throttle body

**aidy-cdti** · 23rd July 2011, 21:39

cleaned my throttle body earlier today and took the black case off the botttom where the mechanism and circut board is and it was swimming in dirty black oil.
i know this is not meant to be but would that be the reason my car is smoking like a trooper on tickover and acceleration.
Also i have very poor acceleration and i mean very poor. ????

**hebblemarine** · 24th July 2011, 07:27

It could well be m8. If the valve is strangling the engine of air (because it is stuck, or not working), then it would smoke.

If there is a way you can guarantee that valve is open when you run the engine and it runs fine, then that's yer problem!

What is the valve's resting position? Can you get the valve to stay open (say by turning the ignition on, then unplugging the valve)? Reconnect the air inlet pipes (so the MAF sees airflow) and run the engine - how is it?

There is a how 2 on repairing the circuit board, as they have been known to suffer from dry solder joints, but if it got soaked in oil, it may be shagged. If you can demonstrate that then engine runs fine with the valve open, at least you have isolated the problem and can replace or repair the unit.

**aidy-cdti** · 24th July 2011, 22:45

could you tell me the posissions the flap is meant to be in like on idle and acceleration please?
and i think the normal possision is open when the engine is off il check again tomorrow. ****** car.

**roswell** · 24th July 2011, 23:23

The flap is only closed for shut down, it stays closed when the engine is off and opens when the key moves to position 2.

So in short its shut when the engine is off and fully open when running / position 2 of the ignition key.

**aidy-cdti** · 25th July 2011, 11:05

mine is constantly open. even when engine is off.

**felixx** · 25th July 2011, 17:40

Originally Posted by aidy-cdti

mine is constantly open. even when engine is off.

I part cleaned my throttle body yesterday,(took off the boost hose,wiped all the gunge out with a rag and sprayed carb cleaner all over on the inside,and as far down the inlet manifold as I could,and left it for 1/2 an hour,then took it for a run).During the cleaning part,the butterfly valve was defo in the open position,(in line with the manifold and not across it).This was with all the electrics switched off and the key out of the ignition. FELIXX.

**hairy31** · 25th July 2011, 18:37

at the risk of sounding absolutely numb.............where is the throttle body

**GazVXLINE170** · 25th July 2011, 19:18

All diesels are not throttled - reason? If they were throttled like petrols there wouldn't be enough compression to ignite the diesel.

Throttle plates in diesels (aka 'Anti Shudder Plate'/'Shut off Plate'/'Emissions Control Plate') throttles diesels by partially closing over the intake to the manifold - ok like a petrol, BUT this will cause a pressure drop in the manfiold and subsequenltly the cylinders. Compression ignition engines like the good old diesel need pressure in the cylinder to ignite the fuel, which is where the EGR valve comes in. As the plate partially closes over, the pressure difference between the exhaust manifold and inlet manifolds cause the EGR gases to flow into the inlet; meaning the cylinders maintain pressure to ignite the fuel.

Blanking the EGR valve won't affect throttling as the engine will just leave the plate open, well I say that based on people who have blanked the EGR valve and engine hasn't cut out.

Taking the plate off will make the car judder a bit on shut down. Mines has been off for the last 20k, and no problems.

**felixx** · 25th July 2011, 19:19

Originally Posted by hairy31

at the risk of sounding absolutely numb.............where is the throttle body

On a 150 engine,it's the "box" that the large fat boost hose,near the oil filler cap,fit onto.It regulates the amount of air and gas mixture from the EGR valve going into the inlet manifold.They're mixed together in the swirl pots then burned in the engine.Because of the oil vapour in the crank case emissions,which are reintroduced back into the system just before the turbo,and the soot in the exhaust gasses from the EGR valve combining to form a sludge,it gets fouled up,and is a regular item for cleaning in the ongoing battle that the 150 engine vectra owners have in attempting to avoid their inlet manifolds from having a terminal heart attack!!!. FELIXX.

**aidy-cdti** · 25th July 2011, 19:36

so does the buterfly gradualy open the more you put your foot down. Or does it stay fully open no matter how hard you put the accelerator down?? like i said in a previous thread mine was full of oil at the bottom where the pcb and mechanism is so my guess it ******ed and not getting the correct signals.