[flash]

so, for months now, i've thought my car was rather flat in the mids - i'd step on the gas, and it just didn't seem like it used to be - the problem is that i just don't drive the car enough



then i put in pete's stuff, and while the 5k and up range got noticeably better, the 2k - 4.5k area got worse - this did not make sense to me - i knew that the setup was actually going to give me more in the mids - not less



i had adjusted my fuel pressure back down to where i thought stock was (long story, but for now we'll leave that alone)



i played with the fuel pressure today, and got it happier, but it still doesn't seem right



so, i decided to disconnect the variocam solenoid (that is the one on the valve cover, right?) to see if that was the problem - NO DIFFERENCE! - driving was exactly the same throughout the range and throttle positions



no warning lights ever - the light does work, as i get the warning at startup, and when i engage the parking brake - i did blink test with it plugged in and disconnected - disconnected, i get a 1135, which is hall sensor - plugged in i get a 1235, which says loose connector at hall sensor



i disconnected and played with both the one on top and the one at the back of the distributor - no change



my theory is this:



i know that the Racer X chip achieves a lot of its power via manipulating the timing advance, a lot more than the RS Barn chip does - i suspect that it was masking the non-functioning solenoid or sensor by advancing things enough itself to provide "reasonable" driving condition and performance - when i changed to a chip that did a better job of managing things, and did it with less timing, the symptom popped up as more noticable - this would also seem to explain the fuel pressure changes making a difference



my questions are these:



1. has anyone else disconnected the solenoid and experienced a difference? if so, what was it?



2. is there a test i can do on the solenoid itself? i have not yet removed it



3. if i remove it, are there seals or anything i will need to reinstall it? are there any other complications with removal?



4. why would i not get a warning light with it disconnected?



the good news is that i clearly have a problem, and am really looking forward to how it will drive when corrected

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[flash]

to add to question list:



it seems like less than a simple thing to R&R the hall sensor - the corner of the valve cover looks to be in the way of the retainer screw on the back - is this how it comes out? do i really have to remove the valve cover to remove the hall sensor?



what exactly is it that fails in the sensor? mine "look" perfect - no cracking or brittleness on wires etc - i may well have just a loose connection and certainly i will clean the contacts and try that first



since this popped up, i've got it all apart right now to check the belts anyway, so this isn't really so bad, but i'd like to tackle everything at once

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[flash]

okee dokee



fault codes all gone - seems better, though now my mixture has gone to hell in a hand basket - lol



cleaned connections up, blew everything out while i had belt cover off (belts look perfect - wohoo) - reset system - bingo 1-5



now a fuel gauge and a/f meter and i think i am good to go

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[Greimann]

Some time ago I did some runs with the variocam unplugged and didn't think there was any seat of the pants difference. After researching anything I coud dig up on the function, the only conclusions I could draw was that it is:



- Capable of activating between 1500 and 5500 RPM

- Oil temperature can vary the shift points.

- I think you have to be at WOT (not sure)



There is a test in the manual that you can do to see if the solenoid is working. You apply voltage to the pins and can hear a click. At idle speed, the motor will die because the overlap fudges up the intake charge.



Was thinking of hooking up a telltale light to the circuit to see just when the thing engages. Might be the next project.





On the fuel gauge, I look in PepBoys occasionally for that special fitting that works with my rig job but no dice. They discontinued it.

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[mefforddk]

[quote name='flash' date='Mar 19 2006, 04:16 PM']to add to question list:



it seems like less than a simple thing to R&R the hall sensor - the corner of the valve cover looks to be in the way of the retainer screw on the back - is this how it comes out?  do i really have to remove the valve cover to remove the hall sensor?



what exactly is it that fails in the sensor?  mine "look" perfect - no cracking or brittleness on wires etc - i may well have just a loose connection and certainly i will clean the contacts and try that first



since this popped up, i've got it all apart right now to check the belts anyway, so this isn't really so bad, but i'd like to tackle everything at once

[right][post="17593"]<{POST_SNAPBACK}>[/post][/right][/quote]



flash,



You have to lossen the vavle cover and lift it up to gain access to the top screw holding the hall sensor in place. Pain the the rear.



I just wired up a new hall sensor and either have a bad one or wired it up incorrectly.

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[flash]

dave g - was thinking much the same thing - steve suggested it too



will probably just buy the right gauge all set up - i should have one anyway



dave m - yeah - figured that out - no worries - i think it's fine now - i'll be getting in there anyway to check out the variocam - might just change the sensor anyway



as for any seat of the pants feel, since it's 6 degrees, it should be quite noticable - first drives indicate that it's better - still have fuel pressure and mixture to get right, but it pulls better - no more falling flat on its face - i'll so some connected/disconnected runs tomorrow - tired now - beer thirty



i had a page earilier that had the vw part number for the gauge - now i can't find it

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[flash]

found it - figures - dave posted the number - where does he find that stuff?

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[Greimann]

Had no idea I put that out already.



Part of the secret is to browse the 944 and the 968 manuals. You scroll the pages and download that into the pornographic memory.

Fuel_pressure.pdf Size: 437.84 KB  Downloads: 44

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[flash]

lol - i find that as each year goes by, i forget more and more often where i put things



i think i'll likely snag that gauge tomorrow, unless i can find that adaptor and then build what you did



not sure which A/F gauge i want yet

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[Ryan]

So Flash,



Did you end up having to replace things to fix your problem or were they dirty connections? You never really say.

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[flash]

reread post #3 above



still have to reset fuel though

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[flash]

fuel reset - wow - .4 bar lean - i was clearly monkeying around in there and lost track of where i was - now just a confirmation of functioning variocam, and i'm good to go



it's amazing how sensitive these engines are to changes in timing and fuel mixture - i am now not surprised at all that people have had as many mystery issues as they have - i am now convinced that many of the problems experienced by others are likely due to such things

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