Hey guys, long time lurker here. I have a 96 F22B1 Accord EX sedan with auto tranny and 170,xxx miles that has what I can best describe as a "shuddering" from the engine and/or tranny under very light throttle (like 5 degrees off idle) at 40-45MPH. It only occurs in D4 and giving it more gas or letting off makes it go away. I have no knowledge of how this car was maintained before I purchased it in March.

So far I have tried many fixes from these very forums, including:
Cleaned EGR valve and passages. All passages were clogged but now spotless
Replaced spark plugs with NGK's (gapped properly).
Drained and filled tranny fluid (3 times) with Genuine Honda fluid and new washer.
Tires balanced and rotated.
Replaced PCV valve

There are no codes in the computer and I have also reset it by pulling the fuse.

This is my first Honda and I am stumped.

Any ideas?

Thanks in advance

 

what color was the transmission fluid that you replaced? was it still red or was it brown/black or burnt smelling?

 

It was brown but not burnt smelling. There was a horrendous amount of shavings on the magnet too. If it matters, I just figured out that the vibration starts occuring around 1800-1900rpm. Torque converter clutch?

 

I read awhile back they fail due to insufficient oil flow through a jet or something to that affect. Does it seem to jerk when you left off the gas going down with a slight grade at all? I noticed mine does that sometimes. Also, did you notice any improvement after getting the egr ports cleaned?

 

I don't notice any jerk going down a slight grade. It does downshift at closed throttle going downhill due to the "grade logic." In fact other than what could be this converter clutch problem, the tranny shifts and behaves just fine. No leaks, no rpm flares between gears, no slipping whatsoever.
The only noticable difference after cleaning the EGR ports was smoother acceleration. Then again, I didn't have the telltale CEL indicating they needed cleaning either.

 

I'm curious. Since this problem only occurs within a very limited range of throttle angle, could a faulty or out of range TPS cause the converter to lockup at too low of an RPM (aka low line pressure) which would cause the clutch to slip but yet not set a code?

 

Alright just wondering. I don't know if it would be the tps, you could always test it with a voltmeter. I noticed after cleaning my IACV with throttle body cleaner, it rarely jerks now going down a slight grade, you might want to give that a try I think I'm going to try GM synchromesh for my next transmission fluid change, I've been hearing good things about that. Good luck!

 

Yeah, I was going to do the IACV next since even on hot days >90F the engine idles at 1500RPM until warmed up. From what I've read that behavior is normal... in the winter. Certainly can't be correct during this heatwave the midwest is experiencing. Thanks for all the input I've received so far. If anyone has further suggestions, I'd love to read them.

 

Yeah it could be TPS. Just do a search for how to test and calibrate it, there are threads about it.

 

here is a link for the TPS https://honda-tech.com/forums/honda-accord-1990-2002-2/1993-accord-dx-tps-removal-2822004/

 

Thanks Jmb106jr! I just got back from buying an analog meter. Going to test it now.

 

Well, the TPS test results were mixed. The meter showed .5 volts at closed throttle, made a smooth clean sweep as I opened the throttle but stopped at ~4.15 volts at WOT. Isn't it supposed to go to 4.5 volts at WOT? I thought they usually developed a flat spot and the meter would jump around when within that range. Never heard of one being within range everywhere but at WOT. Still stumped.

 

Not to bring up an old thread, but I wanted to let everyone know that the problem is fixed.

I'm not sure what happened, but over the last few months the shuddering has slowly disappeared to the point where it is no longer noticeable. My best guess is that a previous owner or mechanic put non-spec fluid in the transmission which worked its way into the clutch plates and it simply took a while for the Honda ATF to displace it.

Thanks again to all those who offered up their ideas.

 

toker2,

thanks for the upedate. I'm a new Honda owner with a 96 Accord. I'm getting that shutter a speed as well. I also noticed that the torque converter was locking-unlocking (and firmly) with very little throttle movement, usually at highway speeds.

Did you do the drain/fill 3x routine before adding Honda Z1 fluid?

 

Yes, I drained it (about 3 quarts came out) and refilled with Genuine Honda fluid. Waited a week and repeated the procedure. Then waited another 2 weeks and did it a third time. It took 2-3 months after that final drain/fill for me to notice an improvement. Good luck!