Voltage oscillation/drop during WOT pulls…… V swings between 13.8 to 12.3V
Oct 13, 2013, 06:28 PM
#1
Voltage oscillation/drop during WOT pulls…… V swings between 13.8 to 12.3V
Jan 4th, 2015 Update:
Update: I just went through an engine build, so I couldn’t resist swapping the alternator to a new unit. Unfortunatly it wasn’t oem, however, it was from a local auto parts store that a friend recommended as he had used it and seen good results. Link below
http://www.oreillyauto.com/site/c/de...ord=alternator
Currently the behavior as follows;
Idle with headlights OFF is ~13.4-13.7 V
Idle with headlights ON is ~12.4-13.0 V
So you can imagine at night while coming to a stop it becomes tricky to keep the engine alive.
Things I have done so far;
1) Tried multiple alternators 1 used oem and the latest is brand new from a local store.
2) Added 3 additional grounds to the engine….2 on thermostat housing and 1 on one of the exhaust manifold studs.
3) Added a direct 10 gauge wire from the positive terminal of the battery to the alternator to rule out a bad harness.
4) Replaced the mini battery as well, but it doesn’t get driven much so I usually leave it on the charger prior to drives.
The car is fully built now on speed density with a double pumper.
I can’t think of anything else to try to improve this aside from maybe adding an additional ground directly to the alternator. It is worth mentioning that I had to delete the ground that typical goes on the intake manifold due to running an AMS F1.
Screen shot below shows the difference in the engine voltage via evoscan with and without the headlights during a warm idle.
Any other recommendations?
Thanks
Archive post:
Hello,
So I am running into an issue where my battery voltage swing between high 13’s to low 12’s whenever I am under a heavy load between 5k rpm to redline. I have added 4 additional grounds to the block, checked the positive terminal on the alternator, and replaced the mini battery with a new one yet I am still running into the issue. Obviously this is throwing my injectors off ......so its been a real pain!.... any idea what It may be? Could it be the actual alternator?
Sometimes at idle if I turn on the headlights it could stall the engine. This is while setting the idle target at 1182rpm and ~20* worth of spark.
On a side note, I did spew some oil on the alternator coil in the past due to an oil leak in the past, so not sure if having some oil residues could impact this.
Your input is appreciated!
Thanks
Mod list: ROM 941 SD, E85, dual walboro, FIC1450, Sparktech Pro-CDI, and all supporting mods.
Update: I just went through an engine build, so I couldn’t resist swapping the alternator to a new unit. Unfortunatly it wasn’t oem, however, it was from a local auto parts store that a friend recommended as he had used it and seen good results. Link below
http://www.oreillyauto.com/site/c/de...ord=alternator
Currently the behavior as follows;
Idle with headlights OFF is ~13.4-13.7 V
Idle with headlights ON is ~12.4-13.0 V
So you can imagine at night while coming to a stop it becomes tricky to keep the engine alive.
Things I have done so far;
1) Tried multiple alternators 1 used oem and the latest is brand new from a local store.
2) Added 3 additional grounds to the engine….2 on thermostat housing and 1 on one of the exhaust manifold studs.
3) Added a direct 10 gauge wire from the positive terminal of the battery to the alternator to rule out a bad harness.
4) Replaced the mini battery as well, but it doesn’t get driven much so I usually leave it on the charger prior to drives.
The car is fully built now on speed density with a double pumper.
I can’t think of anything else to try to improve this aside from maybe adding an additional ground directly to the alternator. It is worth mentioning that I had to delete the ground that typical goes on the intake manifold due to running an AMS F1.
Screen shot below shows the difference in the engine voltage via evoscan with and without the headlights during a warm idle.
Any other recommendations?
Thanks
Archive post:
Hello,
So I am running into an issue where my battery voltage swing between high 13’s to low 12’s whenever I am under a heavy load between 5k rpm to redline. I have added 4 additional grounds to the block, checked the positive terminal on the alternator, and replaced the mini battery with a new one yet I am still running into the issue. Obviously this is throwing my injectors off ......so its been a real pain!.... any idea what It may be? Could it be the actual alternator?
Sometimes at idle if I turn on the headlights it could stall the engine. This is while setting the idle target at 1182rpm and ~20* worth of spark.
On a side note, I did spew some oil on the alternator coil in the past due to an oil leak in the past, so not sure if having some oil residues could impact this.
Your input is appreciated!
