RPMs take a dive in D

[2True]

OK so my car idles at 800rpm (+ or - 1)and when I put it in D or R it takes an unholy plunge to like 550rpm. Someone tell me that isn't normal...

My Chilton's says it's acceptable but at the lowest of the acceptable scenarios. What could be going on? My tranny runs fine while driving, good fluid level, ignition good, TB good... I just can't figure. The only idea I have is maybe it needs a flush but the fluid is still clear purple-ish.

BTW, for those with the reverse EL gauges, am I even reading the idle correctly? the reason I am asking is because there's "0" and then a blank space and then the lines start at 500rpm, right? My car idles right at the second line on the tach when in D.

I am so damn confused https://www.thegalantcenter.org/style_emoticons/default/wacko.gif someone make sense of this post for me please..

Wes

[BEAST]

Mine does that too. Not quite as much as yours but it still does a little. I have wondered the same thing.

[manybrews]

clean the throttle body.

[2True]

<div class='quotetop'>QUOTE(manybrews)</div><div class='quotemain'>clean the throttle body.</div>

Why would a dirty throttle body cause the RPM to drop in Drive? It idles just fine in P or N, It only drops when in gear.

[BLsGalant97]

Wes, yeah i've been having the same problem too lately...http://clubtgc.org/forum/viewtopic.php?t=6711 ('http://clubtgc.org/forum/viewtopic.php?t=6711')

And thats the way i read the reverse indiglos too...may be they are a little off, but i dont even remember what the factory gauges look like anymore.

[2True]

I don't seem to have any of the electrical issue's your having Brandon.. I have no electric problems what so ever actually. It appears mechanical. I plan on scrubbing my TB out with some cleaner and a damn toothbrush tonight, I'll let ya know what happens :wink:
Last time I did it though, my check engine light came on and my car spuddered for a day or so.. :?

[NRG]

It is suppose to drop when in gear.......All cars do that....But the question is how much.......

[manybrews]

clean the throttle body.

[JiP]

If you have a datalogger you can see what your ECU sees as RPM, I have custom gauges and most people with after market gauge faces don't put the needles in exactly right.

But my galat in P or N runs abou 1100rpm, when I throw it into gear R or D it drops to about 800.

If cleaning your TB dont help, you can adjust the BISS screw on the TB that will easily raise your idle RPM, but its range is only like +-100 or less.

[Nick VR4]

Just went out to car park at work to check mine
P or N = 800 rpms
D = 700

Thats after engine has warmed up

[manybrews]

the car is suppost to run at 750 +- in part/nuetral, and will obviously drop a hair in drive (but eventually get close to 750 again).

if its not doing this, clean the throttle body.

[BLsGalant97]

<div class='quotetop'>QUOTE(manybrews)</div><div class='quotemain'>clean the throttle body.</div>

How exactly do you clean the throttle body??? Is it something i can do by myself?? how hard is it???

[JiP]

Just get some carb spray at autozone or whatever your local autoshop is. It's probably easier to remove the tb from the car to clean the inside area which on my car was the only dirty side. Not only that Ive seen peoples TB so crusted up that there was a big improvment in idle and throttle response after a scrubbing, but my galant came with egr block off plate what is that FED emmisions ? so my TB is always pretty clean.