High Load % continued-

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NJaykaplan

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Made a new thread because my old one's title was kind of misleading. I still believe i have a vacuum leak, just because of never having one in this car and with how rough we have been with some of the jobs lol. But my main problem is a high load % at idle. I believe 60% with a/c, 50% without. Car has had a ton of work done since october. Most recently ive had to deal with electrical issues (alt and battery), but voltage doesnt seem to affect it much, unless the actual electronics are seeing MUCH lower voltage than the car is showing. Changed the battery and still in the process of finding an alternator, but driving the voltage is 13 to 13.3 and at idle slightly less. But the load, while driving, is normally high if i'm on the throttle and if i let off and coast, it will drop to 25-35%, but if i touch the gas it will shoot back up to 60-80%.


From my other thread, i am definitely changing the iac and tps. I have had an oil leak a while, and had complaints, so first i will get it on a lift and have the oil filter adapter done, along with new motorcraft o2s. I'm nervous about the iac and tps, because it does idle nice at the moment, but i have been one of the lucky few to receive a dead iac in the box before so i'm skeptical about this one. Going to pay someone on the side to do the work for me, good enough pricing where nobody would think of doing it themself, but all i find on the internet is that the load % is based on the maf mainly, also saw it looks at TPS as well, but it does look normal on a scanner and doesnt throw any codes. I will change both IAC and TPS only because there is 142k on the motor, and it has to take 5k miles a month, so i cant leave room to get stuck anywhere.

Main point of my new thread was the title on this thread might get some people who have had similar problems, or gone through the same and solved it. If i get anyone new in here, i'll list all the work done to the car, but for the most part common mark viii things have not been touched yet.
 
Just seeking a bit of clarification, your "%load" must be electrical system load? If so, does the system tell you draw in Amps, rather than percentage? (percentage could vary with alternator size, as well as the battery, I suppose)

Assuming electrical load, your alternator may well be part of the problem. I know you are attempting to address that already though. Just for kicks, I just went out to the parking lot and put a voltmeter on my own (97) at the battery terminals.

idle - no fan, no ac, no radio. 13.2v
idle - fan on, ac on, no radio. 12.4v
idle - fan on, no ac, no radio. 13.0v

I have never replaced this alternator, so it has at least 100,000 miles on it. Although everything I've learned about alternators says that this is low, and that I should see 13.8v, up to 14.4, my numbers seem to match yours, and I've never witnessed any problems with the operation of my car.

I don't have an ammeter here at work, so I cannot do anything approximating an actual load test. Still, 60% of the rated capacity (120A, stock alternator) sounds pretty normal to me. I can't help but wonder if we're chasing ghosts here.

Do you have a high-end audio system in the car? Those can draw some serious power.

Mods / smarter folks. If I'm way off the mark here, feel free to delete this for the purposes of clarification. I'd hate to be muddying the waters.
 
tixer said:
Just seeking a bit of clarification, your "%load" must be electrical system load? If so, does the system tell you draw in Amps, rather than percentage? (percentage could vary with alternator size, as well as the battery, I suppose)

Assuming electrical load, your alternator may well be part of the problem. I know you are attempting to address that already though. Just for kicks, I just went out to the parking lot and put a voltmeter on my own (97) at the battery terminals.

idle - no fan, no ac, no radio. 13.2v
idle - fan on, ac on, no radio. 12.4v
idle - fan on, no ac, no radio. 13.0v

I have never replaced this alternator, so it has at least 100,000 miles on it. Although everything I've learned about alternators says that this is low, and that I should see 13.8v, up to 14.4, my numbers seem to match yours, and I've never witnessed any problems with the operation of my car.

I don't have an ammeter here at work, so I cannot do anything approximating an actual load test. Still, 60% of the rated capacity (120A, stock alternator) sounds pretty normal to me. I can't help but wonder if we're chasing ghosts here.

Do you have a high-end audio system in the car? Those can draw some serious power.

Mods / smarter folks. If I'm way off the mark here, feel free to delete this for the purposes of clarification. I'd hate to be muddying the waters.
Click to expand...

Actually that is pretty helpful, but the load % i have an issue with is the engine load %. So maybe my alternator is not dieing, maybe i just never watched it closely and it is cutting off at those times, i do know they don't charge all the time.. I don't have anything added to my car. Removed air suspension as well so thats one less draw. But i'm in south florida, i have the fan as well as a/c on at all times, then at night the draw is even more. I just had to replace a everstart maxx after 10 months, so i dont think something is right, I'm going to try to get my hands on an alt that will keep my system above 14, probably getting a better battery as well since i dont wanna stick with the walmart battery, and see if that drops my engine load % at all. After testing the maf, it is at about .8 volts at idle and 4.2 at WOT.
 
I didn't think about the air suspension. it is quite possible that my pump was operating during part of that test. That's a good point.

The battery is generally your "reserve," but I have an old Minnesota habit of buying the largest battery available. Even though I store this car in winters, mine has a battery good for over 1000 CCA. Perhaps that could help even out a weak alternator, as long as it charges at some point.

I did observe voltages climb slightly as I revved the engine by tugging on the throttle cable, but I didn't want to spend much time doing that here at the office. :)

Edit: it is 82 degrees Fahrenheit right now, where I am
 
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Your battery voltage is good, but i dont know about my 11.75. But who knows, mine was at night with headlights. I'm just gonna go with the tps and iac for now hopefully.

(Edit: Gonna have an alt built too obviously)
 
Walmart just warrantied out their gold battery because of a dead cell after 10 months, so i was watching on my new one to make sure its getting charged properly. 11.75 was at idle at a light, idling at 600 rpm with headlights, fan, a/c with a brand new battery from walmart, group 65 no less lol.
 