Thanks
Mod list: ROM 941 SD, E85, dual walboro, FIC1450, Sparktech Pro-CDI, and all supporting mods.
Last edited by detroit pistins; Jan 4, 2015 at 08:24 PM.
Oct 13, 2013, 06:44 PM
#2
Oil will definitely create resistance in the alternator's windings.
I would think simple though, check your acc belt tension and make sure the belt and pulley are dry and not slipping. Could very well be that the torque from your engine is not allowing for the belt to keep up. I would rev the car up to about 4.5k -5k with little load on the engine so the chance of the belt slipping is minimal.
Perform a voltage drop test from the alternator's B+ post to the positive battery terminal and from the B+ post to the alternator's ground. Just to insure that you have good connections.
Good luck man!
I would think simple though, check your acc belt tension and make sure the belt and pulley are dry and not slipping. Could very well be that the torque from your engine is not allowing for the belt to keep up. I would rev the car up to about 4.5k -5k with little load on the engine so the chance of the belt slipping is minimal.
Perform a voltage drop test from the alternator's B+ post to the positive battery terminal and from the B+ post to the alternator's ground. Just to insure that you have good connections.
Good luck man!
Oct 13, 2013, 07:13 PM
#4
hiboost2.0,
Thanks for your input. I checked the tension on the belt and its condition and they both seem to be tight and clean/dry. I also went to the local hardware store, and had them help me perform a voltage drop test and this is what came up…
1) While the car is idling (with the headlights off), we put a load on the engine so the idle rpm dropped to possibly 1k from 1150 and it reported that the alternator was supplying ~50amps.
2) Then we performed the same test and while at it, we turned on the headlights and the engine died. If I remember correctly, the alternator tried to supply ~ 90amps but couldn’t keep up.
At the end of the test, the technician was debating whether it’s the alternator or not. He mentioned that it could be!
Is that a similar load test you’re referring to? I am not familiar with the test you mentioned above.
Thanks
Thanks for your input. I checked the tension on the belt and its condition and they both seem to be tight and clean/dry. I also went to the local hardware store, and had them help me perform a voltage drop test and this is what came up…
1) While the car is idling (with the headlights off), we put a load on the engine so the idle rpm dropped to possibly 1k from 1150 and it reported that the alternator was supplying ~50amps.
2) Then we performed the same test and while at it, we turned on the headlights and the engine died. If I remember correctly, the alternator tried to supply ~ 90amps but couldn’t keep up.
At the end of the test, the technician was debating whether it’s the alternator or not. He mentioned that it could be!
Is that a similar load test you’re referring to? I am not familiar with the test you mentioned above.
Thanks
.... I think I am leaning toward this if nothing else comes to mind.
Oct 13, 2013, 08:44 PM
#6
hiboost2.0,
Thanks for your input. I checked the tension on the belt and its condition and they both seem to be tight and clean/dry. I also went to the local hardware store, and had them help me perform a voltage drop test and this is what came up…
1) While the car is idling (with the headlights off), we put a load on the engine so the idle rpm dropped to possibly 1k from 1150 and it reported that the alternator was supplying ~50amps.
2) Then we performed the same test and while at it, we turned on the headlights and the engine died. If I remember correctly, the alternator tried to supply ~ 90amps but couldn’t keep up.
At the end of the test, the technician was debating whether it’s the alternator or not. He mentioned that it could be!
Is that a similar load test you’re referring to? I am not familiar with the test you mentioned above.
Thanks
Thanks for your input. I checked the tension on the belt and its condition and they both seem to be tight and clean/dry. I also went to the local hardware store, and had them help me perform a voltage drop test and this is what came up…
1) While the car is idling (with the headlights off), we put a load on the engine so the idle rpm dropped to possibly 1k from 1150 and it reported that the alternator was supplying ~50amps.
2) Then we performed the same test and while at it, we turned on the headlights and the engine died. If I remember correctly, the alternator tried to supply ~ 90amps but couldn’t keep up.
At the end of the test, the technician was debating whether it’s the alternator or not. He mentioned that it could be!
Is that a similar load test you’re referring to? I am not familiar with the test you mentioned above.
Thanks
Oct 13, 2013, 09:37 PM
#7
Most batteries will show a voltage of ~12.8V with the car off. If you are seeing 13.8v or more with the car running, then the alternator is charging the battery. Are you using a deep cycle mini battery? It's normal for the voltage to drop under WOT.
Why do you think this is throwing your injectors off?
