85 GS
RB Intake Housing
RB Streetport Exhaust

With the housing issue, the idle compensator tube is left dangling open... Should I plug the idle compensator at all times? When I don't the RPMs will drop slightly and the idle will be a little rougher. Should I do anything to the other tubes that are left open?

Another thing I noticed was that when I turn on my head-lights my RPM drops by about 200... That's not right! Could my alternator be dying?

Thanx...

 

I just read about a valve sensor thing that adjusts the idle speed whenever you turn on an accessory such as air conditioning or defroester or something...check in the haynes manual around the idle speed section i think thats where i saw it. But i know theres a valve or sensor somewhere that contorls the idle for accessories...

~T.J.

 

Hmmm... the only thing I have changed is that I have plugged the idle compensator tube... I'll try tomorrow (it's late right now) with it un-plugged.

 

this is the only idle compensator i could find......http://pittdp.homestead.com/underhood.html

 

What about the alternator?

 

If you are worried abou the alternator I would get it checked for free by one of those auto parts stores. I never heard the idle dropping cause of a weak alternator.

Good luck

I would plug all the tubes you have unattached on the engine.

 

Yea, I thought the idle dropping was WEIRD!

 

I have heard an engine/alternator change in sound when a load was put on the electrical system. But I dont remember the RPM being affected.

 

my rpms drop when the headlights come on too. I added 2 grounds, 1 to the engine block, the other to the body, still does it. My guages are also affected by electrical load. The really strange part is that my 12" sub can thumb hard enough to massage your kidneys and it doesnt affect a single guage or the rpms. What the heck is going on?

 

My gauges also drop with electrical load. Also, when i try to lower both windows, they stop to a crawl, but they do fine when i only operate one at a time.

 

All of my first gens factory ground runs from the battery to the strut tower to the engine block. You can do very little to better this. but more will not hurt anything.

maybe ground the individual components better.?

Test the alternator?

 

the guages dont worry me so much but the idle drops with electrical load and i feel a slight decrease in power. I got my alternator from a junkyard. I called before i wewnt to make sure they had one, and the guy had it at the desk so i didnt see what it came off of. He said it was an '84 but i had do put washers on the bolt to get it to mount correctly so i think it may be a TII alternator. Any other ways to distinguish? I will get my alternator tested but i dont think that is it. My sub can thump my brains out with no affect on anything but my hearing. Fullsmoke I'll tell you what i did if i ever fix it.

 

i believe that the output is about 14v with the engine running, have u checked the voltage with a volt/ohm meter at the battery while running...

 

Thanx Neanderthol...

But I've discovered another problem. When I press the brake, my RPMs drop too!!! They drop about 100~200, and there is a change in the sound of the engine--like it is under load... Is all this happening because i plugged the idle compensator tube? I took it out and didn't see much improvement... Maybe I need to un-plug it and drive it around for awhile. I'll try to test the alternator and un-plug the tube...

 

same here man

 

My RX-7 does all this, but so does my mom's Nissan AXXESS ('95 Minivan. If you turn on the defroster the idle drops, turn the headlights on and the idle drops. Put your foot on the brake in park, Idle drops. It's normal, I'm assuming ('cause her van only has 53,000 KM on it... I don't think anything would be wrong with it...

I think the foot on brake part is just because the vacuum boost is stealing a bit of the air pressure from the intake manifold, slowing down the air/fuel mixture, but I don't know why idle drops with all the accessories...

I personally wouldn't worry about it unless it's a REALLY noticeable drop in idle speed (like 500+ RPM) It's not that big of a deal. Not like anyone would notice anyways.

Jeff

 

My seven also does all of the above. I think it has to do with the type of altenator that we have (the maximum amp out-put). You know it not like a Suburban's, that can power a small neighberhood at idle. I'll bet that the amp output of the alt. is just about equal to the maximum load that the electrical system can apply. So there is just not a lot of power to go around.

When I have the heater, head lights, brake and stereo running at idle my voltmeter reads just barely above 12v. Just FYI.

Ryan

 

OK... I tried this and that... Nothing seemed to fix the problems... Maybe my 7 is telling me it's getting old?
Anyway--what's the function of the idle compensator? It closes at temps less than 149F and opens if greater... What will this affect?
Close to the idle compensator in the stock filter housing is a larger tube--what does that do?
And finally... I also can't figure out what the other small tube on the filter housing, right behind the alternator, does!

I'm probably gonna plug up those tubes since they are not being used... I just need to know if plugging them will affect my engine's performance...

 

The vacuum from the brake booster probably causes that. Do you have a firm brake pedal?

 

Yes, I recently replaced my rear brake setup and also bled the whole system... The brake pedal is nicely firm...

 

I have a question...

Whenever I'm in nuetral and I'm coasting to a stop sign/light... If I let off the brake completely then I hear this little clank noise that sounds like it's coming from either right under me, or right in front of me.

I'm assuming that this is bad, but it doesn't sound real loud or anything (although I can hear it over the engine and music)

And it happens maybe 1 to 2 seconds AFTER i've let off the brake. Is my car needing repair or is it just something that's a little loose?

 

Wattz: Check your springs in the rear drums (if you have them)... Maybe your power braking assist? I don't know what else to look for...

Anyway... You gurus better answer my questions

 

I'll look at the thing next time I go to Huntsville. Sound fair? I do much better diagnosing in person than on the computer.

 

lol... that would be great
I could borrow my friend's digital camera... I only have a stupid web cam that is kept on a leash...

 

I'm supposed to be going up there to take my gf to see her parents, I usually wind up doing other stuff. Last time, Fire85GSLSE brought me a 12A while I was in HSV