hi, i ran into this problem yesterday as I was backing out of my friend's driveway. The car is a 1990 Accord LX with approx 130k miles, an automatic transmission, and has been serviced regularly.

As the car was in reverse, i noticed on the tachometer that the revs were not going past 500 rpm when usually, when i drive it, it reverses at around 500rpm and when i step on the gas, usually shoots up to 1500 rpm or so. This is when the shuddering started, the car was jerking, almost like a car would jerk before it stalls out but it didn't stall. I could see the tachometer going crazy around the 0 rpm mark, bouncing up and down from around there. When I set the car back into park and took my foot off the break, everything idled as normal, but when I press the break, the car's rpm will drop and it will start to shudder and buck.

This also happens in drive. In traffic, when the car is stopped, the car bucks as the RPM dips below 1000 and sometimes even below 2000. And when I try to push the accelerator in first gear, the car bucks and shudders all the way until it reaches 2000RPM, then everything appears to be fine as the transmission shifts from gear to gear until fourth gear. At this point, the car seems to lose power, the acceleration drops dramatically and it takes forever to get from 40MPH to 60MPH, when usually it accelerates pretty quickly.

Alright, that's about all I know about what's up with my car and I'm hoping that you guys can help me out about diagnosing the problem. If there's any information I'm missing, please post and tell me what I need to show. Thanks!

Stvwndr219

 

anybody? please help, this is my daily driver and I just took it out and the entire shuddering thing happened again. thanks.

 

Well, until i read the part about this happening when going 40-60 I was pretty sure I knew what it was... disregaurding that statement.. here's what I think...

Could be your idle air control valve going bad...
Could be that your throttle body is dirty and needs to be cleaned...
Also, check your battery connection... make sure the connection is tight.

hope this helps

 

the idling seems to be doing fine except that it skips around in the ~500 rpm range. thanks for the response, we are currently checking the spark plugs and engine mounts. Do you have any links to how to clean the throttle body? thanks again!

Stvwndr219