I have a 97 accord that is surging at idle and while coasting down a hill. It also has a problem when it starts, the motor bogs down, sputters, backfires and has absolutely no power until the motor warms up, then runs ok but not great. I have codes P0108 and P0118. This car is also getting horrible gas mileage, somewhere around 15 MPG. Any clue what to look at?

 

P0108 MAP sensor circuit voltage high.
P0118 ECT sensor circuit voltage high.

Has there been any recent work or changes done to the car? History?

 

 

Prior to the water pump replacement(belt replacement as well?) the engine ran fine?

 

 

Did you do the work or did you hire someone?
Recheck all wiring connections have been properly attached. Including the ground jumpers and bonding jumper on the engine mount.
Check the end of the intake manifold, below where all the vacuum line attach there should be a main ground wire G101. Make sure that is still attached.

 

Yes I did the work myself. I checked all of the grounds and found no problems. I did find a faulty connection on the ECT, cut out and replaced with a new pigtail, no more code for the ect but still surging. Motor still tries to choke itself out and pops and backfires when cold. Just for giggles I unplugged the throttle position sensor while it was surging and it started to smooth with no surging. Could this be my problem or could something els cause the TPS to act this way?