Any AVCS experts
01 August 2010, 05:26 PM
#1
Any AVCS experts
Trying to get to the bottom of my avcs probs on my car. Bit of background for those that haven't seen my ramblings before. 2002 jdm sti, was rocky at idle all the time, found that the cam belt was fitted wrong (when crank and 3 other cam marks lined up) n/s inlet/avcs cam was one tooth advanced. Sorted that and it's fine when warm but it still rocks the same at idle when you first start it cold, it's exactly the same rocking as before and I'm pretty sure after much messing it's avcs related.
Had a play again today and while I had one of the oil control solenoids out for cleaning I decided to check the plug with a multimeter. With the ignition on (not running) I was getting 0.55 volts through it, but it started going to 0 volts and back up. Wiggled the wiring and it kept coming back, bingo I thought.. Broken wire! Found the dodgy bit in the wiring (ocv wiring is a bit tight under the bracket and it'd broken inside) cut the offending bit out and soldered a new length into the loom, checked it again and had a steady 0.55 volts and not dropping etc when wiggling loom now.
Was quite hopeful it was going to be sorted now but fired it up and again it was rocking away for a while until it sorts itself out! Gutted.
Now, it's got me thinking.. Is there actually supposed to be 0.55 volts to the ocv with ignition on? Maybe it's not supposed to be powered until cam advance is desired?
But looking at how the ocv operates voltage to it shuts off the oil flow? I put power to it when I had it off the car and it shuts the small hole in the end off tight, I'm assuming this stems the flow of oil to the cam wheel?
If this is the case then maybe I should have more than 0.55 volts there when ignition is on?
Can anyone give me a in depth guide on how the different parts of the avcs system work in conjunction with each other? Really struggling to find anything technical on the net about it, it would help to know exactly how it works to point me in the right direction. At the moment I'm not sure if the ocv's let oil flow at idle, should be shut off and whether power is stemming flow to the cam wheel or letting it go, what tells the ocv's what voltage to see etc etc
Doing me head in now, I hardly get any time to try and sort it these days and I thought the broken wire was the answer. To top it off ecuexplorer has stopped working and I cant view any live data anymore for some reason ( google is full of instability probes with ecuexplorer.
Had a play again today and while I had one of the oil control solenoids out for cleaning I decided to check the plug with a multimeter. With the ignition on (not running) I was getting 0.55 volts through it, but it started going to 0 volts and back up. Wiggled the wiring and it kept coming back, bingo I thought.. Broken wire! Found the dodgy bit in the wiring (ocv wiring is a bit tight under the bracket and it'd broken inside) cut the offending bit out and soldered a new length into the loom, checked it again and had a steady 0.55 volts and not dropping etc when wiggling loom now.
Was quite hopeful it was going to be sorted now but fired it up and again it was rocking away for a while until it sorts itself out! Gutted.
Now, it's got me thinking.. Is there actually supposed to be 0.55 volts to the ocv with ignition on? Maybe it's not supposed to be powered until cam advance is desired?
But looking at how the ocv operates voltage to it shuts off the oil flow? I put power to it when I had it off the car and it shuts the small hole in the end off tight, I'm assuming this stems the flow of oil to the cam wheel?
If this is the case then maybe I should have more than 0.55 volts there when ignition is on?
Can anyone give me a in depth guide on how the different parts of the avcs system work in conjunction with each other? Really struggling to find anything technical on the net about it, it would help to know exactly how it works to point me in the right direction. At the moment I'm not sure if the ocv's let oil flow at idle, should be shut off and whether power is stemming flow to the cam wheel or letting it go, what tells the ocv's what voltage to see etc etc
Doing me head in now, I hardly get any time to try and sort it these days and I thought the broken wire was the answer. To top it off ecuexplorer has stopped working and I cant view any live data anymore for some reason ( google is full of instability probes with ecuexplorer.
Last edited by jameswrx; 01 August 2010 at 05:28 PM.
01 August 2010, 11:37 PM
#2
Found some info on nasioc
Under 70C water temp, the system is not active. The second 70C is reached the solenoids are clicked forward and oil pressure arrives at the diaphrams. The cams move and the movement is read by the cam sensors. An alignment procedure occures at that point. Duty cycle can be different from left to right but many times its the same....
Quite interesting in that mine behaves itself when this point is reached.
Maybe this alignment procedure sorts it out but for some reason it's back to rocky when it's stood for long enough for the water temp to dip below 70'c
Apparently avcs takes info from coolant sensor, tps, air flow and camshaft position.
