Chris77

Thanks for the reply , even over the festive season . The person who assembled the intake and did the mechanical bits wondered about an exhaust leak , I can see this with the o2 seemingly coming better with more air flow (revs/load) but have not worked out why its fine for the first few minutes after start . maybe its just the cold start after all . I will get the file and logs off the other laptop an post up in the next few days . The lambda sure is a mess in the log . The engine seems to run smooth and does not seem to fluctuate along with the o2 signal . Cheers Chris

Ok , well thought about this for a bit and realized its easy enough to answer one of my questions . Hooked my o2 sensor system up to my power supply and it cycles from 1.5 amps to 0.05 amps every few seconds and it did this for 10 minutes , I got bored at this point . So its safe to say the sensor heats continuously , so heat is not my issue . AEM manual says 18 inch from the head and we would be about that from what I've seen . It may not be the 10 deg up per the manual , I did not install it so I'd have to check that . Not that this makes it correct but my sensor a few deg down and it has survived , I know tow wrongs dont make a right . Left field idea , could it have a blown head gasket and be spitting water down the pipe and its buggering the reading . When under light load there is enough airflow over come this therefore it reads . It reads ok for the first few minutes from start as the pipe is dry . Yeh as crazy as my first idea . Cheers Chris

Hello This is what happens when amateurs mess with things Short version , afr guage goes lean a few minutes after start , second afr system does the same but comes back at mild rpm/mild load . I've wired an atom g4x into a off road vehicle running a rover v8 . The carb intake has been replaced with a later model injection intake with factory injectors , custom trigger wheel in the dizzy and wasted spark coils . AEM o2 guage via analogue input . Much to my surprise the stupid thing fired up as I was trying to test the trigger pickup , go figure . Injector dead times are unknown , if anyone knows what 94 rangerover injector figures are or where to find them I appreciate a head up . Anyway thats about as far as I got as a couple of minutes after start the afr started going lean . My first thought was the cold start was ramping off too fast so I started to chase it with master fuel (this was the first start etc ). It quickly became clear this was a false reading as the engine bogged and belched smoke . Tuning it to max vacuum at idle put me back to the original master fuel . The afr guage dashed out , however the engine seems to be idling just fine , smooth with no misses etc . Wondered if I have just cooked the sensor . Day two and I swapped on my o2 sensor system from a working setup and it did the same thing , interesting . However lightly driving the thing and the sensor comes back after about 10 to 15 seconds or so , after returning to idle it eventually rolls lean again . During this time the fueling does not appear to change significantly , the motor sounds and runs smooth . So at this stage I think its guage wiring or placement issue . Hence the suspected heat/location issue . As above , amateur , so bugger all experience with failed o2 setups . First guess is its lack or heat , key on heats the probe so life is good , however the probe is too far down the exhaust so cools off and shows lean . Drive it a little and the sensor sees more hot gas and warms up thus reads again. The sensor is in the end of the 4-2-1 collector , about the base of the firewall , so further than I would like but not miles away ( I thought ) . Second guess , well dont really have one . Maybe an air leak up stream , but why is it good for the first couple of minutes and why does it come right being driven . I have had a quick google and one post has the same fault but does not give any solution , another from this forum says after replacing the faulty o2 sensor he found the master fuel was way to high . I do not believe the sensor is faulty as two systems show similar results , different o2 sensors and wideband controllers . So what are the common o2 sensor issues ? I'll google some more but do the controllers heat the sensor constantly or only at power up , this will debunk my heat theory straight off . How far is too far down the pipe ? If the sensor is not in the pipe enough can this cause issues , I would have though it would have to be way wrong to give this sort of an issue . The sensor is located at horizontally so not collecting moisture etc . Sorry for the novel but interested in any responses , cant progress with this until this issue is resolved . Need some confidence in the afr reading . Oh and if it matters (as it was mentioned in the thread with similar issue) master fuel is currently 17 and the fuel table is about 48 (too high to me) . Change of master fuel from 16 to 17 moves the afr (when it seems to be reading ok) from 13.5 to high 14's . Bigger jump than I expected , but if it was working I'd run the higher master fuel and bring the table down . Cheers Chris

Thanks for the prompt reply , was not expecting anything until the next day or so . We have had a double 12-1 tooth machined , so from this point on what can possibly go wrong . So from this I can assume the ecu looks at the teeth for speed and tdc and calculates all the trigger points . Either way stuff I dont need to know/worry about . Thanks agian Chris

