Uneven Idle, slow turn signal. Need suggestions.

So the other night is the first time I took the Riv for a good drive since I bought it a few weeks back. Two things happened that concern me a little and would like to resolve.

One, when I come to a stop at a light and sit for awhile the car's idle starts getting erratic. It jolts, skips and whatnot. Sometimes it skips enough to effect the lighting(starts twitching) and I noticed the turn signal slowing down. If I put the car in neutral it goes away. It only happens when I'm stopped and in gear. Possible alternator? Suggestions?

Thanks for any suggestions!

Is the idle getting too low causing the lights to dim? (low rpm will dim everything).

rough idle can be a few things. may want to run seafoam through the booster line and the gas tank. then change out the plugs if they are old.
also could try cleaning the IAC valve and TB by hand (spray cleaner).
finally i would spray down the MAF with maf cleaner to make sure there is no grime on the sensor.
all of these are cheap (seafoam can be a little pricy) PM items anyways for acquiring a "new" car.

VJD2 wrote:

One, when I come to a stop at a light and sit for awhile the car's idle starts getting erratic. It jolts, skips and whatnot. Sometimes it skips enough to effect the lighting(starts twitching) and I noticed the turn signal slowing down. If I put the car in neutral it goes away. It only happens when I'm stopped and in gear. Possible alternator? Suggestions?

Don't forget to rule out the easy stuff for this issue. Mine was similar and it ended up being the battery connections under the back seat. Check the connections and your grounding cable where it connects to the car. If it all looks good, move on from there...

Abaddon wrote:

Is the idle getting too low causing the lights to dim? (low rpm will dim everything).

Sort of. It idles rough for awhile then all of the sudden the lights dim. Almost like something clicked and is drawing current all of a sudden. Weird.

Mr.Riviera wrote:

rough idle can be a few things. may want to run seafoam through the booster line and the gas tank. then change out the plugs if they are old.
also could try cleaning the IAC valve and TB by hand (spray cleaner).
finally i would spray down the MAF with maf cleaner to make sure there is no grime on the sensor.
all of these are cheap (seafoam can be a little pricy) PM items anyways for acquiring a "new" car.

Bought some today. $10 for a little can. Jeeze! But if it does the trick why not, besides I was going to do it anyway to clean everything out.

Karma wrote:

Don't forget to rule out the easy stuff for this issue. Mine was similar and it ended up being the battery connections under the back seat. Check the connections and your grounding cable where it connects to the car. If it all looks good, move on from there...

Ya I'm trying to rule out the simple stuff first. The car got a new battery when I bought it and I checked the connections. They seem pretty tight but might have to check the ground. I'm going to measure the alt. output as well at idle. You never know.

I already replaced the plugs with 104's like everyone suggested also because a pulley is in the near future and I also replaced the spark plug wires so those are ruled out. Although I'd like to get my hands on some performance wires down the road.

Thanks guys.

VJD2 wrote:

Abaddon wrote:

Is the idle getting too low causing the lights to dim? (low rpm will dim everything).

Sort of. It idles rough for awhile then all of the sudden the lights dim. Almost like something clicked and is drawing current all of a sudden. Weird.
Thanks guys.

The alternator won't put out any current at all at startup with very low RPM. I forget exactly what is happening technically in the backround, but once you step on the gas a little and increase RPM the Alternator will start putting out it's rated voltage, and amperage, depending on load.
You can watch it happen if you have a voltmeter hooked up in the cockpit or from under the hood with someone else attempting to start it, first, without stepping on the gas pedal, and then trying to start with a little gas. This all happens if you have a healthy charging system.
As far as checking Battery cables and ground connections, also loosen and remove the nut securing the cables at the underhood connector, BE CAREFUL with the large cable running back to the battery if you haven't disconnected the battery, and use some fine sandpaper or small wire brush (toothbrush size works good for this job and they are cheap enough at the auto parts stores) to clean those ring terminals. While the Alternator cable is disconnected at the underhood terminal block, go ahead and remove the other end at the alternator, clean with sandpaper and reattach and tighten connection very easily. Doesn't require a lot of torque and if you over tighten you can break the terminal inside the alternator. Just so you know, don't over tighten. Also, look for any diameter wires that are either screwed or bolted to the chassis or body and do the same to them. Remove, clean and reinstall. Cleaning ground connections like those can solve a world of different problems on any car.
After having cleaned and checked all connections for tightness you should do a final alternator output test. If you have a proper load tester, Great. If not, just turn on all accessories that you can while watching the voltmeter from under the hood and at the Battery and you can manipulate the throttle to see what the voltage rises to at various RPM's. If it is still very low Volts at idle you now have to determine if it's the Alternator.
Without all the necessary testing equipment it can be very easy to remove the Alternator and bring it one of the larger auto parts store for a bench test if necessary.
Try all these little things as they are good preventive maintenance anyway.

might want to check and see if any of those plug wires, by some chance, came loose.

Albertj

Rickw wrote:

VJD2 wrote:

Abaddon wrote:

Is the idle getting too low causing the lights to dim? (low rpm will dim everything).

Sort of. It idles rough for awhile then all of the sudden the lights dim. Almost like something clicked and is drawing current all of a sudden. Weird.
Thanks guys.

The alternator won't put out any current at all at startup with very low RPM. I forget exactly what is happening technically in the backround, but once you step on the gas a little and increase RPM the Alternator will start putting out it's rated voltage, and amperage, depending on load.
You can watch it happen if you have a voltmeter hooked up in the cockpit or from under the hood with someone else attempting to start it, first, without stepping on the gas pedal, and then trying to start with a little gas. This all happens if you have a healthy charging system.
As far as checking Battery cables and ground connections, also loosen and remove the nut securing the cables at the underhood connector, BE CAREFUL with the large cable running back to the battery if you haven't disconnected the battery, and use some fine sandpaper or small wire brush (toothbrush size works good for this job and they are cheap enough at the auto parts stores) to clean those ring terminals. While the Alternator cable is disconnected at the underhood terminal block, go ahead and remove the other end at the alternator, clean with sandpaper and reattach and tighten connection very easily. Doesn't require a lot of torque and if you over tighten you can break the terminal inside the alternator. Just so you know, don't over tighten. Also, look for any diameter wires that are either screwed or bolted to the chassis or body and do the same to them. Remove, clean and reinstall. Cleaning ground connections like those can solve a world of different problems on any car.
After having cleaned and checked all connections for tightness you should do a final alternator output test. If you have a proper load tester, Great. If not, just turn on all accessories that you can while watching the voltmeter from under the hood and at the Battery and you can manipulate the throttle to see what the voltage rises to at various RPM's. If it is still very low Volts at idle you now have to determine if it's the Alternator.
Without all the necessary testing equipment it can be very easy to remove the Alternator and bring it one of the larger auto parts store for a bench test if necessary.
Try all these little things as they are good preventive maintenance anyway.

albertj wrote:

might want to check and see if any of those plug wires, by some chance, came loose.

Albertj

Thanks for the suggestions. I'll have to do this stuff this week when the freaking rain stops. Hopefully I can find out why this is happening. Its a little annoying.