is a mass of coils that when cool are fine, but when heated they expands and can cause lose of contacts/charge, and it quickly cools when car is not running, then quickly reheats.
 
Was the alternator. Replaced it with a new one and works wonders. Wires, plugs are brand new. I've swapped 3 known good coils and 2 modules and had same issue. I swapped the CAS, throttle body with new seals and good TPS/ISC, and ECU and same issue.

When I swapped the CAS and had to adjust the timing I realized the coil wasn't getting enough power to send a signal down the 1 wire, but was getting a signal in the 4 wire, when I removed the offset wire I was getting a spark but was pretty weak. How the coil is set up with the power supply directly behind the one post and the other being offset when what power was getting to coil to ignite the plugs it was taking the shortest route possible and what was left was going to the offset wire. I flipped the wires and the problem followed the posts on the coil so ruled out my wires. But this was the 3rd coil I had in there and couldn't of been the coil(s). The ignition module was the 2nd one installed and couldn't of been that.

I tried looking for something in ignition to regulate the power but could only find that the Alternator had an internal regulator. When I thought back to when problem started (ie I replaced exhaust manifold, new PCV, started using cheap ARCO/AMPM gas) it was easy because those where the most noticable differences in what I did with car and only changes made. But I remembered that when I replaced the manifold my water inlet pipe o-ring leaked a good amount of coolant and when that leaks it leaks onto your Alternator.

This hit me like a ton of bricks. The Alternator is a mass of coils that when cool are fine, but when heated they expands and can cause lose of contacts/charge, and it quickly cools when car is not running, then quickly reheats.


I'm having the same issue with mine I thought it wasn't the alternator but looks like it is
 
yea I'm going to test it today this happen to me last night but I'm pretty sure it's the alternator.... the battery is drained and when I cable jump it , it doesn't last to long while it's on and when I accelerate that's when the misfire begins and stutters
ORIGINAL ALTERNATOR -1990
 
Go with a 96 Galant alternator. Has more amps, is plug and play and bolts up directly.
 
I have an O'rielly's unit, lifetime warranty. Works great. That's what this forum is all about, sharing idea's, some good, some not so good, but a lot of good people on here.
 
Alright guys so I have another problem hopefully I could get a better answer. recently I replace my clutch+flywheel+clutch fork+throw out bearing+slave cylinder.. etc
So the problem is that I'm hearing a rattling in the transmission when I accelerate it (car is in no motion) kinda sounds like I'm running diesel but goes away when it goes back to idle or when I engage the clutch.

Some people told me it's normal??? :confused:
 
Hello everyone so the problem was irrelevant... seems like it was just some clutch chatter and I just I had break the clutch in.

:ohdamn: I should of known better but better safe then sorry LOL

thanks for all your help guys !
 
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