Jump to content

new G4 link plugin ecu owner - first question

anthony mcgrath

Recommended Posts

hi all I'm anthony, I'm based in merseyside and I've been working on a top mount turbo conversion for my car - a nissan skyline R33gtst RB25det. The full spec is quite mental - the original owner rebuilt the bottom end about 3 years ago and I've decided this year to do the top end, swap turbo, manifold, plenum and throttle body. The turbo is a Garrett GT3076R turbo and I'm aiming for 500bhp at the end of all this. I work as a computer animator for Sony most of the time and mess about with all manner of 3d nonsense which I've plonked on youtube under the same username heh! If you fancy a longwinded read with lots of pics the origina thread is here :)http://www.skylineowners.com/forum/showthread.php?t=142942'>http://www.skylineowners.com/forum/showthread.php?t=142942 I've recently got everything buttoned up and plugged my G4 into the car. I've updated the software on my laptop and the firmware on the ecu and I've moved onto step 6.3 in the manual which is MAP SENSOR CALIBRATION.. (your all gonna chuckle when you read this!)... my first Q is in the manual it says 'under the analog channels menu select the AN volt channel that has been wired to the MAP sensor. Select the correct sensor type'.... a> however I cannot seem to find the 'analog channels' section... a> the only thing I've found is this menu at the side... a> any ideas on how to get to this analog channels section? It seems alot of the other steps for TPS, IAT etc are all accessed from the same area ta ant

Link to comment
Share on other sites

Hi A. Welcome to the forum. Seems like your having fun with your project.

Now. Im not sure i follow what your problem is. Or what it is you cant figure out. You ringed the analog input section in picture 3. Thats where you configure what inputpin your mapsensor is hooked up to. Here you also select what sensor it is. If your sensor is not listed you need to configure one of the calibration tables (at the bottom of this section) to fit the sensor you got.

Then you click at the 'options tab at the very left top of your screen . Between the 'File' tab and the 'ECU Controls' tab.  There at option 9 from the top you got 'MAP sensor calibration' (Right below 'TPS setup' which i can tell you also need to do)

Link to comment
Share on other sites

Hi Anthony.

Steve is on the right path there.  The basic construct to give you an overall idea are the wires going out to the car from the 'plug in' are all either wired from one of the following 3.  Of course there are a couple of other things like grounds and +ve supplies and so on too, but for the purpose of the description this is adequate.

'Digital Input', otherwise known as a DI (takes input from things that go on/off, maybe a switch, a digital signal etc)

'Auxillary', known as an AUX (output that drives things like fuel pump, cam solenoids, AC clutches etc)

'ANVolt' (takes a variable signal in from things such as TPS, MAP, Wideband O2 etc)

The next bit to understand, is in line with each available input/output (I/O), there will be an associated channel within PCLink to set up for the particular function.  For example:

Your TPS will output a variable voltage from 0-5v, so this has to be wired to an ANVolt (plug in will already have this wired for you though).  Once you select the appropriate function for that channel ie. TPS (main), it now knows this voltage is from the TPS.

PCLink is very powerful, and cannot be explained entirely here as you would imagine, I just wanted to give you the principal, and let you know when these windows pop up when selecting functions, you can use the padlock to lock them there, so they are not replaced with the next choice.  In fact make your own tabs, name them what you want, put what ever gauges you want on them, MAKE IT YOUR OWN!  :)  It's quite cool really.

I realise you may already know some of this stuff, but if I get this out on a post, others that do njot entirely understand may be able to take advantage of this description.

View the following video for a brief example on this -


Link to comment
Share on other sites

@Steve - yeah it appeared to be a discrepancy in the manual and the software mainly cos the software is updated so much.  I emailed Phil Williams and he said he'll amend manual but I was on the right track as I suspected lol!  The MAP & TPS were very easy to setup so thankyou :)  I also recently figured out as you point out about the cal tables which I figured would be handy if you cant see a listing for certain things.  For example I've wired in an AEM UEGO wideband sensor today - got it workng with the gauge but I'd love to get the ecu to 'see' it so I'm guessing I'll need to use a cal table to define the AFR vs voltage or something?


