Misfires

JSur · 11-12-2018, 08:58 AM

Has anyone ever experienced power draw that drains the battery within days and fuel cut/misfiring from a bad starter and alternator? The car has been acting up pretty bad recently and my starter just fried. In the process of figuring that out we discovered my alternator is on the way out the door as well. Any accessory, when my voltage got low enough, would trigger a misfire or lean out on me. It even got bad enough at one point to where the blinker and auto window up/down would trigger a misfire or fuel cut. I’m currently going through the car and all it’s fuses etc but I would like to hear your thoughts and opinions on whether a bad alternator and starter could be the root cause of this power draw that’s been haunting me. Thanks

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dts3 · 11-12-2018, 09:47 AM

What is making you call it a low voltage condition? If your alternator is on it's way out, I'm curious if maybe it actually caused a voltage spike that blew your starter motor. If this is what happened, anything that's got a 12v line is in theory fair game. In the lab, we've ESD'd circuit boards that have failed in such a way that makes it hard to figure out what has happened. They would half-way work, but do all kinds of crazy ****. We had one case where a voltage spike killed a capacitor on a circuit board, but it failed closed (causing a short). This in turn caused it to destroy any other electronic hardware that it was plugged in to... almost like a hardware (as opposed to software) computer virus. I mention all of this to point out that transient voltage spikes can ruin things in very unexpected ways. Hopefully it can be diagnosed without spending money replacing many things.

JSur · 11-12-2018, 10:00 AM

Quote:

Originally Posted by dts3

What is making you call it a low voltage condition? If your alternator is on it's way out, I'm curious if maybe it actually caused a voltage spike that blew your starter motor. If this is what happened, anything that's got a 12v line is in theory fair game. In the lab, we've ESD'd circuit boards that have failed in such a way that makes it hard to figure out what has happened. They would half-way work, but do all kinds of crazy ****. We had one case where a voltage spike killed a capacitor on a circuit board, but it failed closed (causing a short). This in turn caused it to destroy any other electronic hardware that it was plugged in to... almost like a hardware (as opposed to software) computer virus. I mention all of this to point out that transient voltage spikes can ruin things in very unexpected ways. Hopefully it can be diagnosed without spending money replacing many things.

I don’t think it’s all tied to low voltage but the symptoms significantly decreased when I threw in a new battery. I believe the low voltage is just a product of the starter and/or alternator slowly going bad over time. The cars creeping up on 90k, has been boosted for over 30k, as well as a bunch of accessories that require lots of power. I’ve been told that a bad starter solenoid can cause a power draw. I’m hoping that by replacing those two parts it’ll, ideally, solve the power draw mystery, or at least bring me back up to par so I can properly track down the issue.

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mults · 11-12-2018, 10:36 AM

I am curious about your term "the starter fried". Did it smoke and need to be replaced, or have other symptoms?

As-far-as low voltage, it can be many things...Are any of the wires close to the hot components of your TT setup that could have melted? How low does the voltage get when you say "low voltage"? Is the voltage measured at the battery, or are you going from the voltmeter?

Electrical issues are undoubtedly the hardest to track down. Keep us posted as to any other symptoms or fixes...

JSur · 11-12-2018, 10:56 AM

Quote:

Originally Posted by mults

I am curious about your term "the starter fried". Did it smoke and need to be replaced, or have other symptoms?

As-far-as low voltage, it can be many things...Are any of the wires close to the hot components of your TT setup that could have melted? How low does the voltage get when you say "low voltage"? Is the voltage measured at the battery, or are you going from the voltmeter?

Electrical issues are undoubtedly the hardest to track down. Keep us posted as to any other symptoms or fixes...

The starter smoked, we did manage to get the car started after rocking it back and forth, but it is getting replaced. I’ll be ordering the starter and alternator this week.

The AAM Kit is super tight so there’s definitely a few things close. I haven’t dug that deep into yet. The only wire I can think of off the top of my head that run close are the 02 sensor wires and my AFR. I ceramic coated my down pipes and zip tied the wires as far away as I could without pulling too hard. I used a meter. The voltages measured 12.47 when it was off and around 13.1, give or take, while running. Which may not be an issue for regular cars but as I mentioned to the first guy I have A LOT of accessories that draw power. I have air compressors, head unit, amp, capacitor and a remote start system (left over from the previous owner which I’d like to rip out but can’t find it).

I’m really hoping that it’s not a melted wire or a short. Electrical issues are without a doubt the worst lol. I appreciate the input I will definitely update as I go along.

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SouthArk370Z · 11-12-2018, 11:18 AM

The starter shouldn't be the problem. Alternator - maybe; but it sounds like it's charging the battery, so it's low on my list at this point. Since the battery is discharging, I suspect an intermittent short; possibly related to the turbo install. Check system voltage with a meter. A recording meter will help spot intermittent problems.

