Engine Performance problem
2008 Daihatsu Hyjet 4 cyl Four Wheel Drive Manual 30000 miles
I have Piaggio porter with daihatsu engine 1.3 V 16V efi (from daihatsu hijet). The problem is because when I start the engine first time it works with non-stabile idles for first 10-15 seconds-after that it works normaly. TPS is changed (it wasn't work well), Vacum switch valve (VSV idle up) works when is jumped at 12V well and have correct values according to manual, inlet manifold is cleaned, vacum pipes are checked.I have 12 V (13, 3 aprox) on the connector for the VSV when the engine is running at idle speed. It happens only in the morning when I first time start the engine. After that when I start the engine again it works ok. There is no lossing of power or any other symptoms that I noticed except that - unstabile rpm at first start in the morning
I have the same problem with my daihatsu.
If you leave the vent fan on the engine will start first go.
This causes the VSV to open and allow some air to bypass the throttle valve. The only other time the VSV opens is when the thermo fan is operating. Regards Felix