@ Jurgen - the ability to configure the user interface how you like is whats throwing me hehehehe - a couple of ppl keep sending me screenshots and they have it setup so differently from default layout lol!  thanks for the explanation to so in short:

DI - in/out signals - switching on powersteering etc?

AUX - parts of the car the ecu controls as you say like priming fuel pump etc..

AN - analogue inputs such as throttle body sensor or maybe wideband?

theres a heap of stuff that throws me - I'm still very new to all this but this part of the car is the bit I've been itching to pick up and learn so please bear with me if I'm getting my terminology screwed up at times.


@Martin - thanks mate I didn't want to pester you on there as I didn't get the ecu from you and it feels a little cheeky asking you for all the advice :/  Any advice you can offer tho will be greatly appreciated - as you said  on SOCOM ppl need to get out of their heads that mapping cars isn't a voodoo magic and need to start getting into it.  The very fact I'm willing to plug an ecu into my car seems to freak eveeryone at work out with their financemobiles :/


Well theres a tonne of questions for me now - things like whether I need the NB o2 sensor at the moment especially if I have the wideband one plugged in there (didn't seem to affect the car starting up tho).  I'm not sure how to get the AEM UEGO to be 'seen' by the ecu.  I figure that you use a cal table to define afr and voltage but can I get the ecu to look at a pin on the ecu plug at all?  That way I could fit a pin to the white wire off the AEM wiring, plug it into the ecu plug, then configure the ecu to look at that pin for the signal!


again thanks for all your help guys!


Link to comment
Share on other sites

Ah.. Now i understand where your coming from on the matter.


Yes you can/should hook up your wideband to your ecu. You just pick one of the Analog inputs you have not used yet, and select 'wideband' from the dropdown menu. Now, as your WB is not listed in the software you will need to use one of the calibration tables. I dont know the WB you got so i cant tell if it gives a linear output. But i guess it does. As you probably have noticed Calibration table 1-3 difffers from cal 4-6. 4-6 are the ones to use with a linear signal. ie. 0V=10AFR, 2.5V=15AFR, 5V=20AFR. That would be a linear output. Now if it was 0V=10AFR, 2.5V=13AFR, 3V=16AFR, 5V=20AFR this would be unlinear output so you would need to use tables 1-3. Personally i have Cal 4 table configured as follows:

output values = AFR

Output value a = 10 AFR

output value b = 20 AFR

Input value a = 0.00 V

Input value b = 5.0 V

Again, this is MY settings with MY particular WB 

Once hooked up you need to verify that your gauge reads the same value as the ECU does. If not you need to sceew the cal numbers a bit until it matches My widebands reads 14,7 if i unplug the sensor from the controlbox, so its easy from me to check this. Dont know if its the same for the AEM. Read the manual i guess ;)

No you do not need the narrowband lambda if you hook up your WB.

Link to comment
Share on other sites

hi Steve

many thanks mate - I'm just fiddling with the Nissan plugin G4 R34 .pcl file included when you download pc link.  I notice AN VOLT1 is empty so I set that to wideband.  I was however pointing it at  Cal Table 1 as follows..


on the right of this table a graph appears and its linear in fashion - much like a wideband sensor voltage vs afr diagram.

at first that looked right to me but now I look at it again it doesn't heh!



Link to comment
Share on other sites

Just be aware that there are some differences between the wiring on the gtr vs gts. Things must be configured correctly for your car here (obviously). You could always use the input that was used for the NB lambda  you are not using anymore. But it doesnt matter.

That looks linear to me, so you could have used the other table type. Just remember that you only got 3 of each calibration table. So use them wisely. 

