Crazy idle
#11
12-27-2012, 09:49 AM
Ok guys I contacted the guy I bought it from to get more info so maybe this will help you guys help me.. 
So the stock motor was the D16z6 swapped to a d15b. The throttle body, rail and all are from the z6 and he had several people tell him it was the TPS, sounds right since I'm getting backwards readings, right?
So the stock motor was the D16z6 swapped to a d15b. The throttle body, rail and all are from the z6 and he had several people tell him it was the TPS, sounds right since I'm getting backwards readings, right?
#12
12-27-2012, 12:37 PM
You just need to modify the harness (switch the two outside wires) on what you have.
Replacing the TPS with a new one won't change anything-- it would still work backward.
Replacing the TPS with a new one won't change anything-- it would still work backward.
Last edited by mk378; 12-27-2012 at 12:41 PM.
#13
12-27-2012, 02:30 PM
Well I switched outside wires and it dont jump up and down but the idles is high at about 2000rpm. I don't have a volt meter to get a reading but guessing it's not .5 at cl.. Also took it for a spin to see if it would hit vtec easier and theres still a lag (putter like it topped out) then it hits it. What next guys?
#14
12-27-2012, 08:57 PM
Of course, check for ECU codes. Do not expect the car to work properly with the CEL on.
Make sure the throttle plate closes all the way with the gas pedal not pressed. Confirm the throttle cable goes slack, adjust the two nuts on the outer housing if needed. Also someone may have tinkered with the stop screw on the throttle body. That screw is NOT used to adjust the idle speed. It should be set up so the plate closes all the way but doesn't slam against the sides of the throttle body. Then leave it there, set and forget. Idle speed is controlled by the computer and the air screw.
After confirming that the throttle plate is properly closing, then check TPS voltage again and adjust TPS if necessary.
Unplugging the IACV on the back of the throttle body should cause the idle to drop to an abnormal low speed but not stall. If it still idles very fast with the IACV disconnected, excessive air is getting into the manifold (possibly bad IACV or FITV). First check is to remove the intake pipe and see which if any of the bypass holes in the side of the throttle body before the plate are sucking air. One should lead to the IACV, one to the FITV, and one to the air adjust screw on the top of the TB.
Also double check other basic stuff like the cam and spark timing, fuel pressure (if it has an adjustable regulator, get rid of it and go back to stock), etc.
Make sure the throttle plate closes all the way with the gas pedal not pressed. Confirm the throttle cable goes slack, adjust the two nuts on the outer housing if needed. Also someone may have tinkered with the stop screw on the throttle body. That screw is NOT used to adjust the idle speed. It should be set up so the plate closes all the way but doesn't slam against the sides of the throttle body. Then leave it there, set and forget. Idle speed is controlled by the computer and the air screw.
After confirming that the throttle plate is properly closing, then check TPS voltage again and adjust TPS if necessary.
Unplugging the IACV on the back of the throttle body should cause the idle to drop to an abnormal low speed but not stall. If it still idles very fast with the IACV disconnected, excessive air is getting into the manifold (possibly bad IACV or FITV). First check is to remove the intake pipe and see which if any of the bypass holes in the side of the throttle body before the plate are sucking air. One should lead to the IACV, one to the FITV, and one to the air adjust screw on the top of the TB.
Also double check other basic stuff like the cam and spark timing, fuel pressure (if it has an adjustable regulator, get rid of it and go back to stock), etc.
Last edited by mk378; 12-27-2012 at 09:06 PM.
#15
12-28-2012, 04:21 AM
Of course, check for ECU codes. Do not expect the car to work properly with the CEL on.
Make sure the throttle plate closes all the way with the gas pedal not pressed. Confirm the throttle cable goes slack, adjust the two nuts on the outer housing if needed. Also someone may have tinkered with the stop screw on the throttle body. That screw is NOT used to adjust the idle speed. It should be set up so the plate closes all the way but doesn't slam against the sides of the throttle body. Then leave it there, set and forget. Idle speed is controlled by the computer and the air screw.
After confirming that the throttle plate is properly closing, then check TPS voltage again and adjust TPS if necessary.
Unplugging the IACV on the back of the throttle body should cause the idle to drop to an abnormal low speed but not stall. If it still idles very fast with the IACV disconnected, excessive air is getting into the manifold (possibly bad IACV or FITV). First check is to remove the intake pipe and see which if any of the bypass holes in the side of the throttle body before the plate are sucking air. One should lead to the IACV, one to the FITV, and one to the air adjust screw on the top of the TB.
Also double check other basic stuff like the cam and spark timing, fuel pressure (if it has an adjustable regulator, get rid of it and go back to stock), etc.
