Hey, first post but I've been using this site for troubleshooting for a while. I have a 1995 accord LX 4cyl 201,000 miles, and the most recent problem its having is a rise of power and drop at speed. When I'm going around 45mph or more the RPM will drop about 200 and then rise up again. If this happens at low speeds its to small for me to notice. Any ideas?

 

Is RPM fluctuating up/down at a steady speeds? Is D4 light flashing?

If yes, the torque converter lockup may be going off/on. This will cause an rpm change of about that value. See DIY section and check for Trans Control Unit codes using same procedures as Check Engine Codes, but watch the D4 light flashes and count them to get the code. Some codes don't cause the D4 to flash so check even if no D4 flashing.

It could also be an engine fuel control issue. Does engine start and run smooth, accelerate smoothly? Is engine missing?

More details necessary to help.

good luck

 

I took it on the highway today and it seems to be a range that causes the fluctuations. once i get past a certain speed/rpm it runs solid. so it seems to be a bad range. I was wondering if the spark plug wires could be part of the problem. I put new ones in a little while ago and one of the wires is longer than the older ones were. with how often they fire a second I was thinking that the current pulse could be off because of the different length

oh and my car starts and idles fine. very smooth. it just seems to be that range 40-65 mph, when it gets pushed to increase the speed in that range the power drops. ill check to see if there are any codes. no lights are on from it

 

EGR manifold, ports, and EGR valve may need cleaning. See DIY section for guidance on this procedure "HOW TO........Cleaning EGR Ports ( Hondadude )"

good luck

 

Cleaned the ports out. there was a lot of carbon in there. but now my car idles extremely low. just barely above the first line. It seems to run smooth even at that rpm but it worries me. Is it just some of the carbon working its way out of the system? im going to get some fuel injector cleaner and next time i fill up put in the highest grade gas in hopes to burn it out.

by the way I found this. it doesn't show taking off the fuel rail which needs to be done. but its still pretty good in case someone reading this needs some instruction. its good for 90-97 accords.
http://www.tegger.com/hondafaq/misc/t2t013.pdf

 

Try setting your base idle now that you've cleaned out the EGR.

And remember, the tachometer scale doesn't actually start at zero.
The first small line (real close to zero) is 500. Then the first major line is 1000.

 

You should also clean the throttle plate and Idle Air Control Valve (IACV). These control idle speed and may be clogged w/ gunk.

good luck