Ok sooo I bought the car a week ago. Theres now a new timing belt, a full tune up, new fuel filter, new rad and hoses, new air filter, I put a new TPS in it last night and sdjusted it perfectly to .500 closed and 4.5 WOT none of this has fixed the problem. When I hit about 40mph the check engine will pop on when it starts to jerk it goes from 3000 rpm to 2500 rpm which creates a jerking feeling. I am starting to boil it down to a faulty TCU issue. My guess is that whatever controls the overdrive to turn off an on id messing up. As soon as it starts to jerk D4 will flash and CEL kicks on and all of a sudden the problem goes away which is why i think it has an overdrive problem. I checked the codes and the CEL gave me a TPS code, a electrical load detector code, and a water temp sensor. The Flashing D4 gave me just a coolant temp sensor. So am I even in the ball park eith the TCU guess? Someone Please help me fix tthis issue iv now spent so much time and money and cant seem to figure it out. Also I found a good tranny for only 250 could this be a tranny issue?

 

also I have read the other posts by other people with similar problems but I haven't found a post that has exactly the same problem plus I think I looked into some solutions that could fix those problems and haven't found a solution that fixed it yet

 

Pull the CEL and D4 light codes. The CEL and D4 are coming on for a reason, there is a code stored, retrieve it before throwing more parts at the car.

 

I did pull the codes and I posted them in my main description

 

You gave a description, not the actual code. Some online code descriptions and manuals have incorrect descriptions for codes.

 

Oh I see. I apologize the CEL codes are 6, 7, and 20. The D4 code is 10

 

Heres a little update so the CEL now reads 6, 7, 20, AND now 43. I replaced the whole TCU and now the D4 light stopped flashing but it still jerks. Im so confused please help! Lol

 

ECU
6 ECT - water temperature sensor
7 TPS - throttle position sensor
20 Electrical load detector
TCU
10 ECT - water temperature sensor
ECU
43 Fuel supply system


As you will note, none of the above codes are transmission or TCU issues. However a faulty ECT, TPS, and fuel supply issues will cause the engine to run out of tune. The TCU monitors TPS for throttle input/shiftpoints and ECT to prevent early shifting into 4th when the drivetrain is still cold.

Verify that the engine harness is not damaged. Would be pointless to replace sensors if the harness itself is faulty. 90-93 Accords also have a bundle of ground wires attached to the lower bolt of the thermostat housing, if this is loose, damaged, or not properly attached it can cause strange voltage issues which will affect the above mentioned sensors.
If the harness appears fine, then continue on to the sensors.

ECT is the TW sensor which is located on the head under the distributor.


TPS is the throttle position sensor. It is located on the opposite side of the throttle body, back probe the wires with a volt meter and look for a linear change in voltage. If there are dips, peaks, dead spots. The TPS will need replacement.

Get started on these items and get back to the forum.

 

So a little update. I now have changed the TPS, the coolant temp sensor and the TCU. None have fixed the problem. Thsnk you for posting mad mike that was a great deal of help. Next I will inspect the wiring...do I check it coming from the ecu itself or where do I check it? Also what is a electrical load detector? This car is frustrating me bad I have been getting 17 mpg since I bought it!!

 

Did you test any of these parts or have you just been replacing them?
If you did test them did you notice any strange or erratic voltage readings?
You will want to check the whole harness. Look for any damage to the harness to see if any of the wrapping has been damaged(torn/crushed/etc) or any modifications done. Also look for any repairs or modifications.

If the harness ground wire(s) is loose/corroded/damaged it will cause erratic behavior. Check your water outlet(thermostat housing) for the ground harness.
Check your driver side engine mount, there should be a short two wire bonding jumper. One large gauge wire will go from the body side to the engine side of the mount, and then a smaller gauge wire going to the valve cover.

If you can post some pics of your engine bay, and of the harness.
It is a device located in the underhood fuse box. It combined with the ECU will command a higher or lower load from the alternator.

 

So I bought a digital meter and tested the plug that plugs into the coolant temp sensor. It reads 5.16 is that the right voltage? Also today I unplugged the tps and drove the car and it stopped jerking and seems to run smoother? I found this odd. Am I crazy? I thought I tested the voltage on the tps right when I installed it but maybe not? What is the correct process to test the voltage where do I put the red and black exactly?

 

I just drove the car with the TPS unplugged and I noticed that at about 20-30 mph it will feel like the tranny slips. If it's plugged in it won't slip like that. And when I am driving going about 40-60 mph with the TPS unplugged it does not jerk at all. But when I plug it in it will jerk. So to me it sounds like the problem is revolving around the TPS am I correct you think? I think I'm starting to get closer...also the CEL will come on almost like clockwork at 28mph. Which also I just checked the codes are the same 6, 7, 20, and 43..

 

Did you check your harness? Have you located the grounds mounted on the thermostat housing? What condition is the wiring in? Can you take pictures of your harness?




You have multiple faults, with no changes after sensor replacement.
I highly suspect the grounds may not be attached, or have corroded.

I cannot see your car, help us help you.

 

i am having trouble posting pictures. yesterday i checked the grounds under the thermostat. it does look a little corroded...also while i was trying to get to it i was unplugging the plug from the egr valve i believe and pulled the green wire that was hooked into the plug! i took off the electrical tape and realized that it was previously broken and someone did a really poor job at trying to sauter it back together...is that related to a possible jerking? and the ecu looks perfectly fine

 

IIRC the ground wire on the TPS/EGR/MAP are all shared, not only at the bonding jumper but also along the harness.

If EGR is not properly functioning the lift sensor will not be properly activated, if this happens the ECU will not know what the EGR valve is doing. This may lead to bucking and misfiring.

If any wire is damaged or corroded it will need to be fixed/cleaned/repaired.

If there are any other non factory modifications done to the harness, tape, splices, some shitty alarm/stereo install. Then investigate them and repair/replace the damage.

Fix all the damage you see first. Then get back to us.

If you cannot post pictures, verify that the KB size is smaller than the limit of the given file type. You will have to scroll down the manage attachment screen to see what the limits are.

 

Sorry for bringing this up years later but I also have the high speed jerking issue with my 92 accord LX and the only CEL code I get is 43. Wondering if this was ever fixed. Jerking stops when CEL comes on but horrible gas mileage. Could this still be a grounding issue? I replaced Throttle body/TPS and then this problem started.