EFE Heater Power

[Andy]

Having with a problem with my car rumbling/burping while idling. Especially bad when cold when it first starts up. One of the things I’ve looked at was the EFE heater. When the car is first started cold, I have no power going to the EFE heater. The relay appears to be fine. There is battery power to the relay but no control power (blue wire). The car is an 88 lx. The Honda manual shows that there is an EFE control box which goes between the ECU and the relay, with the output of the ECU being wire A4. The shop supplement manual also shows the same arrangement. Unfortunately the manual appears to be wrong. There is no wire from A4. What looks to be the situation on the car is that the ECU output of B24 controls the relay. There is no other external box. B24 has no power on it, which appears to mean that either one of the inputs to the ECU or the ECU is bad. The four inputs that I know of appear to be OK (B22 battery, B23 ignition, ignition A11, and TW sensor A7). I have replaced the ECU with another ECU from a junk yard and nothing has changed. Anyone have any ideas? Thanks for any feedback.

[2oodoor]

the TW valves are probably going to be something to check for this, they are the first temperture active signal prompt. Those will then be either vacuum switches or electonic solenoid switches most likely, and I say that without looking at a schematic at the moment.
Judging by your logical application to theory I assume you have already checked for vacuum leaks, choke operation and deactivation, ignition timing, base idle air mixture, thermowax TW operation to vacuum advance control, and egr function????

[lostforawhile]

the TW valves are probably going to be something to check for this, they are the first temperture active signal prompt. Those will then be either vacuum switches or electonic solenoid switches most likely, and I say that without looking at a schematic at the moment.
Judging by your logical application to theory I assume you have already checked for vacuum leaks, choke operation and deactivation, ignition timing, base idle air mixture, thermowax TW operation to vacuum advance control, and egr function????

there is a temp switch somewhere but i can't remember where it only allows power below a certain temp

[Dr_Snooz]

What's an EFE heater?

[lostforawhile]

What's an EFE heater?

it's an electric heating grid built into the carb base, it helps prevent carb icing when the engine is cold , it's got a thermal switch somewhere and a timer module and relay.

[InAccordance]

this

[lostforawhile]

this

Gassyboygopoo?
s142.photobucket.com/albums/r112/Gassyboygopoo/?action=view&current=DSCN0396.jpg][IMG]http://i142.photobucket.com/albums/r112/Gassyboygopoo/th_DSCN0396

[Andy]

Measured output voltage from A7 going to the TW sensor and its 12 volts volts with the TW sensor disconnected. The book says it should be 5 volts. Indicates that the ECU is bad. Always a little suspicious of my conclusion when it says something is bad that I just replaced. I guess back to the jy. I could run my own control power to the relay and have a manual on/off switch, but i hate to rig stuff and it seems to me that if the ECU is the problem, than there could be other problems inside it also.

[lostforawhile]

you need a carb ecu? i can pull the one out of my car it's not being used anymore for anything do you need anything else from the efe circuit, controler timer anything like that ?

[InAccordance]

@lost - oh leave me alone! i made that photobucket as a joke years ago and thought it was a funny name

[Andy]

I think my ECU is fine after all. Still messing around with though. Thanks for the offer lostforawhile. If i figure something out i'll post back.