The car dying when you turn your lights on may be attributed to changes you've done to the idle rather than the alternator and battery.
The current increase when the lights are on is expected. When you turn more electrical devices on in the car the amount of current used will increase.
Oil on the coils will not affect the alternator, but if you get oil into the voltage regulator that might be a problem.
Why do you think this is throwing your injectors off?
The car dying when you turn your lights on may be attributed to changes you've done to the idle rather than the alternator and battery.
The current increase when the lights are on is expected. When you turn more electrical devices on in the car the amount of current used will increase.
Oil on the coils will not affect the alternator, but if you get oil into the voltage regulator that might be a problem.
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Oct 14, 2013, 07:22 AM
#8
Latencies are a function of voltage so I am tunning for a healthy system and when these drops occur which arent accounted for, it throws my targets off.
I am with u on the current demand, but I am not sure if there is a calibration that would compensate for the demand. Maybe there is and I am not aware of it in ECUFLASH.
Thanks
I am with u on the current demand, but I am not sure if there is a calibration that would compensate for the demand. Maybe there is and I am not aware of it in ECUFLASH.
Thanks
Oct 14, 2013, 08:12 AM
#10
if the latency is set accurately, voltage should have minimal effect on injector performance. it would have an impact on fuel flow for a fuel pump at its limit, but since you have a double pumper, i'd guess that you're ok for your power level. with that said, if i were you, i'd be trying to figure it out too. i say swap out the alt. one thing i remember from reading on evom is that the dealer-supplied replacement alternator is not as good as the original one. suggest sourcing an orig from a junkyard.
one thing to watch with idle issues on 8's is that the idle timing needs to be set to 5 deg. this is because the ecu defaults to 5 deg if rpm dips below 438 rpm. a step change from 20 -> 5 deg will kill it pretty much every time if idle happens to momentarily get pushed below.
one thing to watch with idle issues on 8's is that the idle timing needs to be set to 5 deg. this is because the ecu defaults to 5 deg if rpm dips below 438 rpm. a step change from 20 -> 5 deg will kill it pretty much every time if idle happens to momentarily get pushed below.
Nov 13, 2013, 12:48 PM
#12
Update: I took out the alternator, and had it tested at the local autoparts store and it passed thier test. Not sure what else to check for!.... Any input is welcome!
I have a spare alternator that i sourced localy (oem) and may try that out.
Thx
I have a spare alternator that i sourced localy (oem) and may try that out.
Thx
Apr 7, 2014, 06:55 AM
#13
Update:
I ended up swapping the alternator to another unit and currently experiencing similar results. Granted the alternator was a used unit, so it could be that it’s a faulty unit as well. I will share some data later to show what I am experiencing (12.3 to 14V).
What voltage do you guys see under heavy loads/Wot?
I ended up swapping the alternator to another unit and currently experiencing similar results. Granted the alternator was a used unit, so it could be that it’s a faulty unit as well. I will share some data later to show what I am experiencing (12.3 to 14V).
What voltage do you guys see under heavy loads/Wot?
Apr 7, 2014, 08:46 AM
#14
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Not to thread jack (sorry) because this is definitely related. I have 115k miles now and occasionally I notice that the headlights dim and what not. I want to replace my alternator before I HAVE to and have been looking for an oem alternative since the ones they sell now aren't as good as the actual oem one on my IX. I found this on eBay, please don't scortch me for eBay lol I'm just wondering if anyone has any input they can add on this "high output" alternator????
http://pages.ebay.com/motors/link/?n...d=251351875484
http://pages.ebay.com/motors/link/?n...d=251351875484
Apr 7, 2014, 06:57 PM
#15
Aside from the 2.0l alternator, have you looked into the 2.4l units that are available for the lancer and outlanders? I am curious if those would fit or may need some modifications with regards to sizing of the pulley. They claim to be 220amp vs our stocker which I think is 180 amp.
http://www.ebay.com/itm/ALTERNATOR-HIGH-OUTPUT-MITSUBISHI-LANCER-OUTLANDER-2-4L-2004-2006-220AMP-/261093166030?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AOutlander&hash=item3cca5d8bce&vxp=mtr
http://www.ebay.com/itm/ALTERNATOR-HIGH-OUTPUT-MITSUBISHI-LANCER-OUTLANDER-2-4L-2004-2006-220AMP-/261093166030?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AOutlander&hash=item3cca5d8bce&vxp=mtr