Link to comment
Share on other sites

hi anthony great to here you have fited a link ecu, just a small bit of advise and i dont mean to be rude but you should really take your car to a link tuner to tune once you have it tuned then study it and imrove if you can there tune as it is very expensive when or if you make a mistake. which as you know will set back the pleasure of enjoying you ride. the base map allows you to start your engine only and five hundred hp is very high hp i build and tune rb engines as my main type of engine  and can advise you on what you would need to fit in order to acheive this but you need to  do internal things to make it last

cheers Ross



Link to comment
Share on other sites

@Steve - Aha so I can use the NB by simply switching it to WB and configuring a cal channel - that sounds cool - thought I would have had to keep the NB left as is.  I was roughly aware of gtr vs gtst differences (thinks like high imp. vs low imp. injectors) but I like the way the link uses the same pin for IAT as the gtr does (pin36) - smark thinking on the parts of the boys making it all this work easily :)

@Ross - not to worry I wont be just putting this in the car and flying up the road heh!  I've no experience of tuning a car as such - its just reading that I've been doing and I'm not brave/dumb enough to just go put that into practise without some company/coaching!

I did an EFI101 course about a year or so back and wanted to do the advanced course, but cant afford the pennies yet.  There's a coupla guys down south who have very kindly offered to let me tune my car with coaching and tuition both on dyno and on rolling road so I wont be doing anything brave till I know what I'm doing which seems a long way off.

I was aware of the base map being used to basically start the car - I was hoping it would be okay to just drive around the crescent a good few times where I live basically ALWAYS off boost and with autotune allowing the car to possibly map some of the low load cells itself using the WB input.  I'm a patient guy and have a light gaspedal foot so wont be blowing owt up anytime soon I think doing that surely?

As for internals - its all forged, compression lowered for the extra boost.  Wiseco pistons, Nurspec conrods, ACL bearings, ARP studs, cosworth headgasket and numerous other goodies like injectors, FPR etc.  Cyl head is rebuilt.  Fitting an oil cooler at the moment and sandwich plate for oil pressure/temp gauges to keep an eye on things also.  I do need an EGT gauge ideally in there too!  I need to uprate fuel pump but that'll have to wait for the moment (money!)

I'm shooting for 500 but tbh if I only get 400 with whats on the car now I'll be happy - I've had a mare with the car thanks to a cowboy 'mechanic' who busted a cambelt job which is what caused the top end rebuild so I'm just trying to ensure I do things right here for myself :)

Link to comment
Share on other sites

Aha so I can use the NB by simply switching it to WB and configuring a cal channel - that sounds cool - thought I would have had to keep the NB left as is.  I was roughly aware of gtr vs gtst differences (thinks like high imp. vs low imp. injectors) but I like the way the link uses the same pin for IAT as the gtr does (pin36) - smark thinking on the parts of the boys making it all this work easily :)


you need to change modes for CCL to Wideband.. then set the gain and lockouts and the AFR table.


I was aware of the base map being used to basically start the car - I was hoping it would be okay to just drive around the crescent a good few times where I live basically ALWAYS off boost and with autotune allowing the car to possibly map some of the low load cells itself using the WB input.  I'm a patient guy and have a light gaspedal foot so wont be blowing owt up anytime soon I think doing that surely?

the basemap is suitableish for starting the car.

its faster and easier to do a quick tune yourself for fuelling..

the basemap ign is not great.

make sure you align timing and ign drift. (ignition delay).

as for EGT gauge.. buy a type K thermocouple and an EGT amp. then send the 0-5v to the ecu.. a logging and trimable parameter is much better than a gauge..

