datsun_1600

OK - So I took the car and G-Sensor out for a road test last night. It ran almost fine for the for 30mins then when I was out of city limits and was able to give it a bit of stick I noticed the 4WD split gauge ramped up very quickly to 50%. Then when I did a launch from 1st gear it triggered an error code. I played a little with the two new pots to help eliminate this but as it was dark and I was in a rush I didn't the adjustments fine tuned. Is summary, it seems to be very close to working, but needs some fine tuning - which I most likely will not get done till after March 24th due to wedding stuff... Anyway - looks like it should be fixable! Jeff

So long story short James sent me his G- Sensor to have a look at. Thought I'd document the attempted fix attempt here... First inspection showed that the electrolytic caps had died and leaked acid all over the bottom of the PCB. (Hopefully I get the pics in order here) You can see the black pads and discolouration around the caps and IC's where the acid has leaked in this pic.... (Pic 1) So time for some cleaning.... This is what I normally use.... (Pic 2) It will get most of the crap off – but there will still be a bit left in the joints (Pic 3) After a good clean I resoldered all the joints that were corroded. As the joint is re-soldered the black acid crap from the caps will come out of the joint. So the process goes – solder – clean – solder again – clean... After all this I ran a test and found the two of the three outputs were now working great and could be adjusted via the factory pots to 2.5v– the other one was...well...way low (0.233v). I took the G-sensor off the mount and moved it around and observed the voltage – I could see that is was moving – meaning that the pendulum and thus the g-sensor was somewhat working. The next step is to remove two resistors and replace them with pots to give us a bit more room for voltage adjustments. This can be seen in the last pic (Pic 4) After some tweaking of these two added pots and the factory pots we now have 2.5volts on all three outputs.... Next comes the testing. I fired the car up and all the dash lights went off, then drove it backwards and forwards a few times in the driveway – all good. The next step is to take if for a road test... but unfortunately I've run out of time and have to get some work done. I'll hopefully have a crack at it later tonight.... If it all works then the PCB just needs a good clean and some hot glue to hold down the components added... The reason one of the outputs was low seems to be because the pendulum arm is slightly bent (crash maybe) or perhaps the hall effect sensors are on the way out.... Another interesting point is that it ALWAYS seems to be output "2" that is bad.... Sorry for the bad English – wrote this really really quick! Jeff

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Not so much Skyline related, but I've been hunting for a clean (non rusty and no major dints) Datsun Stanza SSS. I am in the process of restoring mine. I've been advertising on Gumtree for quite awhile, nothing yet.... If you hear of any around in SA or Vic I'd really appreciate it.... I guess even if it's not a SSS I would be interested if the body was good enough... My add on Gumtree: http://www.gumtree.com.au/s-ad/seaford/cars/datsun-nissan-stanza-sss-wanted/347000071 Thanks! Jeff

Hey Mate, that's great news. Depends on which pot. I had one of my pots sitting at 2.4 volts for ages and didn't notice much difference. One thing that will happen if it's running right on the edge is that you might see the fwd bias indicator flicker (ie just to say 1~2%) when you wouldn't expect it. In the end if I was driving up a hill it was enough to trigger the 4wd system... I made another mod not listed on this forum to fix this. If you want to change out a resistor to fix your 2.4v issue (ie can't get the right voltage with the factory pots) just post here and i'll do another write up and post pics. Jeff

I think that looks like a neat product - but I wouldn't believe this part "When cornering and you have broken traction, the stock G sensor would delay in sending this information" In reality, even though the stock G-Sensor is old, it works via old school analogue electronics (meaning it has no way to "delay" anything!!! - there is almost zero "delay".) The only thing that I can think of is the filtering technique: In the original Nissan G-Sensor it uses silicon fluid (thick goo) to slow down the movement of the sensor arms to filter out car vibration, slight jerks etc. I'm guessing this product uses a digital filter to do the same thing, thus allowing the ability to really fine tune what the ATTESA computer in the boot "sees". I tried removing the dampening fluid from the G-Sensor, sure the 4WD system comes on really quick, but that's not what you always want.... And having it engage every time you go over a little bump is no good..... I think the real "delay" comes from the ATTESA computer in the boot - not the G-Sensor... For ppl interested I still haven't given up on my replacement PCB - just so busy with work I never get a chance to work on it. :-( just my 2c Jeff