Intending to be Atom ecu , rover v8 with wasted spark . Trigger wheel in the dissy , so a "cam" sensor with a missing tooth. I am way behind the curve with the link ecus and I am trying to figure out how many teeth to put on the wheel , it will be a custom wheel . Other more questionable ecu's I have fiddled with require a tooth to trigger an ign event , ie I would need a multiple of 8 teeth on the wheel . I am starting to get the impression the link does not do this and just calculates timing based of a full rotation of the wheel , 720 engine rotation , and the trigger point . In my case the missing tooth .This is based of the warning in the manual about not using a 32 tooth wheel as it does not divide into 360 . Is this the case ? Can someone point me in the right direction to find some more info on this . The wheel will be about 75mm in dia so an edge length of about 235mm , so a 24 tooth wheel would give about a 10mm pitch , ~5mm tooth width . 36 is starting to get a little small around 3mm I would expect . If the number of teeth does not need to have any relationship to the no of cylinders , would I be better turning this into a "crank" sensor and have two patterns of 12-1 . Would this aid startup by establishing the signal quicker . Maybe just going to less than 24 teeth . I have seen the recommendation for the vr teeth to be about as wide as the sensor . This will be a hall sensor but I expect about the same to be true for these . To clarify , the engine is not a race engine so any losses due to the slack in the cam/dissy drive are what they are . This engine will be in deep mud so keeping the wheel and sensor up and protected is a priority , as is good starting . Thanks Chris

Been meaning to post all week . Thanks for the info , most appreciated . This sort of support you give for obsolete models is great and why I would recommend link to others . This setup will hopefully get the engine going and the project up and running but I know down the track in the not too distant future it will need to be upgraded . Thanks chris

Hello I have acquired some parts from a Mazda RX7 and one of them is an old link ecu , its tagged RX7 S4 D42V5d 270505 . What is the closest manual for this ? Mostly wiring I guess . Also is there anyone in the Auckland/nth Waikato area with a Serial link interface that could read the ecu and see what the tune is etc . I dont want to tune the ecu so dont really want to go out and buy one . Thanks Chris

Hello I am looking for a number or link to , hopefully , a bulkhead connector the matches the ecu plug . Long version , I wired in an atom 2 into a friends offroad vehicle a while ago and all was well right up until he cut it up and made a tube chassis and moved things around . Now he wants to relocate the ecu , grrr . While its probably not the best to have a join in the wires , the best way I can think to do this is to get a bulkhead connector and connect it to a new ecu loom , this will give a me a small extension so to speak and actually be rather convenient place for a bulkhead connector . Does anyone know if the ecu plug has a match like this . From my initial google it seems it may be part of the amp superseal series , but I dont what to order one to find out its not correct in some way or the keying is off . Thanks Chris

Well I had a look at the car last night , the fuel pump relay was faulty . Odd as that is what the owner said was replaced and as I said not done how I would have liked . You dont leave an aftermarket relay with bare terminals pushed on the ends floating around in a factory relay box . Anyway still no go (well maybe) so after verifying the pump worked when the pin in the ecu connector was earthed I pulled the ecu out . Looking at the header joints as suggested above , it appeared the fuel pump connection was cracked , I would have missed it had I not been specifically looking . I could have been looking for a fault that was not there but given the pump issues and only the pump connection looked bad I decided to resolder the connection . The rest of it looked good , I found a date on a sticker inside , something 2004 , so reasonably old . Put the thing back in the car and it still did not go , then I remembered the kill switch and it was away . So now I am doubting my self and did I turn it on after fixing the pump relay . Reasonably sure I did but ... So thanks for the info , its great to be able to get a little help with these old units . It means the guy can carry on racing the little car for a few more years before an upgrade . So now to go and find a wiring/pin out for a G3 , a mate pulled a 1600 turbo out of a car with the ecu to put in his 4x4 . If I am ever going to get it out of my shed I had better get it running . Thanks Chris

Hello I am yet to check the car myself and I learnt a while ago to always take what is said with a grain of salt etc . However the guy says the car runs fine when they hot wire the fuel pump . I have checked and they are hot wiring the pump back at the pump , not as I would have say across the relay . This just means I have to back track all that wiring and check it out . He advises someone has already done that and replaced the relay , hmm , theirs that grain of salt again as I do not think a professional auto sparky would wire in the relay the way it is . They have smashed out the back of the factory fuse/relay box and poked an aftermarket relay in there , bare terminals just individually pushed on to the relay pins . I am not a professional auto sparky either for the record . When looking at the relay I noted 3 factory wires and 2 addon's , yes 5 wires on the relay odd . After reading the lemv4 manual it says the fuel pump wire is purple and one of the add on wires is purple , so atleast I am on the right track . The car only got dropped in my lap last night and I am going away for a few days this afternoon so once I am back I will check out the wiring side first and if it checks out look into the ecu and what can be done . Thanks Chris

