VIBRATIONS, HIGH IDLE, ROUGH 3rd->2nd DOWNSHIFT & ZAP

1999 Mitsu Galant ES (all stock)
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-At startup in park/neutral, it idles at 1500rpms
-At idle in drive w/brake pressed, my steering wheel vibrates...
-when moving, it's smoooth like butter...

-When I'm driving at the 25mph mark and let go of the gas, it kinda jerks. Not bad but I can feel it. A definate downshift. High/Mid pitch tone (3rd) then shifts to (2nd) low rumble tone.

-Also, When I step out of my car and touch the metal frame, I get ZAPPED!!! BIG TIME!!! Bad ground cable? Tires?

http://www.clubtgc.org/forum/viewtopic.php?t=6304
To screw or not to screw?

I've cleaned my throttle body and my entire plastic intake, replaced air filter, flushed transmission w/mitsu ATF, replaced tranny filter, coolant, oil, changed spark plugs, PCV valve, & new battery.

Any ideas?

-Mike.

You might want to try resetting your PCM just for the heck of it. As stated in so many posts, don't mess with the idle adjustment screw. To reset the PCM, remove your negative battery cable for 15-20 minutes, then replace it. Make sure you have the security code for your radio handy, because you'll likely need to re-enter that.

Chip

<div class='quotetop'>QUOTE(clone2020)</div><div class='quotemain'>1999 Mitsu Galant ES (all stock)
-------------------------------------
-At idle in drive, my steering wheel vibrates
-At idle in park/neutral, it's fine...
-when moving, it's smoooth like butter...
-It varies in idle speed: 750-1100rpms

-When I'm driving at the 25mph mark and let go of the gas, it kinda jerks. Not bad but I can feel it. A definate downshift. High/Mid pitch tone (3rd) then shifts to (2nd) low rumble tone.

http://www.clubtgc.org/forum/viewtopic.php?t=6304
To screw or not to screw?

I've cleaned my throttle body and my entire plastic intake, replaced air filter, flushed transmission w/mitsu ATF, replaced tranny filter, coolant, oil, changed spark plugs, PCV valve, & new battery.

Any ideas?</div>


I have the exact same problem.
Wonder whats going on.
BTW I've also done:
-clean TB
-air filter
-tranny service
-plugs

This could be a cold weather/ bad thermostat issue. Does your temp needle ride below center? Your car might not be getting out of cold engine mode. Is your gas mileage crappy? You shouldn't be idling much over 800. Did you do the throttle body cable mod? May be too tight

<div class='quotetop'>QUOTE(Gilhuly)</div><div class='quotemain'>This could be a cold weather/ bad thermostat issue. Â*Does your temp needle ride below center? Â*Your car might not be getting out of cold engine mode. Â*Is your gas mileage crappy? Â*You shouldn't be idling much over 800. Â*Did you do the throttle body cable mod? Â*May be too tight</div>

YEAH!!! It DOES ride below the center mark!!! AND my gas mileage is CRAPPY!!!

I did not modify the TB cable.

Great idea!!! I'll replace the thermostat.

Should the temp needle be exactly at the middle/center mark?

<div class='quotetop'>QUOTE(Fishboy55)</div><div class='quotemain'>You might want to try resetting your PCM just for the heck of it. As stated in so many posts, don't mess with the idle adjustment screw. To reset the PCM, remove your negative battery cable for 15-20 minutes, then replace it. Make sure you have the security code for your radio handy, because you'll likely need to re-enter that.

Chip</div>

The battery already got reset when I purchased a new battery. It took about 20-30 starts for it to relearn everything.

<div class='quotetop'>QUOTE(Gilhuly)</div><div class='quotemain'>This could be a cold weather/ bad thermostat issue. Â*Does your temp needle ride below center? Â*Your car might not be getting out of cold engine mode. Â*Is your gas mileage crappy? Â*You shouldn't be idling much over 800. Â*Did you do the throttle body cable mod? Â*May be too tight</div>
I did the TB coolant bypass. I wonder if that's why my gas mileage is crappy too. Guess I'll switch it back this weekend. Thanks!!

Chip

<div class='quotetop'>QUOTE(Fishboy55)</div><div class='quotemain'><div class='quotetop'>QUOTE(Gilhuly)</div><div class='quotemain'>This could be a cold weather/ bad thermostat issue. Â*Does your temp needle ride below center? Â*Your car might not be getting out of cold engine mode. Â*Is your gas mileage crappy? Â*You shouldn't be idling much over 800. Â*Did you do the throttle body cable mod? Â*May be too tight</div>
I did the TB coolant bypass. I wonder if that's why my gas mileage is crappy too. Guess I'll switch it back this weekend. Thanks!!

