Friday, December 05, 2014 - 09:40 pm, by: Rob Charles(Pearl_white)
Hey guys,
Curious.
Can a bad alternator cause the car to have a high RPM? Similar to an IACV being stuck or vac leak?
I've been dealing with High idle upon initial start up randomly, and losing power steering fluid. Also, sometimes i go to take off, and have a lack of power. Putting 2 and 2 together here...
Rundown of my issues: 1. High idle in park and neutral, 1100rpm in D. Happens randomly upon initial start up - and won't go down when warm.
2. Small power steering fluid leak.
3. Lack of power when flooring it from a stop, even when in 1st. No idea when it will decide to rob me of power. Usually is worse when the idle is higher.
Side note - When idling normally, car is fine. Will idle at 700rpm in D. When the car decides to idle too high however: If tps is set clockwise, the car will idle surge from 1000-2200rpm over and over. It also has throttle delay. When tps is in the middle, the car revs itself to 3000rpm in park. A stable 3000rpm. no delay when pushing accelerator. When tps is anticlockwise, it's the same as middle I think...
Also, I'll get a lack of power with the high idle.
What happened today: I started the Soarer in driveway,it was in park - It revved at 1100rpm -crept to 1300rpm. (was cold). Went under the hood for 1 min or so - checking vac lines and so on, again. Took a pic of the engine also. Everything was great from what I could see. When i got back in the car, the Dash had an "alternator not charging" message waiting for me. Turned Soarer off.
Turned it back on and it started idling at 3000rpm. (it woulda had a surging idle if the TPS was set more clockwise.) Noticed the "alternator not charging" message was gone.
Turned Soarer off. Put the key to "on" (i didnt start engine), and i noticed that I now have the cat overheat light staying on, after all other lights turned off.
Started Soarer again - 3000rpm - no messages and cat light off. Turned Soarer off.
Cracked the sh!ts and went inside.
And here we are.
Sooo....
We know that usually it's the IACV that causes a high idle/surging idle, or a vac leak or ecu or so on...
Can a bad alternator also cause a high idle, or what's the go there?
Bonus question: Can a bad alternator turn your beast into a slug?
Saturday, December 06, 2014 - 08:30 am, by: Jamie Richards(Nwb40gt)
Quick way to check your alternator, is to start car then pull the positive battery terminal, if car shuts down alternator is bad if engine still runs Its good
Saturday, December 06, 2014 - 09:52 am, by: Tom Richards(Tomr)
multi meter should read ~14.3v if charging ok. if no meter, turn headlights on and check if they get brighter with revs. I would be surprised if the alternator is causing your problems.
Saturday, December 06, 2014 - 06:11 pm, by: Scott Vim(1uz1jz)
Cat light means nothing if he car isn't running. Mine does the same. You're taking too many random guesses Rob and using unusual logic like the tyres make a sound could this be related to engine idle.
Saturday, December 06, 2014 - 10:11 pm, by: Rob Charles(Pearl_white)
Thanks for the replies people.
Scotty! "Sometimes you gotta think outside the square. The Soarer is not a 1992 EB Falcon"
I did notice tonight that - If the car is running with headlights on - The dash will dim slightly when foots on the brake or a blinker is on. If brightness is 10, it dims to a 9.
Also - When lights are on and I try move the seat, it used to go very slow... Or that's how it was last month anyway... Seats been fine for a while now ~
I also have a speaker whine - matching engine RPM. This is probably the alternator, as i've already changed head unit...
Would power steering fluid cause the alternator diode to die as such - and cause speaker whine? Or is it likely to just blow it instead?
I'm aware the power steering fluid leaks into the alternator of these cars (v8's), but would it be an instant short, or would you first get alternator whine through speakers, then electrical issues - then it finally dies?
On a side note I read that: If your battery is in a state that it doesn’t accept a charge, and your alternator is fooled into thinking that the battery is fully charged, then your performance (acceleration) will be affected due to inadequate voltage to the ignition coil(s). Having said that – it is somewhat rare for this to occur.
Also read on another Soarer forum - but can't find link: If your alternator is wonky (or battery), you may cause issues with the cats due to unburnt fuel or something + you will have a lack of acceleration as there is a non good supply of power to set the electrical sensors and everything...
It was something like that.
I'll get back to you tomorrow with multimeter readings!
Just for the record - what should the absolute minimum battery charge be? Also, what should the minimum alternator charge be for the v8?
Sunday, December 07, 2014 - 05:55 am, by: Tom Richards(Tomr)
if you have whine in the speakers , you have a stuffed phase in the alternator. replacement rectifier is ~$70 off david @ http://stores.ebay.com.au/startercenter/.
Monday, December 15, 2014 - 06:16 pm, by: Rob Charles(Pearl_white)
So - worked out that the high idle is caused from the power steering fluid being low.
When power steering fluid is full, car behaves perfectly.
When power steering fluid is low, it idles high - or idle surges.
I assume this is due to a vacuum leak which happens when fluid is low - possibly it's plugging a gap or something...
So yeah - at least that is sorted so far.
Lots of fluid means no high idle. Lack of fluid mean high idle.
Hopefully it's just the pressure switch - a cheap fix - that would explain why there are no leaks under car or on any bits inside the bay. It's being sucked into the intake.
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