GolfGTIforum.co.uk
Model specific boards => Golf mk2 => Topic started by: cняis on 02 April 2007, 20:31
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Hi!
Am i right in thinking that the screw on the front of my throttle body (brassy coloured) is purely the idle screw or does this adjust the CO too?
I ask this because after my (useless) garage tried setting my car up properly, it was idling too high (1000-1200 rpm when warm). i adjusted this screw so it sits at about 850 rpm, but my MPG has increased from average 34 to 42 over the 5 mile trip to work! :laugh:
Anyway it seem to run a bit smoother so im happy :cool:
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i believe the screw ur on abt is just idle
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The idle adjustment screw is a recessed screw on the throttle body. You need a very small screw driver to adjust it. If you have used a spanner and screw driver to adjust what you thought was the idle screw, then you got it wrong and thrown out the throttle stop and microswitch setting. The CO is adjusted on the Mas Air Flow (MAF) sensor on your air box.
There is a thread in the maintenance section on how to set this lot up. Print it out and go to a noteworthy garage and say, ¨do this please!!!¨¨ :smiley:
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i adjusted the recessed screw, so all's ok - no worry of "throwing out the throttle stop and microswitch setting" :smiley:
its just odd that after adjusting the idle, the car now returns better MPG... :laugh:
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Sounds as if the ´useless garage´ didn´t do a bad job after all then. Just didn´t set the idle correctly.
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42 mpg on a 8v digi? I never knew this was possible! :rolleyes: on the other hand could the fueling be too lean? is there good pull through the gears? any over heating? pinking? if so need to get that sorted, if not then very nice! :wink:
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yes its pinking slightly, which is why it went to the garage in the first place. but it was pinking even before i adjusted the idle (i.e. at 34 mpg average). 2 garages have looked at it so far and havent come up with an answer!! :angry:
it doesnt over heat or anything, and only pinks when under heavy load (i.e. full throttle)
the last garage that looked at it couldnt even find any timing marks on the gearbox (even took the cap off), so "set the timing by ear" :undecided: but they didnt charge me just in case it was wrong!
im half tempted to take it to a tuning specialist who might know their stuff. fed up is an understatement!
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I would get it done properly if I were you. Pinking is bad news and puts a hell of a strain on the engine. Pinking is spontanious combustion and not a steady burning of the fuel. It´s caused by peak cylinder pressure being reached too soon. This is usually caused by badly adjusted timing or too lean a mixture. Or the wrong grade of fuel being used. (should be 98, not 95.)Either way, the burn heat in the cylinders is excessive, although this is not reflected by the engine temp.
Bosche agents, I have found usually know what they are doing, even on a digifant system. The didgifant system is basically an electronic version of the Bosche k-jetronic, with a few other differences.
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if they set it up by ear thats why its pinking, it has to be set to exactly 6 degrees BTDC @ 2.25k rpm with the blue sender disconnected, as per my FAQ. Did the garage know they have to remove the large round bung screwed into the top of the gearbox housing? It's possible the top end is 180 degrees off from the bottom end too, which would explain the lack of timing marks...
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if they set it up by ear thats why its pinking, it has to be set to exactly 6 degrees BTDC @ 2.25k rpm with the blue sender disconnected, as per my FAQ. Did the garage know they have to remove the large round bung screwed into the top of the gearbox housing? It's possible the top end is 180 degrees off from the bottom end too, which would explain the lack of timing marks...
They removed the bung but could find no marks, so sounds like its all 180 degrees out... what do i do?? :shocked:
oh and i always use 98 Ron
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print off rubj's faq and take the car back to em ! :smiley:
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Will do, and i shall remove the chip thats in it too...
http://www.golfgtiforum.co.uk/index.php?topic=46972.0
i'm sure it all stems from this.
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I dont think the chip will affect anything, I've got one and it works great!
To check if your timing is indeed 180 degrees out, remove all the spark plugs and rotate the engine by hand with a socket on the cam sproket bolt. Watch the timing check hole untill you find the timing marks, theres a good pic in my FAQ of what you are looking for :)
It may be that the 6 degree BTDC mark is missing, so keep an eye open for the small punch mark. It may be hard to spot, so at the same time if you shine a torch down sparky hole #1 and watch for the cylinder rising to the top of the bore. This will happen twice for every rotation of the cam & dizzy :)
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thanks for all your help, i shall go to a competant garage (3rd time lucky) with all the info.
by the way, would the CO adjustment have anything to do with pinking? what actually happens if the CO is not correct?
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If the CO is not right,then you could fail the emissions at the next MOT with the engine running too rich, and you will have high fuel consumption. If you go the other way, then you can get pinking, possibly shortening engine life due to hot burning temps. Your emissions will be low as will your fuel consumtion.
You need the fuel air mixture to be within certain tolerances to run nicely. (About 14:1 air fuel ratio give or take a couple on the air). This is called the stoitiometric mixture! Or ideal burn ratio.
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Get the CO, idle speed & ign timing set up properly as per my FAQ, then let us know how you get on!
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Funnily enough, a mate suggested i stop using 98 RON and stick some 95 RON in... its stopped pinking :shocked:
whats going on??
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looks like you need to re-set it for 98 ron petrol, though in theaory 98 ron should be LESS likely to pink :undecided:
Sound like your car needs some rubjonny lovin :cool:
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Sound like your car needs some rubjonny lovin :cool:
Can i get some of that for mine please!? :sad:
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Ive just taken it for a 30 mile sunday drive and... it still "pinks". it needs me to tke it to a good garage!
although, pardon my ignorance, but i thought pinking also resulted in stuttering (as the cylinder would not fire properly) and excessive engine (oil) temperature? I have experienced neither! :undecided: