Using anything electrical affecting idle? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Mangudai · 03-08-2008, 08:37 PM

Say I turn the steering wheel while im parked, the idle will drop down about 150 rpms then raise up about 100-150 rpm. So if im at 750 and turn the steering wheel the idle will drop down to 500 then come back and stay at 900. Sometimes it will drop back down to 750-800 ish but why is this happening? It also happens when I turn on my headlights or turn my a/c on. I also notice my rpms dropping when I brake sometimes (abs engaging?). I'm thinking its a grounded out wire from the things I've read on here but where should I look?

racepar1 · 03-08-2008, 08:43 PM

Have your battery and alternator checked. Your electrical system is too weak to handle any kind of load. It probably it won't be long untill it craps out completely. If they are fine than check your battery cables and make sure that they are tight and do not have any corrosion on them.

Mangudai · 03-08-2008, 08:49 PM

Ahh. Well I purchased a new redtop about 2 weeks ago (was doing this with the old battery as well) so then it must be the wires or alternator. I really hope its not the alternator. I'll take it to get tested tomorrow

Thanks a lot.

racepar1 · 03-08-2008, 08:52 PM

Check the battery cables VERY closely. If there are ANY signs of corrosion or the terminals are loose then buy or make some new ones.

LongGrain · 03-08-2008, 09:23 PM

i think thats normal, my car does the same thing when i remote start it, the parking lights go on and off, and everytime they go on, my idle dips and recovers. its just load on your alternater

clark · 03-08-2008, 09:28 PM

most power steering systems are equipped with a sensor that detects when your rack is at "full lock" and this will tell the ECU to bump up the idle at full lock. look at your high pressure hose, you should see a wire coming out of it. commonly on SR swaps, this is no longer used because of either A. some opt not to use power steering anymore or B. some are too lazy to extend the power steering wire because it's located on the other side of the engine bay because the SR harness is innately RHD.

also you probably see the idle drop when you turn your AC on because the AC clutch puts additional stress on your crank/pulleys. there is also a feature on most cars that will bump up the idle when the AC is on as well. perhaps something could be wrong with that component

if you don't have an engine swap, ignore the part about power steering. but either way, i would inspect that sensor and make sure it is connected and what not.

your brake booster works off vacuum. I'm not sure how you can observe this while you're braking because your RPMs would of course drop while you're braking. but if you're at idle, and you give your brakes a nice press, and your idle drops it like it's hot then there could be a problem with your booster.

EDIT* oh yeah....i wouldn't be alarmed about the headlight thing tho. any car I've ever owned did this. I'm no expert but it's probably due to the additional draw you're putting on your electrical system when you flick them on.

BustedS13 · 03-08-2008, 09:36 PM

check your grounds. and then add a few nice thick grounds. i added several 8 gauge ground wires to various points in the engine bay and it made a noticeable difference.

Mangudai · 03-08-2008, 10:00 PM

Well I started my car up and tried different things to see if it would affect the idle. Turning on the headlights made the idle dip (as well as turning off completely) but I tried it again several times afterwards and it didn't affect it. When I pressed the brake in while I was parked the idle raised very slightly then dropped then when I left off it did the same thing. I connected my faceplate and played a cd and my idle dipped but I tried to replicate it and once again it didn't happen. The a/c is always affects it, though like clark said its to be expected.

Quote:

check your grounds. and then add a few nice thick grounds. i added several 8 gauge ground wires to various points in the engine bay and it made a noticeable difference.

Sorry for my ignorance but does do these look like?

Mangudai · 03-10-2008, 06:38 PM

Went to get the alternator tested today, unfortunately the guy told me its not holding a charge and if I had to drive the car avoid using the a/c, ugh. It sucks but atleast I know what needs to be fixed. Now im off to price a alternator but question, what brand would you recommend?

Thanks

Mangudai · 03-12-2008, 02:01 AM

Are the reman alternators ebay any good? Or should I stick to Denso or Bosch? The ones on ebay are less than half the price but come with a one year warranty so i figure they cant be that bad..

seto_s14 · 03-12-2008, 02:07 AM

i'd say get the bosch at autozone or pepboys or whatever. ebay warranties are whack.

EDz s14 · 03-12-2008, 08:34 PM

Hey, let me know if the alternator fixed the problem. Mine does the same exact thing.

Mangudai · 03-13-2008, 04:27 PM

^ Sure no problem

Quote:

Originally Posted by seto_s14

i'd say get the bosch at autozone or pepboys or whatever. ebay warranties are whack.

Thanks

03-08-2008, 08:37 PM	#1
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	Using anything electrical affecting idle? Say I turn the steering wheel while im parked, the idle will drop down about 150 rpms then raise up about 100-150 rpm. So if im at 750 and turn the steering wheel the idle will drop down to 500 then come back and stay at 900. Sometimes it will drop back down to 750-800 ish but why is this happening? It also happens when I turn on my headlights or turn my a/c on. I also notice my rpms dropping when I brake sometimes (abs engaging?). I'm thinking its a grounded out wire from the things I've read on here but where should I look?

03-08-2008, 09:36 PM	#7
BustedS13 Post Whore! Join Date: Jan 2004 Location: Phoenix AZ Age: 40 Posts: 10,287 Trader Rating: (0) Feedback Score: 0 reviews	check your grounds. and then add a few nice thick grounds. i added several 8 gauge ground wires to various points in the engine bay and it made a noticeable difference. __________________

03-12-2008, 02:07 AM	#11
seto_s14 Zilvia Member Join Date: Apr 2007 Location: 626 Age: 36 Posts: 297 Trader Rating: (3) Feedback Score: 3 reviews	i'd say get the bosch at autozone or pepboys or whatever. ebay warranties are whack. __________________ San Gabriel Car Detailing https://www.ocdshine.com

03-08-2008, 08:43 PM	#2
racepar1 Post Whore! Join Date: Jul 2007 Location: Simi Valley, CA Age: 42 Posts: 9,006 Trader Rating: (106) Rides Gallery: racepar1 Feedback Score: 106 reviews	Have your battery and alternator checked. Your electrical system is too weak to handle any kind of load. It probably it won't be long untill it craps out completely. If they are fine than check your battery cables and make sure that they are tight and do not have any corrosion on them.

03-08-2008, 08:49 PM	#3
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	Ahh. Well I purchased a new redtop about 2 weeks ago (was doing this with the old battery as well) so then it must be the wires or alternator. I really hope its not the alternator. I'll take it to get tested tomorrow Thanks a lot.

03-08-2008, 08:52 PM	#4
racepar1 Post Whore! Join Date: Jul 2007 Location: Simi Valley, CA Age: 42 Posts: 9,006 Trader Rating: (106) Rides Gallery: racepar1 Feedback Score: 106 reviews	Check the battery cables VERY closely. If there are ANY signs of corrosion or the terminals are loose then buy or make some new ones.

03-08-2008, 09:23 PM	#5
LongGrain Post Whore! Join Date: Sep 2006 Location: Midwest Posts: 2,741 Trader Rating: (5) Feedback Score: 5 reviews	i think thats normal, my car does the same thing when i remote start it, the parking lights go on and off, and everytime they go on, my idle dips and recovers. its just load on your alternater

03-08-2008, 09:28 PM	#6
clark Zilvia FREAK! Join Date: Mar 2008 Location: new york Posts: 1,035 Trader Rating: (1) Feedback Score: 1 reviews	most power steering systems are equipped with a sensor that detects when your rack is at "full lock" and this will tell the ECU to bump up the idle at full lock. look at your high pressure hose, you should see a wire coming out of it. commonly on SR swaps, this is no longer used because of either A. some opt not to use power steering anymore or B. some are too lazy to extend the power steering wire because it's located on the other side of the engine bay because the SR harness is innately RHD. also you probably see the idle drop when you turn your AC on because the AC clutch puts additional stress on your crank/pulleys. there is also a feature on most cars that will bump up the idle when the AC is on as well. perhaps something could be wrong with that component if you don't have an engine swap, ignore the part about power steering. but either way, i would inspect that sensor and make sure it is connected and what not. your brake booster works off vacuum. I'm not sure how you can observe this while you're braking because your RPMs would of course drop while you're braking. but if you're at idle, and you give your brakes a nice press, and your idle drops it like it's hot then there could be a problem with your booster. EDIT* oh yeah....i wouldn't be alarmed about the headlight thing tho. any car I've ever owned did this. I'm no expert but it's probably due to the additional draw you're putting on your electrical system when you flick them on.

03-10-2008, 06:38 PM	#9
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	Went to get the alternator tested today, unfortunately the guy told me its not holding a charge and if I had to drive the car avoid using the a/c, ugh. It sucks but atleast I know what needs to be fixed. Now im off to price a alternator but question, what brand would you recommend? Thanks

03-12-2008, 02:01 AM	#10
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	Are the reman alternators ebay any good? Or should I stick to Denso or Bosch? The ones on ebay are less than half the price but come with a one year warranty so i figure they cant be that bad..

03-12-2008, 08:34 PM	#12
EDz s14 Leaky Injector Join Date: Jan 2008 Location: SoCal Age: 35 Posts: 114 Trader Rating: (2) Feedback Score: 2 reviews	Hey, let me know if the alternator fixed the problem. Mine does the same exact thing.