Here's what you need to do to analyze the charging system with no test equipment except a digital volt meter...

1. Engine off - battery standing voltage.
With the engine off and fully charged battery, hook up the meter directly to the battery terminals(not clamp, bolt, nut, etc...). Read the meter as volts DC.

2. Engine running - lo idle - no load charging voltage.
Engine running at idle, all lights, accessories and AC off. Read the meter after voltage stabilizes from starting engine.

3. Engine running - hi idle - no load charging voltage.
Engine running at 1500 RPM, all lights, accessories and AC off. Read the meter.

4. Engine running - full load charging voltage.
Engine running at 2000 RPM, lights on high beams, AC on MAX(blower on high), radio on, etc... Read the meter.

These readings give a good indication of the charging system. Take these readings and let us know.
 
driller said:
Here's what you need to do to analyze the charging system with no test equipment except a digital volt meter...

1. Engine off - battery standing voltage.
With the engine off and fully charged battery, hook up the meter directly to the battery terminals(not clamp, bolt, nut, etc...). Read the meter as volts DC.

2. Engine running - lo idle - no load charging voltage.
Engine running at idle, all lights, accessories and AC off. Read the meter after voltage stabilizes from starting engine.

3. Engine running - hi idle - no load charging voltage.
Engine running at 1500 RPM, all lights, accessories and AC off. Read the meter.

4. Engine running - full load charging voltage.
Engine running at 2000 RPM, lights on high beams, AC on MAX(blower on high), radio on, etc... Read the meter.

These readings give a good indication of the charging system. Take these readings and let us know.
Click to expand...

I will have to do it in the morning, its been pouring on and off again tonight, just got off work. I have not watched directly to the battery other than to check it after i turn off the car and its normally full, 12.85. Even the old battery showed 12.8 when i turned off the car, but when i had any draw it would drop slowly down to 10v. Walmart gave me a brand new battery since it was still under warranty even though i had no receipt, and i decided to datalog again with the sct software to watch certain things, and this time since the battery issue i had voltage up as well, and the lowest i showed was 11.75 and the highest was 13.38. I assume i happened to look at idle at one of the times the alt turned off, but i dont like the car ever dipping below 12 and i would be much happier with a voltage above 14. I could get a junkyard alt, but if i can get something custom built for a reasonable price i'm definitely going with that route. Most likely i will also pick up a battery meant for car audio, so i will get a higher voltage and if i get the one i'm looking at, should run the car for days if my alt ever does die lol. But i'm still stumped as far as the engine load % goes. I have not really been able to correlate my load % with any other sensors on my car, so basically i will throw parts at it until it goes down as horrible as this sounds at this point.

(But to answer your question, not as detailed but i will definitely do it in the morning, the alt is charging at idle enough for the car but not accessories. It will be draining battery power, which i would consider any drop below 12.6, with anything more than my radio running at idle. Once i am moving, it is no problems at all, and i verified it is not because of a low idle. The 11.75 drop was at 650 rpms verified on a actron scanner)
 
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Any updates? I can grab a junkyard alternator locally if you're interested. $100 shipped, there's two available that I can pull.
 
Its been pouring here every day, and i have no garage to really work with. Most of the time when i turn it off, it is at 12.8 or 12.9, only once was it 12.3 and i've just stuck the battery on a charger. I'm gonna do the tps, o2s, try to work down that load %, then if i still notice my batterys not fully charged after a ride i'm gonna get a custom alternator built so if i want to get back into car audio, i'll have plenty of alternator headroom lol. I appreciate it J, now i've slowed down working on my car because of the weather and my works been pretty busy. Gonna hopefully start again Monday.
 
No worries. A typical battery will be 12.4 "standing" volts. Anything close to that is okay, below 12 and I would start worrying that the battery has a bad cell. Typically I've found that I can start a car as long as it has a minimum of 9+ volts.
 
Old owner had purchased a walmart evermaxx gold battery, so they warrantied out my last battery which did indeed have a bad cell a few days ago. I really am thinking that the alternator is not as strong as needed, but if i do replace it, i want something that will keep me above 14 volts. Only time i see bad voltage drop is when i idle for a long time, i deliver food in my lincoln so it will spend a good amount of time idling. My plan with the alternator, once i have the funds, is to have one built that will do 100 at idle and i don't really care about the max amperage lol. I know it'll be kinda pricey, If i can get one that'll do 250 max and 100 idle for the ballpark of $300 i'd be happy. I used to do a ton of car audio, and as soon as i have time and no more maintenance or repairs to do, i will be installing some badass jbl components that'll take 200+rms each.

As far as the engine load % goes, i'm gonna basically replace anything i think could affect it. Worst case, i'll have a handful of backup parts for my next mark viii, either way i'll be stickin with a mark anyway.
 
Anything above 14 volts isn't normal just FYI. :)

When I was having issues at idle I just got a smaller pulley for my alternator. Solved the problem there.
 
The smaller pulley is actually an amazing idea and i cant believe i've never thought of that, even if its only until i upgrade alternators. Normally when i switch from a regular car battery to a deep cycle agm (Battery meant for heavy car audio use), i went from mid 13s to mid 14s. I'd like to hold a steady 14 so even with a drop, all electronics will see at least 12.
 
Its alright. I've had serious charging problems in the past, so this time i'm definitely gonna take preventive steps and change my alternator. And pigtail of course, everytime i have an alt die and don't change that little part, it eats up my new alt lol.
 
I would suspect it's more of a universal style. Most of the port holes are the same but your issue would come in the "throw" length of the piston inside. It probably won't match the computers input/signal.
 
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