I've tried searching for this issue here and haven't found anything so I thought I would start a thread. I recently bought a clean little 1996 Honda Accord 2.2 Auto with 154,000 miles. I drove the car home and parked it until I could do the TB service because it had never been changed according to the owner, who was the original owner. I also changed out all of the AT fluid with Z1 by draining the pan, cleaning the plug(It had quite a bit of gray crud on it nut no chunks), connected a piece of rubber hose to the supply line and ran that into a marked clear plastic jug, ran the car for about 5 seconds, added that exact amount back in and repeated until the fluid was bright pink at the bottom of the hatch marks on the stick and then added a NAPA/Magnefine inline filter to the return line. I didn't drive it enough before that to know any and/or all issues it may have had but the shifts were firm, it didn't slip in any of the gears and the D4 light wasn't blinking, which is why I felt confident buying the car.

Well now that I've driven it for a couple of weeks it still shifts firmly with no noticeable slippage but it's a slight delay and a little wonky when you pull it into Drive. It feels like it goes into Drive, then almost like it engages a little more. Not a clunk or anything like that but with foot on the brake and pulled into Drive you can feel, and hear, the engagement, then like it engages a little bit more instead of fully engaging in one action. Under light throttle the transmission took longer than I expected to shift. If you go with half throttle it seems to shift early if anything, but that might be normal for these cars. The other thing is it seemed to downshift needlessly when slowing down to make a slow speed turn, and if you let off of the gas it automatically disengages as soon as the MPH hits 35. I mean like clockwork! If you're doing say 45 and let off of the throttle and let the engine slow the car down, as soon as the speedometer hits 35 it's like it goes into neutral and the RPM's immediately fall.

I rechecked the fluid and it was just below the bottom hatch marks so I added fluid, almost a full quart, until it's now at the top hatch mark and the downshifting issue seemed to improve as did the part throttle gear shifting. I checked the solenoid packs and the top ones click but both seem a little weak and one of the solenoids on the bottom solenoid pack(the one with the green wire) is audibly weaker sounding than the other solenoid on that pack. Do any of those solenoids have anything to do with any of my issues? Could a mount be causing the issue I have when I put the car in Drive? Thanks for any and all responses as I'm not as knowledgeable as most here!

 

you can pull the solenoids and clean the gasket, it could be blocked

 

Thanks for your reply! When I did the TB service and A/T fluid change I pulled the top one and the filter screen was clean. What does the top solenoid control and what does the bottom one control?

 

The bottom one controls the gear shifts, the top is shift lock. Try cleaning the bottom one.

 

TB service?
These transmissions do not have a readily accessible filter to change.Best way to keep the filter from becoming clogged is to drain and refill 3X out through the sump drain. You want to draw and drain the crud out. Using the AT pump to replenish fluid and drain the trans will not allow any of the junk to be removed. You want to drain it so that goobers and gunk are removed. Using the sump only will only impact the junk into the filter. Not to mention the drain method is helluve a alot easier and not messy.
I've always noticed this with my cars. Recently while doing some work with the car lifted I noted that the delay corresponded with the shift solenoids actuating. There is a delay from when you shift the mechanical/hydraulic side to when the shift solenoids click and then the car is fully in gear. No idea if this is how the car has always been. Only noticed it after replacing mounts some time ago
If the fluid is low the transmission may be starving for fluid, no fluid no go. Low fluid will cause a shift delay. Verify the transmission is fully of fluid, Warm up the engine place the trans in every gear for 5 seconds, place it back into Park, pull dipstick, wipe, reinsert, pull dipstick, check fluid level.

Always charge each circuit when replacing trans fluid, Older transmissions internal seals may allow for faster leak down of a circuit, simply refilling will not always show the true capacity.

There are a few adjustments to check with your car.
Verify the throttle cable to throttle body has no slack in it. A sloppy cable will give up total throttle opening and will delay acceleration.
Verify the throttle valve cable to the transmission(from throttle body) is not too tight or loose. The lever on the front of the transmission should begin to move when the throttle blade itself begins to move.
If it is loose there will be a delay in upshifts, too tight and the trans may shift early.
If upshifts are erratic or overly firm, check the NC/NM sensors on the right side cover(same side as drain plug). Remove and inspect that they are not covered in slurry, wipe them clean and reinstall.<br />If downshifts are erratic, check the VSS. It can be removed and taken apart further to verify it is not dirty. Clean if need be.

TPS is also a huge factor in how/when/if the transmission upshifts.
A dead spot on the TPS may not set a CEL light, but it will cause a delay or no upshift condition.
Backprobe and verify the voltage changes linearly when opening and closing the throttle. Any dead spots or erratic voltage changes may be due to a damaged TPS.

Upper pair control TC lockup. Lower pair are the shift solenoids.
Pull the solenoid pairs and check the O rings and filters are not damaged or gummed up. Use some brake cleaner inside the valve to blast out the ports with the valve open, there may be varnish build up inside that may be causing the pintle valve to stick. Gummed up enough you may not net a proper 'click' when actuating.
There is a delay from when the snifter selects a gear to when the shift solenoids actuate. I do not know if this was originally designed this way to reduce shock loads when selecting a gear, or if it is from a component in the TCU/PCM going out of spec. Every H4A(90-97) trans I've ever driven does have this two step engagement feel. Granted that's only a handful of cars but it seems to be normal.

There is more detailed info in the 'techauto' link in my sig.

 

Thanks for the replies! Sorry Mad Mike but been very busy lately. "TB service?" I was referring to the timing belt. Replaced the TB, BS belt, WP, tensioners, tensioner springs, oil pump O-ring, seals etc.. I checked the Throttle valve cable and it was a little loose and didn't take much to take the slack out. I took the bottom solenoids off and cleaned them and now both have a the same crisp sound when powered. The delay from park or neutral to drive is still there, and the delay still isn't consistent. Sometimes I would consider the delay acceptably 'normal', but other times it's obviously more than normal. When it's normal, it feels like it fully engages then you feel a very slight nudge and then it fully engages. When it's longer than normal when you put it in drive you can barely feel it trying to engage then you can feel it fully engage. When normal the initial engagement is firm but the secondary engagement is very slight, but when not normal the initial engagement is weak but secondary engagement is firm. If it was a minor delay, and consistent, I would chalk it up to 'normal' delay and could live with it, but when the initial engagement is weak, it makes me wonder if it will fully engage or not. Do the NC/NM sensors affect drive engagement? Any other suggestions? Thanks again!

 

I find that when the car is cold there is a greater delay, I believe this is a combination of the fluid draining down and the circuits needing to be fully charged before full actuation of components to put the vehicle in gear proper.

NM/NC solenoids monitor Main and Counter shaft speeds. If these are fouled the upshift may become erratic. They are hall effect(magnetic pickup) sensors, TCU/PCM uses them to monitor shaft speeds and when reaching the correct speeds(depended also on throttle position via TPS and TV cable, as well as MAP and Thermo sensors) which will then command an upshift. In turn VSS is what the TCU/PCM uses to monitor shaft speeds for down shift control.