hey guys had my G40 a few weeks now and it seems it doesnt pull as hard as it did in the first few days of having it! i am currently running on ordinary unleaded could that have something to do with it?
also my car idles pretty high sometimes and i read some were about removing the idle control sensor and giving it a clean may stop this! but then iv also been told it could be the blue temp sensor? can some one send me some pics of were the idle control sensor and blue temp sensor are so i can try them both!
all help will be really appreciated!
cheers
Ross
the idle control valve is under the inlet manifold behind the head. pipe going in either side and a plug.
The blue temp sensor is on the ride hand side of the head as you look at the engine. 2 plugs - 1 black 1 blue. New sonsors roughly £7 from gsf.
does that mean removing the inlet manifold to get to the sensor?
Easier if you do although its still possible to get at with the inlet in place but it can be fiddly.
its running pretty rich tooo any ideas with that?
probably blue CTS again, replace them first as fairly cheap and worth doing anyway then see whats going on. Also, as has been said, check ISV connector clean and ISV itself working ok (carb cleaner) and check CO Pot set to 550ohms.
get a blue temp sensor from vag mate - the GSF ones are shit and known for being a common failure. i bought one once just to get my car running and it didnt even fit in the coolent housing!!! CHEAP SHITE!
also - check for vacuum leaks- you may have created one after giving it a lot of beans
GSF blue temp sensors really that shite? I got mine from gsf and it fit ok. Dunno if its dodgy though!
they just dont last mate!
they are really are not very good at all and im sure a lot of people will back me up on this.
If its idling high have you tried adjusting the idle screw on the throttle body?
i havnt tried the idle screw on the throttle body no! but i dont think it will be that as it doesnt always do it just some time when i pull up at a junction or something!
Quote from: youngprodigys on May 05, 2010, 07:24:30 PM
get a blue temp sensor from vag mate - the GSF ones are shit and known for being a common failure. i bought one once just to get my car running and it didnt even fit in the coolent housing!!! CHEAP SHITE!
also - check for vacuum leaks- you may have created one after giving it a lot of beans
were would i find vacuum leaks? ive just also noticed ive got a bit of an oil leak!
where abouts the oil coming from? top or bottom
Quote from: grayg40 on May 06, 2010, 10:10:56 AM
where abouts the oil coming from? top or bottom
bottom from the left of the oil filter it looks like but havent had chance to have a proper look need to get it up on axel stands!
oil leak fixed! replaced blue temp sensor, still idles high every now and then! went to my local vw dealers today to get an idle control valve sensor n they wasnt sure what i was talking about so have been asked to go in so they can have a look and see where it is! any one give me the correct term for this idle control valve sensor? or a part number?
cheers
Ross
it's called an auxiliary air valve usually, people often call it an idle stabilisation valve but that's not really what it is.
Quote from: hayesey on May 18, 2010, 09:02:54 PM
it's called an auxiliary air valve usually, people often call it an idle stabilisation valve but that's not really what it is.
thanks for that mate! iv just been back to my local vw dealers having found the part number and the isv is not far off £100 cos they have to be made to order! is that right?
cheers
Ross
yeah they're not cheap, people usually just clean them out by removing them and soaking in petrol for a bit.
I'm pretty sure the auxiliary air valve thing only works when the engine is cold/warming up. I could completely clamp the hose from the valve to manifold shut on my G40 and it had no affect on idle. I would just try cleaning it out first. It's actually the ECU that stabilises the idle by adjusting the timing. If you have the base timing set wrong or too much/too little air going in with the idle trim screw on the throttle body it will tend to have an unstable idle. You can't just change the settings as you are constantly fighting the ECU. You need to disconnect the blue temperature sensor with the car nicely warmed up (only disconnect this when the engine is running to avoid logging faults). This puts ithe ECU into service set mode. Then adjust base timing and idle trim screw as required. Then put back blue temp sensor and ECU will take over again.
yeah it is supposed to only work when warming up but when they get gummed up or just fail they can open at any time causing a dodgy idle because there's just too much air getting in to idle properly at normal running temps.
Quote from: G40supercharged on May 19, 2010, 12:22:36 PM
I'm pretty sure the auxiliary air valve thing only works when the engine is cold/warming up. I could completely clamp the hose from the valve to manifold shut on my G40 and it had no affect on idle. I would just try cleaning it out first. It's actually the ECU that stabilises the idle by adjusting the timing. If you have the base timing set wrong or too much/too little air going in with the idle trim screw on the throttle body it will tend to have an unstable idle. You can't just change the settings as you are constantly fighting the ECU. You need to disconnect the blue temperature sensor with the car nicely warmed up (only disconnect this when the engine is running to avoid logging faults). This puts ithe ECU into service set mode. Then adjust base timing and idle trim screw as required. Then put back blue temp sensor and ECU will take over again.
ive replaced the blue temp sensor! if i do what you say about removing the blue temp sensor will the car start to idle higher?
cheers
Ross
By disconnecting the blue temperature sensor I mean just take the connector off. The blue temperature sensor normally has a fairly low resistance. When you disconnect it with the engine running the ECU sees an open circuit (very high resistance) and that tells it to go into service mode. (If you start the car with it already disconnected the ECU will just think the sensor is broken.) The idle speed may go up or down when the sensor is disconnected; the point is that the ECU will no longer be trying to adjust the idle speed, so the idle should stay at the same revs. You can then adjust it as you like using the idle screw on the throttle body (something like 1000rpm would be OK). You have to set the timing like this as well, otherwise the ECU is constantly adjusting it.
So: engine running and fully warm, disconnect blue sensor, set idle to factory spec with timing strobe, set idle speed to factory spec, reconnect blue sensor. It should then be nice and stable at factory idle speed (which is programmed into the ECU).
nice one cheers matey!
I've just re-read that and it should be "set timing to factory spec with timing strobe" rather than "set idle to factory spec with timing strobe"
Quote from: G40supercharged on May 21, 2010, 12:12:14 PM
I've just re-read that and it should be "set timing to factory spec with timing strobe" rather than "set idle to factory spec with timing strobe"
whats the timing strobe?
Quote from: g40Ross on May 21, 2010, 02:31:40 PM
whats the timing strobe?
Engine timing light. It's connected to no.1 plug lead, so it flashes each time that plug sparks. So with the engine running, when the light is aimed at the pullley the timing mark on the pulley appears to be stationary. The distributor is then adjusted until the mark on the pulley lines up with the pointer on the engine. The timing marks are easier to see if you put something white on them, like tippex or chalk. But make sure the mechanical timing is right first.