I have a 97 Eclipse RS automatic , my car idles at around 1300 -2100rpms when in park "even as high as 2500 with the air conditioning on , when i change from "park to drive it feels super rough on my transmision i have to turn it to drive with my air conditioning off so it doesn't feel so rough, anyways another huge problem is when im stoping or moving at realy slow speed "0 -10mph and i have my foot on the brakes the car will buck realy hard , it will not buck when im cruising or when the car is totaly at a stop but anywhere from around 20mph or less when im stoping it will buck realy hard , recently after the car "bucks" it turns off , the weird thing is when the car bucks the rpms are around 1000rpm and it just will buck and shut off. When i am cruising if i let off the gas the car will not slow down also , the idle has been set lower and i have reset my battery and the problem keeps coming back. Do you think a vacuum leak is causing all these problems ? bad egr ? bad sensor ? Help please .


Sorry for the double post , i have not received responses on the Eclipse section

 

^ Weird thing i forgot to mention is that the problem happens sometimes , when i use the car more , i went two days without driving my car and it ran and idle'd fine after 2 days of not beeing driven and it didn't buck rpms where at 900 on park and pretty steady. Also reseting the battery seems to help but then eventualy it goes back to the same problem after a day or two.[&:]

 

with an rs you have the 420a not the 4g63t. first your idle can be fixed by moving the cable on the intake manifold. the 4g63t has a biss screw but not 420a. as for your "bucking" problem sounds like a bad speed sensor. there are two different setups. first is a single sensor that bolts on (10mm) on the rear of the tranny under the battery area. the other has an input and output sensor on the front of the tranny. IMPORTANT!!!!! replace the speed sensor before messing with the idle. a bad speed sensor will make you car idle funny and shift had or not at all. replace the sensor and let me know if that fixed the problem.

First 97 Talon 420a, Second 95 Eclipse 420a, THIRD 95 4g63t GSX AWD 16G TURBO

 

Ok i checked and unpluged some sensors and got check engine lights , reset the battery , went to auto zone ran a code test after the battery is reset no check engine light is lit , and no codes on the machine. Car moves foward when i turn the ac on , sometimes it doesn't
do it as bad im thinking theres a vacuum leak near the egr valve perhaps , and the "bucking problem" only happens when im hiting the brakes , mostly when i double tap the brakes , right before the car fully stops it will buck hard and the rpms are around 1100 . The car did not turn off when it bucked a few times like the other day ,. The other day right after it bucked it would shut off, but it's not turning off now.

 

ther 420A DOES have a biss screw, I know, I adjusted mine. Also, could it be the torque converter clutch solonoid?

 

ther 420A DOES have a biss screw, I know, I adjusted mine. Also, could it be the torque converter clutch solonoid?

the 420a DOES NOT have a biss screw. if so where?????? not on the intake. or anywhere else. show me a picture.

 

Well i took it to the shop i usualy take it to they test drove it and they said it seems like "a bad torque converter selonoid and mayb some circuit problem within the air conditioning system" so my car needs to go to a transmision shop and it doesn't look cheap , . Thanks for the help magnet and hossier.

 

Back from the Transmission shop , they put a Master rebuilt kit on my transmission , replaced some seals and torque conveter and clutch etc $1600 dollars , and now driving the car back from the shop im stoping at a light and start pushing the brakes down slowly and right before the car comes to a stop it does the same thing ![:@] It bucks and the idle shoots a bit high like 200 rpms higher then goes down after 20 secs ... im starting to think its got something to do with the air conditioner or fan motors but even with it off it does it its just with the ac off it's less noticeable , mayb it's something electronic i dont know but its afecting the car everytime i stop the car you can feel it shake and buck. No check engine light all sensors are checking fine[&:]

 

its on my TB, just seen that you replied to this post and will get a pic up for you to see within a day

 

there is no adjustment of any kind on the 420a throttle body.
do not ever touch anything on it.