Yummybud924

Whenever it rains or I wash my car the car idles too low and shakes and vibrates more than usually only during idle above 1000 rpm it's fine.


Also whenever I turn on my headlights or heater, or anytying that draws electricity, the idle drops a little and it idles rougher. I suspect my motor mounts are bad again after replacing them last year as it shakes at 950 rpm also.

I have new spark plug wires, new spark plugs, cap and rotor are 2 years old and 15k kms. Vacuum lines were all replaced. fuel injector seals are replaced same with intake manifold gaskets. Idle stabilizer was also replaced and it works (vibrates).


Even when dry and no lights or electrical appliances on it still idles a bit rough until it's reved above 1000 rpm but with lights on or in the rain idle sometimes drops to like 600 rpm


anyone know what this could be? forgot to mention my batter is pretty new also and according to the voltmeter on the dash it's not low on charge.

V2Rocket

sometimes after pressure washing my engine it is hard to start, i figure that some water gets into the sparkplugs or something. just a quick shot of air and it works just fine.

the idle dropping is because of extra power draw. before i put a custom harness on my lights whenever i was driving at night and the engine got hot the lights would dim for a second when the fans switched on.

check your afm/tps/dme relay you might just have a dirty contact or something

Spidey944

Man your car has a lot of issues.... ALL the time. LOL.

Yummybud924

lol well nothing that prevents me from driving it.

right now the only things I know are wrong with it are a power steering rack leak and the vibrations at idle.

I replaced the motor mounts last year and the porsche dealer gave me Mehle motor mounts for 130 each and I found out these are the aftermarket ones sold on pelican for half that price.

Anyways I raised the idle of the car to like 1000 rpm so there are less vibrations but when I turn on my lights now or it's raining the idle drops. i'm scared the excessive engine vibrations will crack my fuel rail or oil pick up tube. I already had a snapped alternator tensioner.


why would electrical draw cause a lower idle? could my alternator not be putting out enough power?


I did clean all my electrical connections. Might have some rusty or corroded ground wires though.

hrsteel

That's what I was thinking. Maybe your alternator is trying to give up and a little moisture is enough to really reduce its efficiency.

You can try starting your car up on a dry day and spray a little water around in different places until it starts acting up. Note: I do not recommend you use the water hose after the engine is hot, or you'll just end up with a really big mess to clean up.

Yummybud924

maybe I should clean the connections to the alternator.

marky522

have the Plug wires been replaced??? Cap and rotor?

Mark

Vjgtrybno1

Throttle position sensor?

Yummybud924

yes like I said cap rotor , wires are all new.


tps could be a problem my tps was sticking and the idle was getting stuck at higher rpms but I cleaned the throttle body and now it's not doing that.


why would the car idle lower when the tps gets wet?

also it seems unlikely that the tps would get soaked when it's raining or after i wash teh car.

Yummybud924

okay I ran the car in the dark after washing it and I noticed the rotor is arcing to the camshaft sprocket.

is this normal? I could see it arcing through the camshaft inspection hole, could see the blue flashes of electricity.

anyone know why it would do this?

Yummybud924

bump

anyone know why my rotor would be arcing to the cam sprocket? I see blue flashes to the sprocket at night.

mynus2

electricity like water will always take the path of least resistance some of my older cars have had similar problems and the culprit was always dirty engine. when the parts get dirt grime but especially grease or oil on them it will cause an arc path

Lizard944

It might just be static electricty discharge given off by the friction of the belt passing over the cam gear sprocket. Might be more noticeable in dry air. I was checking for spark plug wire leaks in the dark on my Explorer and noticed some glowing sparks in one area. When I turned on a flashlight to locate it, it was coming from a tension roller on the serpentine belt.

speedtek

If you have a Bosch cap you may need to scrape the plastic off the copper rotor contacts. also wipe the inside of the cap dry. do not use any type of cleaners. I use a dremel with the wire brush wheel,