Hello felow hondatechers, I have a weird issue that I hope somebody can sovle.
When I am driving and I am on the throttle my volt meter that I installed goes down to 12 volts and when I let off the throttle say to coast in neutral or so,ething it goes back up to 14v. I tested the car with the multimeter and when its off I get 12.6 and when on I get 14.1. The only time it goes down to 12 is when im driving the car and stop at a light or sign. I noticed that when its at 12 on the voltmeter the idle is very poor at about 200rpms. Sometimes the car will go back up to 14 when stopped and the idle will go back to about 700rpms which is where I want it. This tells me its an alternator problem but that still doesnt explain why I loose volts while on the throttle. Shouldn't the alternator be charging faster?

 

Anybody?

 

Clean your IACV and learn how to use google or search option on this thread. Even on the first page, there's a lot of threads about idle issue.

 

so, wait you want there to be more volts when the system is underload? (i.e. when you give it throttle?)

 

I did clean my iacv and searched many of times. Im trying to figure out why when im at a stop im idleing at 200 rpms when im at 12v. I always thought that while the car was on Your always supossed to be at 14v.

 

Alternator is just like power generator. If you turn fast, it will produce more voltage. If you turn slow, it'll produce less. It is voltage regulated at fixed 14 volts highest and less. So, at 500 RPM or less, it will produce 12 V or less and > 500 RPM, it will produce more voltage.

Also, how can your car go to 200 RPM? The first bar after 0 is 500 RPM and it's really close to 0.

 

Im morely confused on why it jumps back and forth and when I stop im at 12v instead of 14.

 

Simple physics dude. Don't worry about it unless you see less than 10V @ 500 RPM or more.

 

Thats what I meant sorry. It shakes really bad and feels like its going to stall but doesnt. I rev the engine to like 4 grand at a stop light and it still stays on 12v and doesnt move a bit. I know the more rpms you give it it charges faster right?
Also why would it be at 12v under throttle should it be charging under throttle?

 

Remember that battery is 12 V. Alternator produce 14 V under no load. Maybe your battery is somewhat old and it's probably producing 10 V or 11 V. Therefore, even though alternator is producing 14 V, when it's charging lesser voltage battery it will have a voltage match. 14 V have to come down and 10 V or 11 V whatever your battery has have to come up to the steady voltage. Also, your battery could be reading 12 V but it probably produce less power now. So, under load, it may not produce full 12 V potential.

 

But less than 500 RPM, clean your vacuum system. Google or search on this forums.

 

If you've already cleaned the IACV and the idle speed is still low, then try replacing the PCV valve and adjusting the idle speed (See FAQs sticky for proper procedure).

Any CEL coeds?

Does the charging system light (battery symbol in cluster) turn on while you are driving?

 

No cels and the battery light does not come on. Ive replaced the iacv and reset my ecu. Thanks for the heads up on the pcv valve though. Im going to look into that for sure. Would you recomend reseting the ecu after ive installed a new pcv valve?

 

Yes, after replacing the valve (and adjusting the idle speed if necessary).

 

Awesome, thank you sir!

 

I replaced the pcv and reset my ecu and adjusted the idle. It seems to be running a bit happier. Thanks Ron!