Civic 2000 D15Z6 engine swapped (Many issues)

[shabbir.1]

This screw is sort of fine adjustment, if the RPM is out of range by a great amount then this screw should not be touched.

Either throttle plate is not sitting at the right position or there is some air leaking from the TB mating surface with the IM. The mechanic hasn't fitted ir properly.

[hasankhurshid29]

is there any gasket present behind the TB or your mechanic has used silicon for this purpose as one can see silicon residue everywhere.If the throttle cable has no tension in it and the idle adjust screw is not fiddled with, then there must be some air leaking inside the IM.

Before putting back the hoses all silicon residue is removed and I don't know about the gasket present or not but idle adjust screw was fiddled by me and some other mechanic many time before this throttle cleaning. But last time I try to set it, I couldn't increase or decrease the idle (I think at that time car was not having auto fan)

[hasankhurshid29]

This screw is sort of fine adjustment, if the RPM is out of range by a great amount then this screw should not be touched.

The rpm is around 1500

[shabbir.1]

When the engine is running put your finger on this screw and check if you feel air sucking inside, RPM should drop when you put your finger firmly over this screw.

Check the gasket behind the TB it has to be there otherwise air will leak inside and you can't do much about it. Also check the o-ring beneath the MAP sensor it must be soft and of proper size.

[Hassan1991]

set the rpm from the screw.
vss should also be connected to ecu. check it is connected or not.

[hasankhurshid29]

Nothing happens when i tight or untight the screw and i can see the gasket behind tb.

@shabbir.1 @Hassan1991

[hasankhurshid29]

vss should also be connected to ecu. check it is connected or not.

If not connected how speedometer is working

[hasankhurshid29]

I have checked the vss harness and it is connected

[hasankhurshid29]

[rajaahmed96]

Remove iacv grip and then check rpm. Also reset the ecu by removing battery terminal for 5 minutes. It should idle at 800rpm.

[Hassan1991]

As said try resetting if doesn't work check the cable it can be tight.
does vss only show error on cng?

[hasankhurshid29]

does vss only show error on cng?

Yes I try disconnecting and there are no errors on cng and petrol

[hasankhurshid29]

Remove iacv grip and then check rpm. Also reset the ecu by removing battery terminal for 5 minutes. It should idle at 800rpm.

The mechanic reset the ecu by disconnecting for few seconds. Maybe it needs to be disconnected for long. What is iacv grip? I removed the iacv harness and rpm still reaches 1400 and cel on.

[rajaahmed96]

Iacv is auto choke which is at back of Intake Manifold. Clean iacv properly and ensure its working freely. Also too much fiddling with idle air screw will damage the throttle body and idle won’t be perfect.

[hasankhurshid29]

Iacv is auto choke which is at back of Intake Manifold. Clean iacv properly

On my car, iacv needs replacement I have already removed it and inspected it. But It can't be reson for high idle as when I disconnect it still the rpm was 1400

[hasankhurshid29]

Which sensors help ecu maintain the idle? @shabbir.1 @rajaahmed96 @Hassan1991

[rajaahmed96]

Iacv and coolant temperature sensor.

[rajaahmed96]

Its better that you buy complete throttle body with all sensors and iacv. This one is in bad state.

[hasankhurshid29]

Its better that you buy complete throttle body with all sensors and iacv. This one is in bad state.

Why complete? Why not buy only iacv?

[Hassan1991]

you can check the iac. when it leaks air it make noise which can be heard if you take air intake off.
don't understand the vss part? no error on cng and petrol then?