Chip</div>

What's the TB coolant bypass?

Also, my front rotors made horrid sqeeking noises. I guess this is common with mitsu stock rotors? I replaced the pads with no change. I haven't had time to replace the rotors with new cross-drilled brembos so I just took some fine grit sandpaper and lightly sanded them. So far, no more sqeeking.

-Mike.

There's a coolant line that runs through your Throttle Body to keep it from freezing in the winter. The bypass just takes that line off and routes the coolant straight back to the block. It will keep your TB cooler which means the airt going in is more dense, but that may be why my gas mileage went to shit after it got colder outside. Maybe my car is running in cold engine mode all the time. It's easy to back it off, just a couple hose clamps, so I'll do that tomorrow.

Chip

<div class='quotetop'>QUOTE(Fishboy55)</div><div class='quotemain'>There's a coolant line that runs through your Throttle Body to keep it from freezing in the winter. The bypass just takes that line off and routes the coolant straight back to the block. It will keep your TB cooler which means the airt going in is more dense, but that may be why my gas mileage went to shit after it got colder outside. Maybe my car is running in cold engine mode all the time. It's easy to back it off, just a couple hose clamps, so I'll do that tomorrow.

Chip</div>
actually, it has nothing to do with that. its there for cold idle speed up, and thats it.

<div class='quotetop'>QUOTE(manybrews)</div><div class='quotemain'><div class='quotetop'>QUOTE(Fishboy55)</div><div class='quotemain'>There's a coolant line that runs through your Throttle Body to keep it from freezing in the winter. The bypass just takes that line off and routes the coolant straight back to the block. It will keep your TB cooler which means the airt going in is more dense, but that may be why my gas mileage went to shit after it got colder outside. Maybe my car is running in cold engine mode all the time. It's easy to back it off, just a couple hose clamps, so I'll do that tomorrow.

Chip</div>
actually, it has nothing to do with that. its there for cold idle speed up, and thats it.</div>

Hey Manybrews,

So, what should I do about my high idle, vibration, & downshift problems? Someone recommended replacing the thermostat. Do you think it's a good idea?

-Mike.

And a cold throttle body would not make your intake air colder. The air passign through the tb passes too fast for it to be cooled by a cold tb. So basically your doing nothing performance wise at all.

<div class='quotetop'>QUOTE(JiP)</div><div class='quotemain'>And a cold throttle body would not make your intake air colder. Â*The air passign through the tb passes too fast for it to be cooled by a cold tb. Â*So basically your doing nothing performance wise at all.</div>
So if that's true, then removing the coolant hose from the TB to keep it cooler in the first place is a waste of time. Am I understanding that correctly?

Chip

I changed the thermostat today. No change. Do I have to start taking apart the engine now?

SYMPTOMS
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-rough idle (750-1000)
-vibrations in the steering wheel
-rough 3rd->2nd downshift
-static electricity buildup when driving (When I turn off the engine, step out of the car and touch the door I get ZAPPED!)

...any more ideas?

-Mike.

From what I can gather...you have all the symptons of my car when it was stock so it might just be that way from the factory. The zapping is normal...the Galant is really nasty about that unless you have leather seats.

<div class='quotetop'>QUOTE</div><div class='quotemain'>So if that's true, then removing the coolant hose from the TB to keep it cooler in the first place is a waste of time. Am I understanding that correctly? Â*
</div>

Yes. Its pretty much basic highschool physics. Unless your cooling your TB to like -20 degrees, your not going to be chaning the air temp passing through. Same arguement some poeple have with plastic or metal intake pipes, some people will say well metal conducts heat and will make your air hot. No it wont, the air flows through it too fast to be affected. You want cold air, put your filter pointing out of the front of your bumper so its in the air strea, hence the name Cold Air Intake. https://www.thegalantcenter.org/styl...ault/laugh.gif https://www.thegalantcenter.org/styl...lt/biggrin.gif

<div class='quotetop'>QUOTE(Rallifan)</div><div class='quotemain'>From what I can gather...you have all the symptons of my car when it was stock so it might just be that way from the factory. The zapping is normal...the Galant is really nasty about that unless you have leather seats.</div>

So, what did you modify to get the idle, vibrations , & 3rd->2nd downshift back to normal?

-Mike.

Have you owned the car since new? That idle speed is just too high. I'd loosen the Throttle body cable just to see if you are truly running at idle.

<div class='quotetop'>QUOTE(Gilhuly)</div><div class='quotemain'>Have you owned the car since new? Â*That idle speed is just too high. Â*I'd loosen Â*the Throttle body cable just to see if you are truly running at idle.</div>

I am the second owner. How do I know if the TB has been messed with?

-Mike.