Helen car has been serviced recently and ever since the service it had developed a hesitation at low speeds especially in second gear. It annoyed the hell out of me, to Helen it didn't matter she did not mind it one bit. Well I wasn't going to accept it.
A brief introduction regarding Exhaust Gas Recirculation (EGR) System Diagram.
The EGR system reduces oxides of nitrogen (NOx) emissions by recirculating exhaust gas through the EGR valve and the intake manifold into the combustion chambers. The ECU memory includes the ideal EGR valve position for varying operating conditions.
The EGR valve position sensor detects the amount of EGR valve lift and sends it to the ECU. The ECU then compares it with the ideal lift in its memory (based on signals sent from other sensors). If there is any difference between the two, the ECU cuts current to the EGR valve. ERG reduces pumping losses in the engine which is ideal for complete combustion. Removal or blockage to the ERG function increases pumping losses.
So today I had a enough and wanted to check out the throttle body and ERG plate condition
First get the remove the intake manifold cover.
You will then see the plate remove all bolts and remove the pipe to the top of the plate.
Remove the pipe to the plate and remove all the bolts give the plate a tap around to which helps in easy removal without damaging the gasket.
Removal of the Plate and the gasket
As a best practice you should replace the gasket but this seemed in really good shape and it wasn't damaged when removed. If you plan to do this DIY make sure you pre order another gasket prior working on the car.
The car has been run on VPower since 2005 and wasn't to surprised not to find layers of carbon build up. There seems nothing out of the ordinary.
Next step is to use IPA to clean the plates and gasket.
I used Mircofiber cloths to clean the gasket and manifold , I left the plate immersed in IPA for two hours and agitating it every 15 minutes see the colour change to jet black
There was not a lot of carbon build up so no pictures of heap of carbon The two microfiber cloth were really dirty.
This was the end result:
The Thottle body
Remove the air duct hose from the filter and disconnect the intake air temperature (IAT) sensor connector (A). Remove the vacuum hose (B) and breather pipe (C), then remove the intake air duct (D).
You can see a dark ring of carbon around the circumference of the flap and when half open you could see a ring of carbon the throttle body internals .
A through clean and left with perfectly clean internals and flap.
It was a simple case of refitting everything back in reversal and then carry out an idle learn process.
Idle Learn Process for the K20A Engine
Since I have the HIM \HDS Connect the HDS to the data link connector (DLC)
Make sure all electrical items (A/C, audio, rear window defogger, lights, etc.,) are off.
Reset the ECU with the HDS.
Turn the ignition switch ON (II), and wait for 2 seconds.
Start the engine, and hold it at 3,000 RPM (min) without load (in neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 90°C (194°F). You can view this in the HDS data logs
Let the engine idle for about 5 minutes with the throttle fully closed. NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.
Then disconnect the negative cable from the battery, and wait for 10 seconds.
Connect the negative cable then start the engine.
Let the engine idle for about 5 minutes with the throttle fully closed.
Set the time on the clock again on the car.
That's it guys the car run perfectly. Hope this DIY helps petrol owners suffering the same symptoms.