Voltage/Alternator drop off at WOT..
Voltage/Alternator drop off at WOT.. I have a 2000 Z28 Camaro, with the stall converter, ud pulley and only an alt.
the motor tends to rev quickly
Problem is when I make a pass at WOT sometimes the voltage drops off for a split second and doesn't charge. Chargin at idle is perfect, the problem only shows when I floor it , rpms rise quicky, and voltage drops, then comes back on .
its as if someone unplugs the alt. for 1 sec.
I noticed the alt. signal wire comes from the computer...has anyone wired it straight to the battery?
the motor tends to rev quickly
Problem is when I make a pass at WOT sometimes the voltage drops off for a split second and doesn't charge. Chargin at idle is perfect, the problem only shows when I floor it , rpms rise quicky, and voltage drops, then comes back on .
its as if someone unplugs the alt. for 1 sec.
I noticed the alt. signal wire comes from the computer...has anyone wired it straight to the battery?
Is there an actual problem asociated with the momentary voltage drop? If your engine revs quickly, it may take your regulator a few seconds to catch up/balance out. It seems that your battery's normal 12 volts will cover the second that your alternator doesn't.
Sounds like a belt problem, particularly if you are running a different pulley on the alt.
If you are racing with specialized pullies, you'll want something like this to make sure you are keeping the proper tension: https://ls1tech.com/forums/generatio...ame-price.html
If you have a stock tensioner, you are relying on its spring to keep tension, which may not hold up under the shock of accelerating quickly.
If you are racing with specialized pullies, you'll want something like this to make sure you are keeping the proper tension: https://ls1tech.com/forums/generatio...ame-price.html
If you have a stock tensioner, you are relying on its spring to keep tension, which may not hold up under the shock of accelerating quickly.
The alt. "ON" wire comes from the computer...maybe the computer is sensing a slight voltage spike..or is tuning this wire off for a moment...
here is a pretty good wiring schematic...
I wonder if its a good idea to wire to a "key on" relay and to the battery, to try and bypass computer control...
I guess before I go swapping alternators I'll back probe the signal wire and see if it looses voltage at wot...if so then the alt. should be good and will just need a separate signal setup
http://chevythunder.com/19992002_ls1...s.htm#Charging System Schematics
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Brett Foote Hell - your alternator is so accessible, why don't you just pop it off and take it to an auto parts store to be tested. That will tell you instantly what kind of shape its in.
Do you have any accessories that draw a lot of power or notice any difference when the head lights are on/off? If not, then you should be fine unless something is defective.
How many miles are on it?
Do you have any accessories that draw a lot of power or notice any difference when the head lights are on/off? If not, then you should be fine unless something is defective.
How many miles are on it?
Hell - your alternator is so accessible, why don't you just pop it off and take it to an auto parts store to be tested. That will tell you instantly what kind of shape its in.
Do you have any accessories that draw a lot of power or notice any difference when the head lights are on/off? If not, then you should be fine unless something is defective.
How many miles are on it?
Do you have any accessories that draw a lot of power or notice any difference when the head lights are on/off? If not, then you should be fine unless something is defective.
How many miles are on it?
it only does it during a wot snap....if I roll into the throttle everything is on!
I'll prob the signal wire, its the only way to find out for sure if the alternator is being shut off, or if its shorting itself out.....
https://ls1tech.com/forums/generatio...-failures.html
if the alt cant keep up with what little load you have on it............its the alt.......and IMO the stock alt CANNOT keep with our cars .........a design failure by GM
if the alt cant keep up with what little load you have on it............its the alt.......and IMO the stock alt CANNOT keep with our cars .........a design failure by GM
However... your alternator is spinning slower at a given RPM range due to the UD pulley. This could be at the root of the issue but I'd still get the alternator checked first. Its not unheard of for voltage regulators to go bad quickly, especially if it was a reman. (For the record, I will never buy a reman alternator again. Too many problems in past cars.)
It looks like the alternator is the only belt driven accessory left, right? If so, and if your alternator tests out good, I'd go back to the stock pulley and see what happens. Buying a larger alternator may also solve the problem with the UD pulley on, but it WILL suck more energy from the engine to turn it. (I assume this would be a bad thing in your situation.)
BTW - I don't think your exciter wire is the issue. Its main function is to get the alternator going. Once its turning and generating power, it should keep things going internally: http://en.wikipedia.org/wiki/Alterna...ve_alternators
Last edited by wssix99; Dec 3, 2011 at 09:03 AM. Reason: grammar
On The Tree
Joined: Sep 2004
Posts: 178
Likes: 0
From: ALBUQUERQUE, NM
I have a 2000 Z28 Camaro, with the stall converter, ud pulley and only an alt.
the motor tends to rev quickly
Problem is when I make a pass at WOT sometimes the voltage drops off for a split second and doesn't charge. Chargin at idle is perfect, the problem only shows when I floor it , rpms rise quicky, and voltage drops, then comes back on .
its as if someone unplugs the alt. for 1 sec.