Make sure the throttle plate closes all the way with the gas pedal not pressed. Confirm the throttle cable goes slack, adjust the two nuts on the outer housing if needed. Also someone may have tinkered with the stop screw on the throttle body. That screw is NOT used to adjust the idle speed. It should be set up so the plate closes all the way but doesn't slam against the sides of the throttle body. Then leave it there, set and forget. Idle speed is controlled by the computer and the air screw.
After confirming that the throttle plate is properly closing, then check TPS voltage again and adjust TPS if necessary.
Unplugging the IACV on the back of the throttle body should cause the idle to drop to an abnormal low speed but not stall. If it still idles very fast with the IACV disconnected, excessive air is getting into the manifold (possibly bad IACV or FITV). First check is to remove the intake pipe and see which if any of the bypass holes in the side of the throttle body before the plate are sucking air. One should lead to the IACV, one to the FITV, and one to the air adjust screw on the top of the TB.
Also double check other basic stuff like the cam and spark timing, fuel pressure (if it has an adjustable regulator, get rid of it and go back to stock), etc.
Being new to all this I;m not sure what (CEL, IACV or FITV) is but will google and search to figure out. I work a double shift today so will not be able to check anything till saturday.
#16
12-28-2012, 02:47 PM
CEL = Check Engine Light, the yellow light on the dashboard with the engine icon. On used cars it is common for someone to conceal a problem by taking the bulb out. Test that the light actually works by turning the key on but not all the way to start the engine. It should light up for 2 seconds then go out.
IACV = Idle Air Control Valve (officially honda calls it the EACV, Electronic Air Control Valve). This is a solenoid operated valve typically mounted on the back of the throttle body / intake manifold. The ECU (Engine Control Unit, i.e. computer) drives electricity to this valve to open it and supply a controlled amount of filtered air bypassing around the closed throttle plate into the intake. The amount of air dictates how fast the engine will idle.
FITV = Fast Idle Thermal Valve. Usually mounted on the bottom of the throttle body, this valve is a mechanical device that works like a thermostat. If the engine coolant (supplied through small hoses to the valve) is very cold, it opens to let even more air into the intake to keep the engine from stalling on winter starts. Once the coolant rises above 60 degrees Fahrenheit it should be completely closed. If it gets stuck open, the engine will idle too fast when warmed up.
Speaking of that, the ECU senses engine temperature and adjusts the idle speed through software, slowing it down after warm up. If the engine never warms up (thermostat stuck open) it will continue to idle fast. Check that the temperature gauge on the dash comes up to normal temperature, about halfway up, and stays there through all driving conditions. All idle problem tests that involve running the engine must be done with it at normal temperature.
IACV = Idle Air Control Valve (officially honda calls it the EACV, Electronic Air Control Valve). This is a solenoid operated valve typically mounted on the back of the throttle body / intake manifold. The ECU (Engine Control Unit, i.e. computer) drives electricity to this valve to open it and supply a controlled amount of filtered air bypassing around the closed throttle plate into the intake. The amount of air dictates how fast the engine will idle.
FITV = Fast Idle Thermal Valve. Usually mounted on the bottom of the throttle body, this valve is a mechanical device that works like a thermostat. If the engine coolant (supplied through small hoses to the valve) is very cold, it opens to let even more air into the intake to keep the engine from stalling on winter starts. Once the coolant rises above 60 degrees Fahrenheit it should be completely closed. If it gets stuck open, the engine will idle too fast when warmed up.
Speaking of that, the ECU senses engine temperature and adjusts the idle speed through software, slowing it down after warm up. If the engine never warms up (thermostat stuck open) it will continue to idle fast. Check that the temperature gauge on the dash comes up to normal temperature, about halfway up, and stays there through all driving conditions. All idle problem tests that involve running the engine must be done with it at normal temperature.
#17
12-29-2012, 03:36 PM
Thank you so much for all the help. I'm so pumped right now after completing my first trouble shooting fix. After swapping wires on the TPS all was needed was adjusting the idle stop and throttle cable, of course making sure my volts where in range. Car runs smooth now from bottom to vtec and I am now hooked on the project.
After swapping wires on the TPS all was needed was adjusting the idle stop and throttle cable, of course making sure my volts where in range. Car runs smooth now from bottom to vtec and I am now hooked on the project.
Thread
Thread Starter
Forum
Replies
Last Post
tayglo
Mechanical Problems & Technical Chat
7
12-19-2015 05:53 AM
03civex
Mechanical Problems & Technical Chat
15
10-28-2008 08:20 PM
jm0597
Mechanical Problems & Technical Chat
10
04-25-2008 10:26 AM
