The Mixture Screw

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Loo-knee

Loo-knee

New Member
Posts
90
Location
Stoke-on-Trent
I was told that under the little disc on the top of the Throttle Body was the tick over screw!! and so like a Fool I listened and played with this allen key head bolt/screw which didn't alter my tick over one bit, but when I took the old girl for MOT he said it was running that rich it was off the scale!!!!!! so do any of you know an easy way of setting the mixture screw back properly? is it all the way down the 3 full turns ??? or something like t)hat?
Any help will be greatly appreciated

I have done the head gaskets the cylinders looked fine, but the heads were warped so had them skimmed, new head gaskets, bolts, plugs etc etc but have a slight miss on the passenger side I think as i am getting a little pop when you stand at the rear of the car, you can hear it through the exhaust.... I am thinking (hoping) it could be a lead so tomorrow I will remove a lead from each plug to see which is the problem, (may check the plugs first though) I had a brilliant spark tester but broke the bloody thing about a month ago :mad: typical or what??

Daz
 
Loo-knee said:
I was told that under the little disc on the top of the Throttle Body was the tick over screw!! and so like a Fool I listened and played with this allen key head bolt/screw which didn't alter my tick over one bit, but when I took the old girl for MOT he said it was running that rich it was off the scale!!!!!! so do any of you know an easy way of setting the mixture screw back properly? is it all the way down the 3 full turns ??? or something like t)hat?
Any help will be greatly appreciated

I have done the head gaskets the cylinders looked fine, but the heads were warped so had them skimmed, new head gaskets, bolts, plugs etc etc but have a slight miss on the passenger side I think as i am getting a little pop when you stand at the rear of the car, you can hear it through the exhaust.... I am thinking (hoping) it could be a lead so tomorrow I will remove a lead from each plug to see which is the problem, (may check the plugs first though) I had a brilliant spark tester but broke the bloody thing about a month ago :mad: typical or what??

Daz
Click to expand...

Why didnt you just get the MOT tester to adjust it whilst it was on the gas tester?
 
Last edited:
v8hotrodboy said:
Why didnt you just get the MOT tester to adjust it whilst it was on the gas tester?
Click to expand...


The honest answer is because, it was when I was driving home it dawned on me that the screw I orginally thought/was told was the idle screw was the Mixture Screw or else I would have done. . .

Thanks for your help though:)
 
Loo-knee said:
Not much help here I'm afraid I aint got a bloody clue which it is :confused: it is an R reg 4.6 if that helps:(
Click to expand...
Ok,its going to be a Gems,you can confirm it by the 4.6 cast into the top of the engine,Bosch would not have that.That screw is not a mixture screw,it is the idle bypass screw - it is used in conjunction with Testbook to set the idle stepper motor to the correct opening.(15-30 steps at idle,engine hot all loads off.)
You have to get rid of the missfire - completely before you have any chance at all of passing an emissions test.See how you go with the plugs and leads,NGK BPR6ES for plugs and genuine,NOT "OEM" Sh--part leads and you have a good chance of it working.
 
eightinavee said:
Ok,its going to be a Gems,you can confirm it by the 4.6 cast into the top of the engine,Bosch would not have that.That screw is not a mixture screw,it is the idle bypass screw - it is used in conjunction with Testbook to set the idle stepper motor to the correct opening.(15-30 steps at idle,engine hot all loads off.)
You have to get rid of the missfire - completely before you have any chance at all of passing an emissions test.See how you go with the plugs and leads,NGK BPR6ES for plugs and genuine,NOT "OEM" Sh--part leads and you have a good chance of it working.
Click to expand...
Last time i failed my MOT it was a 0xygen sensor.
 
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