Author Topic: Cam Shaft Sensor  (Read 8513 times)

Offline VWstevo

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Cam Shaft Sensor
« on: 11 March 2010, 00:13 »
Hi again.

Does the golf gti mk3 have a cam shaft sensor and if so where is it. I was told it doesn't have one and I have been told it does!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! lol.

Offline Ess_Three

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Re: Cam Shaft Sensor
« Reply #1 on: 11 March 2010, 05:43 »
Hi again.

Does the golf gti mk3 have a cam shaft sensor and if so where is it. I was told it doesn't have one and I have been told it does!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! lol.

8v or 16v?

16v has a cam position sensor in the dizzy, to allow the ECU to know where the cams are to allow sequential injection.

Maybe the 8v has one in the dizzy too.

Hall effect sensor, IIRC.

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Offline bmw156

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Re: Cam Shaft Sensor
« Reply #2 on: 11 March 2010, 07:20 »
i cant see a need for a cam sensor, yeh in a 16v but not in an 8v. if it has a crank sensor, then it would tell the ecu where the crank is at, and from that the ECU should know the cam will be at, because its joing to the cambelt etc.

saying that the crank spins twice to the cams one. hmmm

Offline Ess_Three

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Re: Cam Shaft Sensor
« Reply #3 on: 11 March 2010, 07:28 »
i cant see a need for a cam sensor, yeh in a 16v but not in an 8v. if it has a crank sensor, then it would tell the ecu where the crank is at, and from that the ECU should know the cam will be at, because its joing to the cambelt etc.

saying that the crank spins twice to the cams one. hmmm

Bingo!
That's why you need one...to tell the ECU when the cam is lined up on the inlet stroke of the cycle, so it can inject fuel sequentially to each cylinder in turn.
Not required in a batch fired injection system.

I doubt an 8v has one to be honest, as the dizzy is driven by the intermediate shaft, off the crank...not direct from the cam.

VR6 has one mounted in the head, 16v has one mounted in the dizzy...8v I doubt has one at all, but may be wrong.

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Offline rubjonny

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Re: Cam Shaft Sensor
« Reply #4 on: 11 March 2010, 10:05 »
all 8vs have the equivilant of the cam position sensor, in the distributor. the only difference between the 8v, 16v & vr6 is where the dizzy is positioned, they are still matched to the cam position. Some VR6 dont even have a dizzy, on these the sensor is screwed direct to the side of the head and it reads a timing wheel on cam direct.

cars with a crank sensor i.e early 8v, 16v abf & vr6 has the cam position sensor locked in place. early 8v and mk2 16v have an adjustible dizzy so you can dial in the advance. crank sensor equipped cars do not even need the cam position sensor to run, if unplugged it just reverts to batch fire mode. obviously run better with cam sensor plugged in ;)
« Last Edit: 11 March 2010, 10:07 by rubjonny »
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Offline VWstevo

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Re: Cam Shaft Sensor
« Reply #5 on: 11 March 2010, 10:42 »
all 8vs have the equivilant of the cam position sensor, in the distributor. the only difference between the 8v, 16v & vr6 is where the dizzy is positioned, they are still matched to the cam position. Some VR6 dont even have a dizzy, on these the sensor is screwed direct to the side of the head and it reads a timing wheel on cam direct.

cars with a crank sensor i.e early 8v, 16v abf & vr6 has the cam position sensor locked in place. early 8v and mk2 16v have an adjustible dizzy so you can dial in the advance. crank sensor equipped cars do not even need the cam position sensor to run, if unplugged it just reverts to batch fire mode. obviously run better with cam sensor plugged in ;)

Thanks guy, just that i took it to some suppose to be a VW specialist and he put it on the computer and he told me it cae up with the cam shaft sensor and the lamba sensor. I was told that my 8v doesn't have a ca sensor. I had a new dizzy fitted about 8 months ago and i think it was fitted a tooth out as it bottoms out at 5000 rpm.

Offline axewielder

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Re: Cam Shaft Sensor
« Reply #6 on: 11 March 2010, 12:52 »
Sounds like classictiming issue, just get everything lined up+ checked incl, cam shaft + dizzy

Offline rubjonny

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Re: Cam Shaft Sensor
« Reply #7 on: 11 March 2010, 18:51 »
yeah agreed, sounds like the rotor arm on the dizzy just needs lining up to the mark when engine is at tdc.  recon that vw specialist needs to do a little more research on 8vs ;)
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Offline VWstevo

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Re: Cam Shaft Sensor
« Reply #8 on: 12 March 2010, 19:29 »
yeah agreed, sounds like the rotor arm on the dizzy just needs lining up to the mark when engine is at tdc.  recon that vw specialist needs to do a little more research on 8vs ;)

Thanks guys and yeh Jonny i agree, i just think he couldn't be ar*ed really mate. I just need to find someone who can be bothered and it will need the timing doing manually as can not find the timing mark, found it on the wheel but not the arrow that it lines up with. So it will have to all be done from scratch i think to get the true timing marks lined up and the dizzy needs taking out I think and moving 1 notch. My mate put it on the timing gun other day we could find the mark on the fly wheel but not on the plastic so when we turned the dizzy the timing mark did not move, he said the timing was out by 2 degrees is this enough to cause the bottoming out at 5000 rpm.

Offline rubjonny

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Re: Cam Shaft Sensor
« Reply #9 on: 12 March 2010, 23:46 »
with these you dont use a timing gun at all!
set the cam and crank to tdc, then pop dizzy cap off. look carefully at the outer riung of the dizzy housing and you'll find a faint notch, there is a cutout in the plastic dust cover for this to show thru. line the rotor arm to the notch, and thats all there is to it!
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