Hey y’all, I’ve been lurking around for a bit here getting some info on how to fix up a new to me 1994 Accord EX wagon automatic with 68k miles on it, it used to be an old lady’s car and has was well maintained. With y’all’s help I got the main issues fixed but now some weird stuff is going on and I haven’t come across any info/wanted to get y’all’s opinions. Here is the run down since I’ve had the car:

When I first met it, it would do the crank no start thing when it got hot in the car. I changed the main relay and it was working fine and I was driving it to and from work, then as the weather started getting warmer it would have intermittent trouble starting/not start

Finally got it home and parked it for a while, and eventually replaced the distributor which did not fix the problem, but it needed to be replaced because it had a code 9(I think, it was some related to a sensor in the distributor) it was also leaking oil from it like a MF.

I found out that it was the ECU after I put it in the freezer for 30 minutes and plugged it in and the car fired right up until eventually stopped starting as the ECU got warm. At this point the car didn’t have any plates so I didn’t drive it really at all thinking it was good to go.

Recently I replaced the rotted out muffler and finally drove it around town a bit, and noticed the acceleration is lagging pretty hard when I accelerate from a stop, like it will take a couple seconds to get up to any speed. When I’m around 30 mph sometimes when I put the foot on the gas it will downshift to the point where I will lurch forward in the seat. Otherwise it drives very nice except for the lagging acceleration. Before I did any of the repairs the car felt quite a bit zippier and didn’t seem to have any of the lagging acceleration or weird downshifting.

I took out the TCM and put it in the freezer and plugged it in and it seemed to drive normal, but I tried it a second time and it felt odd on that trial and I will probably try it again to see what’s up because that is the easiest test I’m capable of performing at this time anyway.

My thoughts on this is that the car has been sitting in full central Texas sun for a couple years minimally driven, and since the main fuel relay and ECU soldering went bad, it would make sense to me that the TCM could possibly be bad as well and I’m just now finding out considering it’s hot AF in Texas at the moment.

I’m curious if y’all had any input or areas
to check next, I am new to Hondas and I love this thing so any tips or thoughts or advice/encouragement are greatly appreciated


ps the plugs were changed to NGK after doing the main fuel relay and sorry for the novel 🤣😖




cheers,
Chris

 

I've got a 1994 Honda Accord LX Wagon that I've swapped the head and ecu out for the Vtec EX counterparts. I ran into a few things I had to handle that may help figure out what's going on with yours as well as "mileage may vary, age of the vehicle, replacement part" situation. A couple years ago I wound up replacing the fuel pump and main relay with cheapo units when the shifting got rough and I had some starting issues. For the fuel pump I cut an access panel to make it easier so I wouldn't have to drop the tank. I did a video on that here:


When I did my Vtec head swap and wiring I swapped in a junkyard ecu. It worked fine at first then a few days later I had strange intermittent issues: Starts up in the beginning then you could shut it off when warm and no start, start fresh but then chugged and acted horrible, stall, etc. The dynamic would change if I brought the ecu inside and brought back out cool to which it would work then not work. It was throwing a code 9 as well. I rebuilt and resealed the distributor. (same here with crazy oil leak from the internal distributor shaft oil seal) Still throwing code 9 and having issues. Turned out the capacitors on the ECU's board were bad. They weren't bulged on the tops or blown they were bulged out on the bottoms and the only way to see it was to remove them.
I did a video on which ones went bad in that ecu here:


I set the ecu to the side, put the non vtec one back in to limp on, and bought a used good vtec one off of Ebay for like 150 USD. Put it in and all issues went away and worked fine for quite a while. Then one night about a month ago I'm driving and pull off the highway. I'm sitting at an intersection and the car chugs for a moment and then just cuts off. ALL the lights come on. Check engine light is solid & the D4 transmission light is blinking. Horrible electric burning smell in the cabin. Wont start back up. The main relay feels hot as hell to my hand. Had to push it down the road. Troubleshooting showed No spark, No sound of fuel pump coming on, main relay didn't look the best but was technically ok. I took the distributor apart and all parts tested out okay with a multimeter. Checked the fuse boxes and all the fuses were fine but the under hood one smelled like an electronics warehouse burning down. Found the source of the smell, apparently the ELD system gave up the ghost and that's what the smell was. I opened up the ECU and bingo the ELD had taken out a capacitor on the board and when the capacitor went it blew a hole half way through the ECU's pcb board. I got a ride to go get my spare ecu. I used a 820 ohm resistor on the ELD connector in the fuse box to bypass the ELD which I did a video on. (This makes it so that the alternator is always charging like other cars usually do. The ELD system normally works by turning the alternator charging on and off in attempt to save some mpg) I put my spare ecu in along with swapping out the main relay with another to make myself more comfortable and drove back home. I did an intense repair on the ecu with a new capacitor and it worked. These computers are getting older and ours are 29 years old now. With this age the capacitors are in my opinion well past their life time. They can start failing and give intermittent issues and then when they do fail they can either leak everywhere and stop working or straight up explode and damage the board like mine did. There's alot of early 90's Honda Beat ecus and 90-93 Accord transmission computers that have had capacitor failures recently. So our Accord generation is pretty much next in line of age. The Transmission control module computer is no exception. They have capacitors in them as well. Fortunately I haven't had any of those go yet. The best bet first would be to disconnect your battery and take both your ecu and tcm out, put them both on a table, and open them up. Look around the boards and especially at the capacitors. (big round vertical barrel looking components) and see if you see any weird leaky liquids or dark areas around them. See if any of the capacitors have domed tops (supposed to be flat) or look like they are trying to lift off of the board. If you see anything strange or even slightly off with the ecu you can get a Honda ecu capacitor kit for a Civic from ebay (commonly used to replace capacitors in PR4 P05 P06 P28 P30 P61 P72 Civic ecus) from that kit you have all the caps you need for your Accord and are basically left with a spare that wont be used since the civics have an odd extra. You can have them soldered in at a tv or electronics repair shop somewhere for affordable or if you have a 12 dollar chinese adjustable soldering iron, some flux, desolder wick, and some solder you can replace them yourself at home. Hopefully sharing this will give you an advantage of some sort.