I've recently fitted a new coolant sensor so can't be that.
Wish I could get ecuexplorer working as I'd like to watch live data from cold start and see what happens when it hits 70'c
Obviously with avcs not being active until 70'c I've got some sort of problem which either means I've got pressure getting through and advancing the cam or just a solenoid being out of alignment after not being used which could be the same thing I suppose.
Under 70C water temp, the system is not active. The second 70C is reached the solenoids are clicked forward and oil pressure arrives at the diaphrams. The cams move and the movement is read by the cam sensors. An alignment procedure occures at that point. Duty cycle can be different from left to right but many times its the same....
Quite interesting in that mine behaves itself when this point is reached.
Maybe this alignment procedure sorts it out but for some reason it's back to rocky when it's stood for long enough for the water temp to dip below 70'c
Apparently avcs takes info from coolant sensor, tps, air flow and camshaft position.
I've recently fitted a new coolant sensor so can't be that.
Wish I could get ecuexplorer working as I'd like to watch live data from cold start and see what happens when it hits 70'c
Obviously with avcs not being active until 70'c I've got some sort of problem which either means I've got pressure getting through and advancing the cam or just a solenoid being out of alignment after not being used which could be the same thing I suppose.
02 August 2010, 06:00 AM
#3
Scooby Regular
Found some info on nasioc
Under 70C water temp, the system is not active. The second 70C is reached the solenoids are clicked forward and oil pressure arrives at the diaphrams. The cams move and the movement is read by the cam sensors. An alignment procedure occures at that point. Duty cycle can be different from left to right but many times its the same....
Quite interesting in that mine behaves itself when this point is reached.
Maybe this alignment procedure sorts it out but for some reason it's back to rocky when it's stood for long enough for the water temp to dip below 70'c
Apparently avcs takes info from coolant sensor, tps, air flow and camshaft position.
I've recently fitted a new coolant sensor so can't be that.
Wish I could get ecuexplorer working as I'd like to watch live data from cold start and see what happens when it hits 70'c
Obviously with avcs not being active until 70'c I've got some sort of problem which either means I've got pressure getting through and advancing the cam or just a solenoid being out of alignment after not being used which could be the same thing I suppose.
Under 70C water temp, the system is not active. The second 70C is reached the solenoids are clicked forward and oil pressure arrives at the diaphrams. The cams move and the movement is read by the cam sensors. An alignment procedure occures at that point. Duty cycle can be different from left to right but many times its the same....
Quite interesting in that mine behaves itself when this point is reached.
Maybe this alignment procedure sorts it out but for some reason it's back to rocky when it's stood for long enough for the water temp to dip below 70'c
Apparently avcs takes info from coolant sensor, tps, air flow and camshaft position.
I've recently fitted a new coolant sensor so can't be that.
Wish I could get ecuexplorer working as I'd like to watch live data from cold start and see what happens when it hits 70'c
Obviously with avcs not being active until 70'c I've got some sort of problem which either means I've got pressure getting through and advancing the cam or just a solenoid being out of alignment after not being used which could be the same thing I suppose.
02 August 2010, 06:50 AM
#4
Well it used to rock exactly the same as this when warm (before I fitted the cambelt correctly) and avcs was 4-5 deg advanced on n/s when warm. I've never tested it on my laptop cold because since I sorted the cambelt ecuexplorer hasn't worked.
My mrs is off for a week so I should have 5 mins after work some time to get ecuexplorer working and try it from cold.
My mrs is off for a week so I should have 5 mins after work some time to get ecuexplorer working and try it from cold.
02 August 2010, 06:54 AM
#5
Scooby Regular
Well it used to rock exactly the same as this when warm (before I fitted the cambelt correctly) and avcs was 4-5 deg advanced on n/s when warm. I've never tested it on my laptop cold because since I sorted the cambelt ecuexplorer hasn't worked.
My mrs is off for a week so I should have 5 mins after work some time to get ecuexplorer working and try it from cold.
My mrs is off for a week so I should have 5 mins after work some time to get ecuexplorer working and try it from cold.
)
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02 August 2010, 09:53 AM
#8
I noticed something similar to this a few weeks back when i changed my belt, plugs and air filter. It seems to rock a little more when the engine is idling but only very slightly.
Everything still seems to be OK but i feel a trip to a specialist just to get it checked over would be a good idea
Everything still seems to be OK but i feel a trip to a specialist just to get it checked over would be a good idea
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