Power loss, bouncing RPMs on 2000 Civic
 

I have a 2000 Civic, D16Y7. There are several symptoms, and I'm having a hard time pinpointing the issue. If I accelerate normally, say, when getting on the highway, I have no issues. Everything shifts normally, and there is no hesitation. However, if I am in traffic, the car has trouble shifting between 1st and 2nd gear. This only happens, though, when I'm going between 15-30 mph. Not only can you hear the car hesitate, but the tachometer bounces between 1000-2000 RPM. If I accelerate to a faster speed, I have no issue.

The other thing that the car loses power drastically when I let off the gas. At higher mph, it's not so bad. But again, b/t 15-30 mph, if I let off the gas, the RPM plummet, the car slows way down, and then it'll correct itself. It's similar to the drop off you'd experience in a manual trans.

A couple days ago, at each stop light, the engine would bog down, to the point where it nearly quit, but it would always pull back up. Other than this experience, I've had no issue with idle or start up. RPMs are consistent there.

My gas mileage is way, way down. I'm down from ~320 miles per tank to ~260.

I recently replaced the TPS and fuel filter. The distributor cap and rotor are fine.

No codes have been thrown.

Re: Power loss, bouncing RPMs on 2000 Civic
 

http://www.ehow.com/how_7716813_clea...vic-ferio.html
Giving the throttle body a cleaning may help your problem, unless it is sensor related.

Re: Power loss, bouncing RPMs on 2000 Civic
 

This is an update for this post.

Following this post, the car threw a CEL for the IAC valve, which I replaced with a used OEM (Denso) part. While replacing the part, I cleaned the throttle body really, really well. While this solved part of the issue, it still didn't solve the bouncing RPM issue.

I tested the MAP sensor, also, and it was functional.

Ultimately I replaced the entire throttle body and this finally solved the problem.

From what I can gather, replacing the TPS sensor with an aftermarket part may have made the problem worse. In this case, replacing the entire TB with original MAP and TPS sensors worked. I know in many posts here, people have had success with an aftermarket TPS, but here's my argument:

I spent $30 for the aftermarket TPS and had remaining issues for months.

I spent $55 for a used TB on ebay with the original TPS, and this solved the problems I listed in the original post. The IAC valve was $50, also.

The repair cost a total of $100, but it seems that, if you have issues with the TPS, you should replace the entire TB.

As a side note, it took less time to install the TB than it did to remove the old TPS and install and calibrate the new one. Just replace the throttle body!

Re: Power loss, bouncing RPMs on 2000 Civic
 

bouncing RPM usually is because of air in the coolant system, causing the IACV the open and close. You need to bleed out the system, sometimes this takes quite awhile.