1994 Integra: Strange RPM Behavior (Part 2)

I've had this problem for about a year now. In fact, I had a thread about it at one point here: http://groups.google.com/group/alt.autos.honda/browse_frm/thread/da3b28dad786d5db/37db382debfb1365?lnk=gst&q 94+acura+integra+ls+rpm+behavior#37db382debfb1365
I have about 185k on the car now. Since that time I've had the transmission fluid changed. My mechanic seems to think it may have something to do with the torque converter. The problem is about the same and doesn't seem to be any better or worse, just somewhate annoying. Here is the original message I posted last year (see the link above for the original replies):
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I have a 1994 Acura Integra LS automatic with about 175k miles. I've noticed that something occurs when I'm cruising in the higher speeds. When I'm going about 70mph the RPMs are roughly 3000. When I hit the gas to speed up to 75 or so, the RPMs sometimes (not always) *decrease* by around 200 RPMs . Then it will jump back up to the correct higher RPM a few seconds later, especially if I release the gas slightly. Please note that I'm not hitting the gas hard enough for the transmission to gear down when this happens. At first I thought that it was just the RPM gauge behaving strangely. But, after doing this a number of times, I can actually feel the engine losing the PMs ever so slightly. I can't seem to recreate this issue in lower speeds, however.
Any ideas what could be causing this and how to possibly fix it?
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arock wrote:

http://groups.google.com/group/alt.autos.honda/browse_frm/thread/da3b28dad786d5db/37db382debfb1365?lnk=gst&q 94+acura+integra+ls+rpm+behavior#37db382debfb1365
it's mechanically impossible for the revs to drop while the speed increases - unless the lockup clutch is disengaged, you're going down a hill and you take your foot off the gas. if the revs drop when you increase gas, you likely have a "flat spot" caused by something like bad ignition or blocked egr, but that would be accompanied by a decrease in speed also.
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arock wrote:

http://groups.google.com/group/alt.autos.honda/browse_frm/thread/da3b28dad786d5db/37db382debfb1365?lnk=gst&q 94+acura+integra+ls+rpm+behavior#37db382debfb1365
Hi, How old is the fuel filter? EGR, ignition parts(wires, plugs)?
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The fuel filter might be just a couple of years old and the other parts are in pretty good shape I think. I would imagine if it was any of those parts the car would run badly no matter what the speed, though. My problem only occurs at higher speeds. Otherwise, the car runs great. Thanks...
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arock wrote:

did you check the items i listed - or does "otherwise it runs great" mean you don't have to do that? i mean, usenet means you stay inside where it's warm, but it doesn't fix your car.
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jim beam- I'll be sure to bring those items up you mentioned with my mechanic when I bring it in. I appreciate you taking the time to look into this for me.
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The engines rpm drops by about 200 - 300 rpm when the torque converter lockup engages (load on the engine increases) and jumps up when the TC lockup disengages (trans operates in limited slipping mode)
i've had no experience with Acuras, but in Hondas, the lockup should occurs at about 50-55 mph on moderate throttle and should only disengage when you hit the brakes, or go up a steep hill, or get off the gas pedal (takes a moment), or pound hard on the gas pedal (immediately)
If the TC lockup engages and disengages at the slightest change of throttle or the vehicle's speed, or for no apparent reason at all when cruising, then incorrect throttle valve cable (aka kick down cable) adjustment is most likely the culprit. i'm thinking your cable is loose (too much free play), if it is, tighten it up!! Dont continue to drive your car in this condition or the TC will fail!!!!
i've learned that in newer AT, the lockup mechanism works at lower gears too, but i'm sure none of 1994 vehicles has it, that's why you dont see sudden drops and jumps on the tach at slower speed
oh and make sure the fluid is not burnt and filled at the correct level
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I will definitely have my mechanic look at the throttle valve cable, too. Thanks for your help. I appreciate it.
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