What fault code/codes came up?diagnostics say i have a faulty ICV but dont mention the EGR valve
when im driving along at 40mph in 5th or 30mph in 5th sometimes the car start violently jerking until i dip my clutch or put throttle to the floor
this doesent make sense for an IDLE valve?
well ive done a half clean of my throttle body which seems to have made it worse, but the top of it now is clean and the bottom i can see is filthy stillthat is the one of the same problems im having on my vauxhall tigra 1.4 16v ecotec. could it not be the throttle body?
well i cleaned like i said, half my throttle body and it doesent rev up and down as much, it just stays at about 1200 when i come to a stop and lowers to 900 after a while, im getting a new idle valve delivered tommorow, if its still dodgy im going to get a brush and fully clean the throttle bodyim having problems like car cutting off on traffic lights and to start it back, you have to have your foot on the gas pedal, sometimes also problems like the revvs shoot up to about 3000 when im stopped at traffic lights with foot on the clutch. however i do not have any engine menagement lights coming on?
You would be far better off taking it off completely, but be careful of the paper gasket where it joins the engine. Get yourself an old toothbrush, some cocktail sticks, and a soft cloth. Once removed give it a thorough scrubbing, taking care to clean the little holes above and below the butterfly. The ICV is connected to this as well. This can be removed and sometimes dismantled and cleaned. When I did mine I filled it with thinners and shook it, emptied it and re-filled shook it. Repeated untill it all came out clear. When doing the throttle body I would also make sure the butterfly is spotless. Take extra care around the edge, and in the bore of the throttle body where it sits when closed. Any gunk in there will make it stick and also stop it from closing properly allowing more air in leading to high revving when at idle. If you look carefully at the inside of the throttle body you will see a couple of little holes. These are the inlet and outlet of the ICV. They are about 2-3mm diameter. If they are full of gunk then no air will be allowed into the engine causing your car to stall at idle. Use the cocktail sticks to clean these out. The result you are looking for it a brand new looking piece of kit when you go to put it back on. I spent ages cleaning it inside and out while watching a film.
Just checked on Autodata 2 for OBD fault code 0505.p0505
and crankshaft sensor has come up within the past 2 weeks but its been jerking for ages and the sensor only just come up as a fault so i dont think its that
ISC Valve = Idle Control Valve (ICV)Just checked on Autodata 2 for OBD fault code 0505.
Came up with:-
Idle Speed Control (ISC) System.
Wiring, ISC Actuator/ ISC valve, throttle motor, throttle valve tight sticking. ECM.
ISC Valve = Idle Control Valve (ICV)
Throttle Valve = Big butterfly that opens and shuts when pushing the acelerator.
As I said its probaly all gunked up and not opening and shutting allowing air through when the throttle is shut. This will starve the engine of air and stall it ... or as you go to pull away and the throttle position sensor tells the ECU to close the ICV but because its stuck it throws a wobbly and flags up a warning The ECU is doing what its supposed to do. Take it off and clean it, or replace it. Either way you still need to get that throttle body cleaned to perfection as the system all works together to ensure it runs smoothly. By the way .. even if you replace the ICV with a new one you need to clear the holes above and below the throttle butterfly or you will still have issues. Even if the ICV moves freely as its supposed to do no air will get through it due to the blockage and the car will stall as soon as you take your foot off the gas.
Does it look like this :
or like this :
The first is an all in one plastic ICV jobby. Sorry for some misleading but its a sealed unit as far as I know. It just unscrews from the throttle body. Take it off and clean out any debris you can find. The other unit is the Throttle position sensor. This again is sealed but doesn't need to come off. You will have to look for any airways that go in and out of the throttle and clean them where the plug on the back of the ICV sits. Please be careful and don't get any thinners/solvents on any plastic or it will melt. The ICV will pull and push the metal plug on the back to open and close the airway. Take your one off and wipe it clean with a rag it may still work, you can always swap it over later by just unscrewing the two bolts that hold it on.
ive just cleaned my throttle body again this time using a brush to clean it, i dont know if its any better reallyI would personally take it off buddy. You will be able to give it a good scrub down till its shiny smooth, which will give less chance of dirt build-up in the future. You can just spray carb cleaner down there but it won't clean it up any way as good as scrubbing, and you will find that the problem will either not go away, or return very quickly. As I said the breather holes for the ICV are very small (2-3mm) and you could really do with making sure they are spotless. When it says partially drain the coolant its a bit misleading. You won't lose more than half a pint or so. Wait until the engine is cold so the coolant is no longer under presuure. Undo the expansion cap and release any residual pressure. Put it back on again. take off each hose to the throttle body and plug it with a rag, bolt, or clamp it. When I did mine I had a little dribble for a few secs and then nothing. Remove the throttle body as described earlier, then clean. Any air that gets in there will bleed itself out of the system easily, just run until warm topping up your coolant if necessary.
Any carb cleaner that gets in your engine will burn off rapidly, you will get an increase in revs as it does. Don't worry about this, and it goes in seconds with no damage done. I would be reluctant to spray anything on the MAF, but other people do with no worries.