boydsc33

hello , i recently bought a 1994 accord non vtec. my problem is the egr solenoid is on at idle. doesnt matter hot or cold engine, when i start the car the egr on and it idles rough. if i unplug the vacuum line to egr it smooths out. if i unplug the solenoid it smooths out. from what i understand the egr solenoid gets power from ignition and the ecu grounds the solenoid to open the valve. i have replaced the solenoid, all the temp sensors (for gauge, computer, and fans), the ecu, and double checked the vacuum line routings with the sticker under the hood. is there anything you know about this problem ? or did i just get a bad ecu ? which by the way the old ecu did the same thing which is why i changed it. im trying to get it to pass smog. i also checked the wire from ecu to solenoid for short to ground, but nothing.
thanks for any input.

faded215

Best bet is to pull a wiring diagram for it. The EGR solenoid should be a low side driver but just check to make sure. don't know what your setup is like but if it runs low side make sure it's not shorted to ground after the load before the ECU. This would cause your continuous problem. If no short after the load( if low side) it would be a transistor in the ECU that's shot.

boydsc33

what do you mean by low side driver ? 5 volt maybe