I was thinking about this just now and it might be also worth checking for cracked / dry solder joints.... maybe when you have the sensor sitting in the car and it's all nice and stable it works. But when you drive around the vibrations might open up a hairline crack and cause the output to drop out for a fraction of a second - enough time for the error to be thrown.... In my experience the cracks can only be (sometimes) seen under a microscope, so it might be worth re soldering the whole board (easy, but might take half an hour or so).... Just a thought anyway... Jeff

Hey - i'm after two things for my R32 GTR. The cap / plug that goes over the drivers side top dash bolt (see attached) and also the cap that fits on the outside of the light switch (again see attached pic) Thanks! Jeff

Hey Mate, (replying to your PM here) So I replaced the caps with three of these (prolly only need two) http://au.element14.com/rubycon/35ml10mefc4x7/capacitor-10uf-35v/dp/8126542?Ntt=812-6542 I replaced the trimmers with these http://au.element14.com/bourns/3303w-3-203e/trimmer-20k-3mm/dp/1689841?Ntt=168-9841 I also replaced one of the 200K ohm resistors (not mentioned in this topic) with a trimmer http://au.element14.com/bourns/3314g-1-204e/trimmer-200k-4mm/dp/1689909?Ntt=168-9909 as I couldn't achieve the correct 2.5v I have some parts here .... Where are you located - maybe I can take a look ? (I'm in Adelaide, but travel to Vic now and again to see my family) Or if you want just send it my way and I can replace the parts, test it, and send it back.... Maybe it's not the G sensor ??? maybe it's actually in the wiring back to the computer ? (or maybe the computer ??) Anyway - good luck, Jeff P.S. make sure you have the car running (idle on level ground) when you set the pots, I found they changed after the car was started... TTYL, Jeff

Spot on... Jeff

Yeah next step is to check the computer in the boot and see what code it is now flashing out. Jeff

Two interesting points here..... 1.) When you say the value was oscillating - what was the range is was cycling between ? 2.) Is the 4WD light off for a longer time than it was before you adjusted the pots ? (May indicate the system needs bleeding...) **Check the computer in the boot now and see what code it is flashing. (Very easy - or if you are not sure have a quick search on this forum) Hopefully it is something other than the G-Sensor now.... Regards, Jeff

Hey, here is a more detailed procedure: 1.) Move your car to a LEVEL sport - **important** 2.) Connect to the black wire from the multimeter to the car body (Car body is ground - negative battery terminal is connected to it) 3.) Set the multimeter to measure "VOLTAGE" with a range of say 0~5 volts (or the next highest setting) 4.) Make sure your G-Sensor is plugged into the car and bolted down as from the factory but with the cover removed 5.) Start the car. Make sure the handbrake is on lol. 6.) Take the red positive wire from the multimeter and hold it *****CAREFULLY****** on one of the yellow pins (note there are three colours on the picture: Red = pots, Orange = capacitors, yellow = test points) 7.) Adjust one of the pots (I'm sorry I forget which pot corresponds with each test point - just use trial and error) so that the test point reads 2.50volts 8.) Repeat step 7.) for the remaining two test points. 9.) IMPORTANT!! After all the pots are adjusted turn the car off and restart it - ***re-measure the test points again to confirm they are all 2.50volts 10.) Turn the car off and restart - you should no longer have a G-Sensor error. Hope this helps. Jeff

Hey, If i ever get my butt into gear and finish this new replacement I would point you towards that. However, in the meantime, take a look at my first post in this forum. The caps don't look like they have leaked ( bit too fuzzy to say for sure). I would try adjusting the pots and see how that goes. The procedure is very simple - all you need is a multimeter and a little screwdriver. Jeff

Some pics from the BLCC Autocross today.... 10th outright out of 60 or so cars. (Hope I attached the pics ok...) Jeff

Yeah I'd be super keen to get together for a fun race / drag or something. I have NO experience racing, (I always drive around by myself.... but am super keen to learn) My charger is still on Kangaroo Island and I'm not going to be able to get to it until after Xmas... Does anybody have dates in mind ? Regards, Jeff