Link to comment
Share on other sites

hi Martin not sure what you mean by CCL but basically I switched AN VOLT4 to wideband then configured CAL4 with the following:

output units - AFR

output A = 9.5 AFR

output B = 19.5 AFR

input value A = 0 V

input value B = 4.97 V

success - the ecu seen the wb signal altho it appears a touch out from what the gauge is showing.  Not quite sure why.  Its certainly not miles off but it does seem as tho the ecu responds quicker than the gauge!

anyway managed to get it idling better fixing the cars ign timing using the Crank Angle Sensor - set the GTST for 15 degrees.

however in the ign table the ecu appears to be pretty much 20 degrees across the low load cells - I observed the ones that the car was idling in and adjusted those to 15degrees - car stopped the little missing it was doing pretty much straight away.  I haven't adjusted anything else but even the AFR seemed to drop from the 16's to about 15 too

beyond those little bits of tinkering I'm lost with regard to the fueling etc and dont fancy playing any more without tuition and having the car on a rolling road heh!

Link to comment
Share on other sites

  • 2 weeks later...

small update to all this:

I got my wb calibrated with the ecu so thats cool.  I've also aligned the timing and ign drift as Martin suggested - I was taking the timing signal off the white loop at the back of the block off the wiring loom and the signal is terrible.  I used a piece of amp wire connecting the coilpack to the plug off cylinder1 and the timing signal was alot better.

in the ign timing calibrate options, I only really had to change the first value to 15 instead of 10 and adjust the second parameter on idle a touch.  My wife took it up to 4000rpm on idle and the ign delay seemed fairly okay so I left it as is for the time being.



Link to comment
Share on other sites


Just be aware that all the timing figures on 'IGN tables' are based/referenced off this, and it is not wise to be driving it anywhere without doing the first most important step of the whole process.  Calibrating your timing.

If you have calibrated your timing to a base of 15deg as pictured, and previously you were on Zero.deg... And the numbers in the IGN table have not been changed, you would have been running another 15deg advanced from what the table thought.  Can you say 'Knock'  :)

Just be careful mate, if you are not used to doing these things, it might pay to follow the instructions word for word and ringing a pro dealer that can help you out with good advice.  What ever you do, without a tune in there... Do not load up the motor with more than a free rev or drive on to the dyno.

Good to see you are getting somewhere though, it's nice to follow the stories.


Link to comment
Share on other sites

thanks Jurgen

I'm pretty confident the ign calibration is all sorted but I might get it in me garage and give it a triple check to be sure.  I'm not sure how clued you are on the 33gtst (more than me I'll imagine heh) but for the purposes of anyone else reading up on here...


Just to explain where I went wrong firstly... I set my timing gun to zero degrees & did my first calibration.  I was getting readings of 25+ degrees and it was bouncing about somewhat.  I would rev it up to 3000rpm and hold it there but the ign signal was terrible.. unreadable...

Martin Battye phoned me and explained the best way to deal with it is set the CAS on the skyline to the middle.  Use a dumb timing gun (or set mine to zero which I'd kinda figured beforehand) BUT read the signal off number one cylinder using a coil lead between the plug & the coilpack.  previously I was reading it off the ign loop at the back of the engine block.

The signal off cylinder one using the coil lead was MUCH clearer.. on idle I was able to see that the ign timing was a little out, so I adjusted the 2nd figure in the calibration options...


I then took the rpm up to 3000rpm and checked the ign timing again but it seemed to be holding steady, so the third option (ign delay in ms) I didn't need to touch.


Martin Battye (one of the forum users) helped me out and sent me a fuel & ign table and gave me some help over the phone.  The car has been ALOT smoother to drive since!  As in an entirely different car.  It is a touch rich but with any luck I'll be able to adjust that using the runtime values from the wideband which Martin also helped me set up.

I haven't been loading it up - literally cruising to work & back off boost at all times - I have a good accurate boost gauge, and been keeping an eye on that and haven't even taken it onto boost or beyond 3000rpm in just about any gear.  I've got a light foot :)

Martin is a bit busy at moment but going to be heading up here to help me get it tuned & driveable and I reckon he'll double check all the ign calibration for me too just to be sure.

I'm not too bothered about making the power just yet - if it makes actuator pressure I'll be happy then I up the power on a rolling road at a later point.  I am being careful with it tho :)



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...