I noticed the alt. signal wire comes from the computer...has anyone wired it straight to the battery?
the motor tends to rev quickly
Problem is when I make a pass at WOT sometimes the voltage drops off for a split second and doesn't charge. Chargin at idle is perfect, the problem only shows when I floor it , rpms rise quicky, and voltage drops, then comes back on .
its as if someone unplugs the alt. for 1 sec.
I noticed the alt. signal wire comes from the computer...has anyone wired it straight to the battery?
Thread Resurrection!
1995 LT1 trans am.......doing this same thing. At idle or cruise rpm, voltage is fine. WOT or quick rise in rpm, voltage drops to 8-9. Belt tension is fine.
Took alternator in today (OEM alternator)........alternator tested fine.
I inspected the exciter wire, it looks fine.
Any ideas? Trying to avoid spending $150 on an alternator if I can.
Launching!
Joined: Mar 2004
Posts: 223
Likes: 0
From: Apple Maggot Quarantine Zone
Are you sure that this isn't built into the design of the car? I know that the computer is programmed to drop out the AC compressor at WOT, to free up more power. Makes sense that they would unload the alternator as well...
Possible, but I kinda doubt thats it. If it were he should see problems throughout the RPM range and not just WOT. Plus it would be obvious when he cranks the vehicle too. Also my stock alt will run my 99 Z28 at 13.5 Volts on a dead battery no issues, done it before... not RECOMMENDED, but it will work.
Trust me when I say after multiple WOT experiences, dumping alt power and risking frying sensitive components was NOT apart of the design. (you risk taking out components with too low of voltage just as much as you do with too high aswell, my power windows literally caught fire when my exciter wire was broken without my knowing and the alt died with it)
----------------
To the OP I may have missed it but when did these problems start? I notice UD Pulley, Electric WP, and what appears to be a stock alternator. Im pretty sure the alt in this configuration is getting more than its fair share. I'd just upgrade to a truck alt at the minimum, even if it doesn't solve the issue... it's extra insurance.
If its not the alt failing, its the belt and pulleys. Only other thing it could be really. It "sounds" like your belt is slipping alittle bit at WOT due to the increased inertia with much less resistance (less pulleys / UD pulley) plus the shock of force thats presented in the short instance of going WOT.. Try doing this... Slowly ease the car into WOT, as in just gradually press the pedal until the car goes WOT and dont just stomp on the gas, see if the issue is still present when you reach WOT. If it is, it's the alt. If it isn't, its the pulley / belt combo.
----------------
To the OP I may have missed it but when did these problems start? I notice UD Pulley, Electric WP, and what appears to be a stock alternator. Im pretty sure the alt in this configuration is getting more than its fair share. I'd just upgrade to a truck alt at the minimum, even if it doesn't solve the issue... it's extra insurance.
If its not the alt failing, its the belt and pulleys. Only other thing it could be really. It "sounds" like your belt is slipping alittle bit at WOT due to the increased inertia with much less resistance (less pulleys / UD pulley) plus the shock of force thats presented in the short instance of going WOT.. Try doing this... Slowly ease the car into WOT, as in just gradually press the pedal until the car goes WOT and dont just stomp on the gas, see if the issue is still present when you reach WOT. If it is, it's the alt. If it isn't, its the pulley / belt combo.
On The Tree
Joined: Sep 2004
Posts: 178
Likes: 0
From: ALBUQUERQUE, NM
I decided to just try and replace the alternator to see what happens.
New alternator, issue is fixed.
I inspected the wiring when I was in there, no obvious issue.
That is a first. I have had alternators fail to charge at low rpm, than charge as rpm increases. Never the other way around.
Not sure what caused it.....maybe a bad internal exciter or regulator? Anyway, happy issue is solved.
New alternator, issue is fixed.
I inspected the wiring when I was in there, no obvious issue.
That is a first. I have had alternators fail to charge at low rpm, than charge as rpm increases. Never the other way around.
Not sure what caused it.....maybe a bad internal exciter or regulator? Anyway, happy issue is solved.
I decided to just try and replace the alternator to see what happens.
New alternator, issue is fixed.
I inspected the wiring when I was in there, no obvious issue.
That is a first. I have had alternators fail to charge at low rpm, than charge as rpm increases. Never the other way around.
Not sure what caused it.....maybe a bad internal exciter or regulator? Anyway, happy issue is solved.
New alternator, issue is fixed.
I inspected the wiring when I was in there, no obvious issue.
That is a first. I have had alternators fail to charge at low rpm, than charge as rpm increases. Never the other way around.
Not sure what caused it.....maybe a bad internal exciter or regulator? Anyway, happy issue is solved.
