Sylvain Martin

I purchased a 2000 Honda Accord EX 4cyl for my son as a first car from a lady that had it sitting for 2yrs because the clutch was out. it started fine and engine ran smooth. After replacing the clutch we replaced the coolant sensor as it was providing no reading. works now. But now when you start the car, it idles fine but if you rev it at around 1500rpm it starts doing a fuel cut off and will surge between 500 and whatever RPM you are acheiving with the gaz pedal down. I checked it with my OBD tool and I can see it cut the injectors. there's no engine code after clearing the coolant temp sensor error. So far here's what I've done

-replaced clutch
-replaced coolant sensor in head
-cleaned IACV, I can see the flapper move when engine comes on. it's resting position is halfway open but it does fully open and fully close when the key goes to on, on start it goes halfway
-checked for vacuum leaks using propane; none, using brake fluid; none(I had my fire extenguisher ) and it does not appear it leaks. When I plugged the intake with my hand the engine stalled rather quickly and it kept suction on my hand
-I did not find a fast idle valve to check it per other google searches
-I've burped the cooling system 3 times to make sure all air is out, used the service manual procedure with opening the back plug during the fill.
-left battery disconnected overnight to reset ECU

I'm at a loss at this point. I've reconnected all the electrical connections on that side of the engine multiple times. So short of buying a new 100$+ IACV which seems to be functioning properly and I can't figure out any next troubleshooting steps. I'm open to suggestions!

holmesnmanny

It's sometimes possible to accidentally swap connectors. I would first double check that each connector is going with its actual sensor. The ecu cuts off fuel injectors when there is no throttle so it's possible that the tps is faulty so you can test that. One will have 5v, one will have ground and the other is signal voltage which will change as you open up the throttle

poorman212

99% sure you have the MAP and TPS connectors switched......what are the colors of the three wires currently plugged in the MAP sensor - or the color of the plastic connector.

Better yet, just switch them and see what happens

Sylvain Martin

So I did have the radiator switch and vtec pressure sensor connectors swapped.Double checked against the service manual for the wire colors. it's still surging at >1500rpm. So I unplugged the TPS, the idle went up but if I tried to rev it, it ran rough and died. My OBD scanner keeps saying the TPS is always reporting. 5.1%. I could see the values for the MAP sensor was going low while revving and high when idle. But remained between 15 to 28.
So possibly a bad TPS?

Sylvain Martin

OMG!!!! I had the TPS and MAP sensors swapped also. Thank you so much guys!

poorman212

Is the car all "happy" now?