Edit: Didn't fully read previous post. You have low voltage, so the alternator jumps to the top of my list.

bunk · 11-12-2018, 12:01 PM

FWIW, on my gf's focus, the engine would rev close to stalling when idling and you turn on the AC. Couldnt figure it out til the starter gave out, and found a frayed battery cable.

JSur · 11-12-2018, 01:35 PM

Quote:

Originally Posted by SouthArk370Z

The starter shouldn't be the problem. Alternator - maybe; but it sounds like it's charging the battery, so it's low on my list at this point. Since the battery is discharging, I suspect an intermittent short; possibly related to the turbo install. Check system voltage with a meter. A recording meter will help spot intermittent problems.

Edit: Didn't fully read previous post. You have low voltage, so the alternator jumps to the top of my list.

Yea the alternator is barely charging the battery. It’s really only charging enough to keep the thing alive. Along with a new starter I’m replacing the alternator. If those solve my issues I’ll be super excited lol. If not, I’m just gonna have to do some more digging.

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JSur · 11-12-2018, 01:37 PM

Quote:

Originally Posted by bunk

FWIW, on my gf's focus, the engine would rev close to stalling when idling and you turn on the AC. Couldnt figure it out til the starter gave out, and found a frayed battery cable.

This power draw has been haunting me for a really long time. But inly recently has it been bad enough to cause all the misfiring, leaning out etc issues. Before the starter went out I was just telling a friend of mine that whatever’s wrong with the car, I wish it would just break. Idc if its a little more money to replace if it’s broken but at least I know wtf was going on. It was driving me insane. And 3 days later the starter fried and here we are lol.

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bunk · 11-12-2018, 01:49 PM

Yeah, if your TT setup makes things a little tight in the engine bay, Id check the battery cables for frays or any oil/fluid leaks that may have sprayed into your starter or alternator.

dts3 · 11-12-2018, 02:36 PM

Quote:

Originally Posted by JSur

... I’m really hoping that it’s not a melted wire or a short. Electrical issues are without a doubt the worst lol. I appreciate the input I will definitely update as I go along.

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You should want the problem to be that simple lol. It'd be awesome to crawl under the car and visually see a few melted wires that can be easily replaced in five minutes.

JSur · 11-12-2018, 02:41 PM

Quote:

Originally Posted by dts3

You should want the problem to be that simple lol. It'd be awesome to crawl under the car and visually see a few melted wires that can be easily replaced in five minutes.

If I can visually see the wire then yea that would be the ideal situation lol. I was talking about if I have to track it down and run through the whole thing. That would suck lol

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dts3 · 11-12-2018, 04:07 PM

Quote:

Originally Posted by JSur

If I can visually see the wire then yea that would be the ideal situation lol. I was talking about if I have to track it down and run through the whole thing. That would suck lol

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Yeah lol, I was only thinking about it from the positive outcome

Ghostvette · 11-12-2018, 04:22 PM

Quote:

Originally Posted by JSur

Has anyone ever experienced power draw that drains the battery within days and fuel cut/misfiring from a bad starter and alternator? The car has been acting up pretty bad recently and my starter just fried. In the process of figuring that out we discovered my alternator is on the way out the door as well. Any accessory, when my voltage got low enough, would trigger a misfire or lean out on me. It even got bad enough at one point to where the blinker and auto window up/down would trigger a misfire or fuel cut. I’m currently going through the car and all it’s fuses etc but I would like to hear your thoughts and opinions on whether a bad alternator and starter could be the root cause of this power draw that’s been haunting me. Thanks

Sent from my iPhone using Tapatalk

If issues decreased with a new battery, then there are several things to consider. Reading through the posts, it appears you are replacing the alternator, that's good. Based on the numbers you posted, 13.1 VDC is barely enough to keep the battery charged, much less run everything else. A good alternator puts out between 13.5 & 14.5 VDC. Check all your grounds, make sure they are all clean and secure. A bad ground will raise havoc in any electrical system. If you are running an amplifier and not running a 1 to 2 farad capacitor, you are killing your alternator. Just some thoughts... good luck.

JSur · 11-13-2018, 07:32 AM

Quote:

Originally Posted by Ghostvette

If issues decreased with a new battery, then there are several things to consider. Reading through the posts, it appears you are replacing the alternator, that's good. Based on the numbers you posted, 13.1 VDC is barely enough to keep the battery charged, much less run everything else. A good alternator puts out between 13.5 & 14.5 VDC. Check all your grounds, make sure they are all clean and secure. A bad ground will raise havoc in any electrical system. If you are running an amplifier and not running a 1 to 2 farad capacitor, you are killing your alternator. Just some thoughts... good luck.

