stumble on 95 AT only in manual shift mode

[anomaly]

kk, 95 AT with 81k on it - more details on request

so basically, driving in normal automatic mode is perfect...no issues....BUT, I've recently been driving in manual mode so i can hear my new exhaust at higher rpms....it seems that after a shift from 1 to 2 AND from 2 to 3, i notice a slight stumble before it continues up in rpms....sometimes it's very slight and other times, it's pretty noticeable...no issues from 3 to 4 though....and once again, ONLY in manual mode wtf....

keep in mind I'm mechanically declined...but at this point i've ruled out rotator splints and muffler bearings :biggrin:

the best way to see what i'm talking about is with these three short clips....it seems to happen around the ~3200rpm range....and it's very noticeable in the second video going from 2nd to 3rd...

http://www.justwaitingtodie.com/rimjob/nsx/stumble wtf.mp4
http://www.justwaitingtodie.com/rimjob/nsx/stumble wtf2.mp4
http://www.justwaitingtodie.com/rimjob/nsx/stumble wtf3.mp4

sorry for the crappy camera work

 

[Gofastguy]

I'm having a problem getting the video to load and will try later but, I think I have the same problem as by the description. I have a 98 AT and in manual mode when I'm accelerating in 2nd and approaching somewhere around 4K - 5K RPM, the engine "hiccups" while under acceleration. It does not do that in either 1st or 3rd and it has always done that. I'm curious as to what's up as well. Almost feels like a torque converter locking up or something. I'd appreciate any ideas as well. Thanks -Robert

 

[anomaly]

i just uploaded them to youtube....sorry, should have done that to begin with, i just hate youtube with a passion....and yes, hiccup is a perfect word for what it's doing....i'd fullscreen these clips so it's easier to see the tach



<iframe src="http://www.youtube.com/embed/-wdVea-L6-k?hl=en&fs=1" allowfullscreen="" frameborder="0" height="349" width="425"></iframe>

<iframe src="http://www.youtube.com/embed/cPImkq-z8QE?hl=en&fs=1" allowfullscreen="" frameborder="0" height="349" width="425"></iframe>

<iframe src="http://www.youtube.com/embed/l7cEJkomuGc?hl=en&fs=1" allowfullscreen="" frameborder="0" height="349" width="425"></iframe>

 

[EdinKali]

It almost sounds like the bands? are slipping slightly right after the shift and then catching or what someone else mentioned possibly the torque converter locking up(a bit slower than one would hope).

 

[shawn110975]

First thing I noticed is your cars Idle is way to low it should be around 800-900rpm looking at the video your idle looked like 250-300rpm Not good...! that could be Idle control valve needs adjusting, spark plugs, vac leak, air filter, dirty throttlebody, coil packs,

take to a dealer sorry maybe some other auto owner can chime in.

 

[stevieray122854]

Being the owner of a '95 Legend with an A/T gives me some background in this, I suppose. The first questions I would have are (1) when was the last time the ATF was changed and (2) are you using Honda Z1 or DW-1 ATF? Reason I ask is that Legends are notorious for a really rough 1-2 shift and changing the ATF every 30K as well as the transmission filter really seems to help in overall drivability & smoothness. Also, it's been my experience that Honda automatic trannys really don't like anything other than genuine Honda ATF. The owner's manual will say you can use Dextron III in an emergency but I have no experience with that.

It's been debated ad nauseum over on the Legend Forums as to if it's really necessary to use genuine Honda fluids but I've never used anything else and never replaced a Honda A/T or even had to have one worked on. The only aftermarket fluids I use are Mobil 1 oil in the NSX and regular ol' Valvoline dino juice in the Legend. Also, unless you are the NSX's original owner, it would not surprise me one bit if your car had seen more than a few neutral drops which are really hard on an A/T.

 

[anomaly]

EdinKali, so if this is the case, we're talking pain in the ass to fix or no? can't pretend i'm familiar with torque converters...


shawn110975, thanks for catching the low idle...i'm going to take it in next week and have them address it...sparks were recently done, new air filter and when the o-rings were done around 75k, my buddy said my ignition coils were good....


stevieray122854, actually i'm not sure when it was last changed...i'm going to add it to my list of shit to do for peace of mind....i know when i went on my road trip, i stopped off at SOS and they said it was low and topped it off, but i'm going to have to check the paperwork to see what they put in it...


thank you guys very much for chiming in....anyone else with ideas?

 

[mlambert890]

Interesting... dont think it could be the TC honestly... the stall speed of an OEM TC is very low (prob ~1000RPM). The stall on a TC is basically the equivalent of how high you rev the engine before engaging the clutch on a manual.

The stall speed is the engine RPM at which the TC passes energy from the engine through the transmission. The torque multiplier is just that, the ratio of engine RPM to torque to the wheels.

The TC only works when the stall speed is reached. So a 3500RPM stall TC starts transferring (multiplying) energy at 3500RPM. An OEM TC is designed to give the best balance of energy efficiency given the RPM profile of the engine, "pickup" off the line, and gas mileage.

The reason I dont think its the TC is because of the mechanical nature of it, number one, so a failing TC wouldnt change its profile, and number 2 because you dont "feel" a TC in that way.

The fact that its *only* in manual mode, IMO, makes me think this is electronic. Do you have a code reader? Would be interesting to pull codes right after it happens.

 

[anomaly]

Interesting... dont think it could be the TC honestly... the stall speed of an OEM TC is very low (prob ~1000RPM). The stall on a TC is basically the equivalent of how high you rev the engine before engaging the clutch on a manual.

The stall speed is the engine RPM at which the TC passes energy from the engine through the transmission. The torque multiplier is just that, the ratio of engine RPM to torque to the wheels.

The TC only works when the stall speed is reached. So a 3500RPM stall TC starts transferring (multiplying) energy at 3500RPM. An OEM TC is designed to give the best balance of energy efficiency given the RPM profile of the engine, "pickup" off the line, and gas mileage.

The reason I dont think its the TC is because of the mechanical nature of it, number one, so a failing TC wouldnt change its profile, and number 2 because you dont "feel" a TC in that way.

The fact that its *only* in manual mode, IMO, makes me think this is electronic. Do you have a code reader? Would be interesting to pull codes right after it happens.

wow, thanks for the info there...i don't have a code reader, but i'll ask my mechanic buddy this weekend if he can pull something...he drove it once and i asked him to play with it to see if he could notice it and for some reason, he said it worked fine for him...figures....