If you want to see the carnage caused by the capacitor exploding and how I fixed it or how to bypass the ELD system I did a video on it here:


Off topic but good info to have a couple years ago I had to replace the torque converter in my automatic transmission. Transmission was totally fine but torque converter was done from age and mileage. Regardless of what individual part numbers they give you for torque converters you can mix it up a bit. I pulled a recently replaced new torque converter from a wrecked 1997 Accord Sedan for mine and it was a different part number and spec but really no noticeable difference. Baby got to 140 mph shifting smooth through all gears with new fluid during testing before the head swap. If you ever need to you can also use a transmission control computer from a sedan model and it will work for your wagon as well. The shift points are slightly different since the wagon has a different final gear but it works fine. I tested that with one from a 1994 EX sedan. If you ever have to fall back on a non-vtec ecu to run your wagon it'll work to limp by on but it's better to shift through the gears by hand while you are using it and don't floor it in lower gears to over 4000 RPM because it will conflict and you'll get some nasty spitting and feedback you don't want. Hopefully in the next year I'll figure out what components to solder in to convert the non-vtec Accord ecus boards over to vtec and make a video on it.

If there's any questions or help you need with your wagon don't hesitate to message me. I'm constantly trying to find ways to improve designs or optimize my Accord and I learn alot along the way. Alot of stuff I have to figure out for myself because I can't find certain information.

 

Yo dude thank you for the response. I checked out your videos and subscribed to your channel, I’m new to Honda stuff so good to be able to talk to fellow wagon owners.

I inspected the old ecm a while back but not sure what I was looking for at the time. Will check out the computers again soon.

I’m posting again with updates since I’ve been driving the car to work and back the last week or two and I’ve noticed some things.

1. The car drives much better in the morning on the way to work compared to on the way home
from work after it’s been parked in the sun.

It accelerates much faster in the morning but in the afternoon there is still an intermittent
severe lag in acceleration from a stop.

2. When I reach around 60-65 mph there is a very slight stuttering when I am on the accelerator, which is concerning. It doesn’t feel like a full on misfire but I’m not sure.

3. The MPG has drastically decreased compared to when I was driving before I replaced the computer, distributor, and muffler. Originally I could fill up and drive to work for almost two weeks before filling up, getting almost 400 miles per tank. Now I’m getting about 210 miles per tank and it roughly came out to 17mpg. The only thing different I can think of is I’m running the AC more than when I was getting 400 per tank. I haven’t had an operational AC in my trucks the last 8 years so im kinda unsure how it affects everything, but sure hope that it doesn’t cause that much decrease in MPG.


Any thoughts or advice is greatly appreciated 🍻


edit: I was also curious if possibly installing the new computer with battery hooked up could cause some sort of issue or if I need to reset it So the ECU and TCU can become one again? I’m not sure how it all works but realized i didn’t unhook the battery or reset anything when installing the new ECU

 

For concerns about the ECU and TCU being plugged in fresh while the battery is connected I don't recommend doing it but I've "hot plugged" in the computers while the battery was connected with no issues. Using the A/C will definitely hit the mpg in the ***** a little bit since the ac compressor puts resistance on the engine through the serpentine belt that turns it. For that intermittent stuttering when warm higher in driving range I would grab up a cheap ebay intake air temp sensor and switch it out. Our '94 Honda Civic had issues just like that with no CEL or code. When we took the IAT out it was worn out. Looked all melty. If yours looks like the one on the right when you take it out that's most likely it.


I've had throttle positioning sensors exhibit some of the same signs and have to be replaced but that's mainly been on Civics in all temps and ranges. I haven't had to replace one on an Accord yet though. If you ever do there are videos on how to install and calibrate them with a basic multimeter. Most commonly on these Accords your throttle body could be dirty or gunked up and just need a good cleaning. There's lots of passages in there. There's also the egr and egr passages on the F22B1 & F22B2 intake manifolds that get clogged and cleaning those will raise your mpg. Below is what that looks like. EGR is on the far left, hole on the left is plugged solid with carbon, hole in the middle is being cleared with a flathead screwdriver, and the hole on the right has been cleared out. The sandwiched plates that you unbolt to get to this can be scrubbed and cleaned with a wire brush and some carb or brake cleaner and reused as they are just metal.