I do have a capacitor for the sub/amp. I actually re-grounded them both straight to the frame a while back. They were originally installed with the ground from the amp going to the capacitor ground, then into the frame, so I gave them both a direct ground and that didn’t fix anything. If my battery still drains after replacing alternator and starter then I have to dive into all the grounds. Thanks for the input

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11-12-2018, 08:58 AM	#1 (permalink)
JSur Base Member Join Date: Mar 2016 Location: Orlando Posts: 84 Drives: 2011 370z TT Rep Power: 9	Misfires Has anyone ever experienced power draw that drains the battery within days and fuel cut/misfiring from a bad starter and alternator? The car has been acting up pretty bad recently and my starter just fried. In the process of figuring that out we discovered my alternator is on the way out the door as well. Any accessory, when my voltage got low enough, would trigger a misfire or lean out on me. It even got bad enough at one point to where the blinker and auto window up/down would trigger a misfire or fuel cut. I’m currently going through the car and all it’s fuses etc but I would like to hear your thoughts and opinions on whether a bad alternator and starter could be the root cause of this power draw that’s been haunting me. Thanks Sent from my iPhone using Tapatalk

11-12-2018, 09:47 AM	#2 (permalink)
dts3 Track Member Join Date: May 2018 Location: Farmington Hills, MI Posts: 599 Drives: 08 Expedition Rep Power: 6765	What is making you call it a low voltage condition? If your alternator is on it's way out, I'm curious if maybe it actually caused a voltage spike that blew your starter motor. If this is what happened, anything that's got a 12v line is in theory fair game. In the lab, we've ESD'd circuit boards that have failed in such a way that makes it hard to figure out what has happened. They would half-way work, but do all kinds of crazy ****. We had one case where a voltage spike killed a capacitor on a circuit board, but it failed closed (causing a short). This in turn caused it to destroy any other electronic hardware that it was plugged in to... almost like a hardware (as opposed to software) computer virus. I mention all of this to point out that transient voltage spikes can ruin things in very unexpected ways. Hopefully it can be diagnosed without spending money replacing many things. JSur likes this.

11-12-2018, 10:36 AM	#4 (permalink)
mults A True Z Fanatic Join Date: Aug 2011 Location: Cleveland, OH Age: 70 Posts: 1,830 Drives: 2010 (40th) #706 Rep Power: 16886	I am curious about your term "the starter fried". Did it smoke and need to be replaced, or have other symptoms? As-far-as low voltage, it can be many things...Are any of the wires close to the hot components of your TT setup that could have melted? How low does the voltage get when you say "low voltage"? Is the voltage measured at the battery, or are you going from the voltmeter? Electrical issues are undoubtedly the hardest to track down. Keep us posted as to any other symptoms or fixes... __________________ mults 40th Anniversary 'Z', 312.06HP/260.58TQ (Dynosty EcuTek Tune) Build Date/Number: 1/27/2010 #706 Berk HFC + CBE, R2C CAI, Clear Bra, Cleveland Z Club

11-12-2018, 11:18 AM	#6 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	The starter shouldn't be the problem. Alternator - maybe; but it sounds like it's charging the battery, so it's low on my list at this point. Since the battery is discharging, I suspect an intermittent short; possibly related to the turbo install. Check system voltage with a meter. A recording meter will help spot intermittent problems. Edit: Didn't fully read previous post. You have low voltage, so the alternator jumps to the top of my list. Ghostvette and JSur like this. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

11-12-2018, 12:01 PM	#7 (permalink)
bunk A True Z Fanatic Join Date: Mar 2018 Location: Southern California Posts: 4,077 Drives: 2010 370z Roadster Rep Power: 2684369	FWIW, on my gf's focus, the engine would rev close to stalling when idling and you turn on the AC. Couldnt figure it out til the starter gave out, and found a frayed battery cable. __________________ -Drop in K&N Filter -Invidia Gemini CBE -Z1 Oil Cooler -Swift Springs - EcuTek -Forgestar F14 -SPL Camber Links -Akebono BBK Upgrade -Z1 Premium SS Lines -SPL Diff Bushings -SPL FUCAs - BellRaceworks Diff Brace

11-12-2018, 01:49 PM	#10 (permalink)
bunk A True Z Fanatic Join Date: Mar 2018 Location: Southern California Posts: 4,077 Drives: 2010 370z Roadster Rep Power: 2684369	Yeah, if your TT setup makes things a little tight in the engine bay, Id check the battery cables for frays or any oil/fluid leaks that may have sprayed into your starter or alternator. JSur likes this. __________________ -Drop in K&N Filter -Invidia Gemini CBE -Z1 Oil Cooler -Swift Springs - EcuTek -Forgestar F14 -SPL Camber Links -Akebono BBK Upgrade -Z1 Premium SS Lines -SPL Diff Bushings -SPL FUCAs - BellRaceworks Diff Brace