Hello Usual story , a mate dropped a car off saying the fuel pump does not work anymore . Says its been iffy for a while now but now dead . Had the wiring checked and been told its the ecu . I am not familiar with link ecus . The sticker on the outside of his says "Link Reluctor , D42V2 , 220704" . If I was to guess , from another post I read here , this is a g1 link and next guess is its ignition trigger is a reluctor . I will go and check all the wiring for myself first but I was just trying to get an idea on what the ecu can do . Wondered if the fuel pump output was iffy could it be swapped to another output . This does not look possible , again a guess as another post said to read the lemv4 manual . Is a fuel pump output a common failure ? If it is crock is it worth getting the ecu looked at , if so where ? Thanks Chris

Hmm , well now don't I feel stupid . Many thanks . I will try it on the car this evening but it work on pc link on the work computer here pressing enter . Cheers Chris

Trigger setup is set to Multitooth , priority trig one and rpm 1-default . Trigger one set to optical/hall , was set to crank , and 8 tooth count . Changing this to Cam in PC link not connected to the ecu still does not enable trigger offset for me . I am not sure how/if I need to disable trigger two , the single "cam" trigger and in effect its not used at this stage . I was hoping having it there would not be an issue , I expect its not when its set up correctly . I will go and read some more and see if I can work out what I have done . Thanks Chris

Hello Second question . Atom ecu running chev v8 with a holley dual sensor distributor . The distributor has two hall effect sensors in it , one an 8 tooth crank and a single tooth cam (as you guys sorted me out in my first question ) . I have wired up the two sensors as in the future my mate may want to go with wasted spark . 8 tooth to trigger one and trig 1 is set as priority . As it is using the distributor I set the ignition mode to distributor . When I go to set the trigger offset , it and the reference timing seem to be locked out . Is this because I have selected distributor mode and in theory I need to set the distributor trigger to the reference timing ? If not why is this locked out ? The popup window comes up and I can enter a value for reference timing and trigger offset but they do not stay in the settings when I close the window . The issue is the holley distributor is expected to be set to trigger at 50 BTDC , and the sensor is locked to the rotor cap . So I can't just rotate the distributor to get TDC or close to it as the rotor will then be out of sync with the cap . Thanks Chris

Ken , I dont understand the pairing you mention . Drawing it out the link pairs each 2 but one , so many 180 deg out . The pattern you give with the firing order you say puts two the same as the link but the other two , one is next (90deg ?) and the other is 3rd after . However your pairing with the link firing order pairs each injector . Will have to sit down and work out the alt firing order , I deal with 4 cyl , I need to hands to work with 8 cyl . Thanks for the replys Cheers Chris inj pairs.pdf

Ok , so I am looking at this backwards . Trig one wants to be the 8 tooth and trig 2 is the single tooth and select cam 1x . So thats easy I can wire both and only set up the 8 tooth . Great . And reading the manual again it implies using all injector drivers unless too have too many injectors . Thanks Chris

Atom ecu , chevy v8 with Holley dual sensor distributor and 8 fuel injectors . Installing the atom in a friends vehicle and he still wants to run the distributor for ignition , at some stage me may go to a wasted spark setup . To run in distributor mode I understand the secondary sensor of the dist will have to go to trig one , ie the 8 tooth signal . My two issues is I would like to wire up the two sensor inputs , one is a single tooth tdc and the other the 8 tooth spark . If I use both sensors I believe the tdc trigger has to go in trig one ? Is there any way to set the ecu up to receive the tdc input and then fire the same ignition signal out ? Two reasons for this , one if he upgrades to wasted spark the wiring is already there and , two , could I then utilize the semi sequential fuel control . Tied with this for fuel control in mutli fire can it still use the 4 outputs , ie can I wire up the injectors now as per the semi sequential diagram and run multi injection with the 4 injection putputs , or under mutli will it only run 2 injection outputs . Sorry as you can tell I am not familiar with the link ecus and would like to get it future proofed for him if I can , so any input would be helpful Thanks Chris