Hey - yeah sorry for the delays..... We bought a house, and have moved twice since my last post. Just moved into our new house last Friday so i'll get back into it in the near future.... My car is in a shed now off the street, so I tinker with it again without having to worry about getting hit by cars etc. Although, all my electronic test equipment and tools are still over on Kangaroo Island at the moment so prolly can't do much till I get it all over here sometime in the next couple of weeks... Jeff

Black R32 GTR on Compass Road Seaford (in the late afternoon)... Only saw it for about 1ms out the kitchen door, but it looked nice.... Jeff

Far out - that sounds serious! The engine is forged build already (o-ringed, forged pistons, rods, etc etc etc etc) I think from memory it runs 14PSI, also runs a custom built clutch, clutch fork and thow-out bearing, along with an adaptor plate into a liberty gearbox as it kept blowing the standard RX turbo box (even with oil coolers & pumps everywhere lol) He mostly uses it for Autocross events now, as being a factory special built car it's a bit of history that shouldn't be crashed lol... Thanks so much for all the info, i'll pass it along and keep in touch... Jeff

Cheers - thanks for the info guys. Yeah I'll take a few pics next time i am over in Victoria. Actually come to think of it we are doing the BLCC Xmas Autcoross - i'll take some action shot then. Thanks again, Jeff

Cheers mate, my brother runs a Microtech on his CA18DET Bluebird, seems to work really well. I'll give them a call. Regards, Jeff

Hi All, I realise this isn't a Skyline question, but I thought i'd see if anybody can give me any feedback. My old man is restoring / racing John Atkinson's original 1984/85 Subaru RX Turbo rally car. The build date is a bit iffy as the car was a factory special build and was never fitted with a compliance plate. He was asking me about fitting an aftermarket fuel only computer. I had a hunt around any couldn't find any direct plug in systems like the good old power fc. Does anyone know of any ? Or can anybody suggest a cheap(ish) easy to wire in fuel only computer ? Thanks in advance, Jeff

If the G-Shock indicator has gone red then it's probably still fine (or might just need the bias voltages adjusted as per my pic at the start of this thread) If the whole unit has cracked and the silicon dampening fluid has leaked out of the hall effect / magnet pendulum cavity then it's prolly NFG. I'd take the top off and adjust the bias voltages first. If it's been hit the worst thing that can happen is that the magnets mounted on the small pendulum spring will be bent a little (ok) or bent a lot (nfg unit) inside it looks like this Just pretend the magnet is a rock mounted on a piece of string. (Really it's a magnet moulded in a lead weight mounted on a spring all sitting in some thick fluid.) "x"'s = Fluid ----------------------------------------------- (PCB) xxxxxxxx|xxxxxxxx xxxxxxxx|xxxxxxxx xxxxxxxx|xxxxxxxx xxxxxxxx|xxxxxxxx xxxxxxxx|xxxxxxxx xxx(Magnet)xxxx |Hall effect sensor| As the car undergoes g-force the magnet moves closer or further away from the sensor. After years of movement or an impact they look like this (Dramatised) (Edit - this should look bent to the right - added x's so the alignment works) ----------------------------------------------- (PCB) xxxxxxxx|xxxxxxxx xxxxxxxxx|xxxxxxx xxxxxxxxxx|xxxxxx xxxxxxxxxxx|xxxxx xxxxxxxxxxxx|xxxx xxxxxxxx(Magnet) |Hall effect sensor| And therefore the output of the op-amps feed from the sensor needs to be re-calibrated, the bend in the spring taken out, or the unit replaced. Hope this helps a bit and that the text pics look ok Jeff

Almost ready to send the PCB away... Just wondering does anybody have an R32 G-Sensor (a really good one) they I could borrow for some testing ? I think mine is ok, but i've done some tweaking so i'm a little unsure how "original" the outputs now are. I'll be at SAU Nationals (Just the Race Day - spectating) I can post it back after i'm finished with it... I don't plan on opening it up or anything so nothing *should* get damaged - I just want to monitor the output against my new replacement when it's up and running. Cheers, Jeff