so my father has a 95 with a D15B7 with around 455,000 miles. (he drives far to work 6 days a week)

hes been having an issue and i dont even know where to begin and i dont even know if its tied in with another problem. so if you guys could hear me out for a few that would be lovely!

So it started with when it rains the car runs fine til you turn it off. then the CEL doesnt turn off and master relay doesnt kick in from anywhere from like 3-30 minutes, turning the fuel pump on and able to start the car. im not sure if we have resolved that yet. weve just covered the crap out of the fuse panel under the hood.

and the problem currently is he can be driving and it will start to cough and die just randomly. he drives around 60-70 miles each way for work so he has a lot of road but the other night it cut off 20-30 times.

hes using my DA for the time being and its not comfortable for him so please guys, any help would be a godsend.

in case you need to know, there has never been too much work done to the motor, just routine like timing belt, water pump (once a year) plugs and oil. master relay, ive changed the coil out once because i was a dumbass and blew it.

sorry so long but i really need to get this thing figured out!

 

Only when it rains? Moisture. Check the distributor cap and also in the area of the ECU for leakage.

 

Resolder the main relay, and sand and tighten the G101 ground wire attached to the thermostat housing.

 

ive done all that before. im starting to think its either in the ecu or the fuse box. the new problem is whats concerning us. it just seems to cough and die. regardless of the weather. but it will run and drive. its very intermittent. the ecu fuse looked like it had a fogginess to it. im about to drive it 100 or so miles here in a few. this stuff is confusing guys. any more ideas?

 

Mine, same model, same d15b7, same problem.

 

Rule out the main relay, and the ground wires on the thermostat. If it's not either of those, replace the ECU. Bad ECU's are rare, but this "delayed boot up" problem where the car will not start unless you leave the key on for several minutes until the CEL goes out, if not the main relay will usually be the ECU itself.

 

I replaced main relay and ECU. The behavior is the same.
When I drive many hours, civic start fine (2 sec to turn off)
When civic get wet (car wash or rain) delay around 1h to turn off the check engine light.

I don't know what to do

 

time to check wiring harness connectors at the shock tower for bad connections/frayed wiring. pull the fusebox from under the hood and make sure everything is connected well and sealed properly. water is getting in somewhere and finding a short, you have to figure out where.

 

I will check again. My civic dont get wet inside. NEVER get water inside. Somehow the humidity is damaging something

 

Does the problem only occur after the car has been driven in the rain, or does it also happen after idle in a garage while raining? I ask because it might be possible to pinpoint the problem to either humidity or bulk moisture.

 

In my Civic:
- when first start on the morning, delays 40/60 seconds to turn off the CEL and fuel pump work (in the garage)
- when I drive many hours and turn off the engine, if I try to start again, CEL works normal
- enlarging the time between last turn off engine and a turn on, the time starts to enlarging to (4, 5, 10 sec)
- when I washed or leave parked in the rain, Civic delay around 30min~1hour to turn off the CEL

I changed fuel filter and fuel pump = nothing new
Checked continuity on main relay, ecu, grounds, fuel pump = all ok, normal
I bought a brand new Main Relay = same behavior
I bought an used, but known-good ecu = same behavior

:^(

 

How well do you know the used ECU is good? Did the previous owner take it out in the rain?

In dry weather you can use a spray bottle to dampen various parts one at a time and see if that causes the malfunction.

 

I think I'll connect scanner OBD on the PLUG 3pin and Check for error or find/delete something wrong on ecu.