Civic speed and rpm issue

Just fit a exchange unit ,,the electronic regulator is faulty end of story .Plus voltage drain could be a diode packed up ,just fit a exchange unit ,

I would consider changing the vehicle speed sensor. When they go bad, they can really throw out a lot of bad data to the computer, resulting in unexpected behavior like you're experiencing. They're only around $20-$25. I hope this helps! :)

Check that you have not reached the engine rpm limiter and the CPU is going into limp home mode. Run fault codes as the engine light comes on it may tell you the problem

the power used by the accesories is causing the increase in RPM on idle but when its doing it at anything over 1000 rpm then its a fault in the sensor that reading the idle which can be either the air flow speed or the RPM gauge ,now any thing further iam at a loss as we do not have this model here in spain so i havent worked on one and i have no diea as to what system is being used ,you would need dealer software to check the ECU computer and see whats happening not a fault code :Sorry i cannot be of any help

rpms do increase when you push the pedal to go faster....but then if it is an automatic tranny, it may be slipping thus rpms are fast but speed doesn't match rpms. luck to you

could be fluid level but probably not

check automatic idle speed motor if equipped.

check for vacuum leak

ram1105: when you shift out of overdrive the transmission actually is in a 1-1 ratio with the input shaft of the transmission. Meaning for every revolution of the input shaft, the driveshaft turns the same number. When you shift to overdrive, the ratio changes allowing the engine speed and input shaft speed to slow down while the number of RPM's increases on the driveshaft shaft. The change is not too significant. Usually about a 500 RPM change is normal. You may have a problem with slippage within the transmission overdrive unit.
It may be advantageous to have the transmission pan dropped and it's contents inspected for debris. Older Nissan Automatics were not known for failures. The 3N71B was bullet proof and the 4N series which was just an overdrive added to it, were very reliable.
My son, best friend and I road race Nissan 300Z's. There are a variety of gear ratios for the R200 differential. The 3:70 is the tallest factory setup on a production Z, which would give you the lowest RPM at a higher speed. Outside of that, the tallest tires you can run on the car will also lower the RPM's.Don't forget there is always a trade-off. When you make a gear and change to taller gears, the car is going to feel more sluggish off the line. It will take longer to attain 0-60 unless you increase HP & Torque. I can help you there if you want to know how to do it.

dude its normal for first start or cold start that the idle is ok but it must high than normal... its normal because the engine is warming up it self... when it gets warm, the idle speed will return normal idle... your engine is 1200cc, it has not much HP for a great load... and i know its a carburatored engine and its an old engine, your head lyt and a/c fan and aux fan and all the electrical system on your car, uses the HP of you engine and its a lot of load to the alternator driven by the engine to generate an electricity they need and thats why the engine rpm speed lowering down to dead and its shake. thats why when you use your lyts or all electrical, you engine is weakening... the best remede is adjusting you idle speed... its located behind the carburator.. its a small black knob.. just make a twist each eighter way and you'll find out if your idle rpm speed ts incresing or decresing.. just increase it and try opening your lyts and other electrical, if its still shaking then adjust it a little more