rpm prob

when the car is at idle, it will sit at 1000rpms and the jump to 1500rpm and up and down and up and down like i am reving it up constantly....
what is my prob guys...i got a 1990 dx

Vacuum leak is most likely. could be a few different problems but that is a good place to start, check all of the lines on the manifold, especially your map sensor.
Which should be mounted to the firewall with a hose running from the mani. See if any of those have breaks in them. A trick some people use is to spray the hoses with a little water, and if the idle problem stops for a second you know you've found the hose because the hole will be plugged momentarily by the water it sucks in. Ive also heard this method is a joke..but its definitely worth a shot.

will try this thanx

when the car is at idle, it will sit at 1000rpms and the jump to 1500rpm and up and down and up and down like i am reving it up constantly....
what is my prob guys...i got a 1990 dx

Also check your IACV and try adjusting your idle while your at it.

i had to adjust my tps sensor to fix the problem when my car was doing that.