Hi all Have a strange problem .... Motor taken out and fitted with new Turbo's / manifolds etc Installed brand NEW 63564 SARD 800cc injectors (and already have Nistune fitted) I have good Spark / MAF/ Injectors are firing electrically and No Air Leaks - problem appears to be a lack of fuel .... (will stumble with some aerostart otherwise will just crank over if none is applied ) The Fuel rail and all lines have already been pressure tested and it holds pressure The Regulator also holds pressure - on crank at 43.4 PSI with vacuum off No Codes are being thrown and all values including TPS are correct at .46V The Duty Cycle is registering at 1% while cranking - indicating the injectors are firing mechanically as well as electrically but just at a low duty cycle (also have noid lights that confirm injector and spark signal is good - have visually / physically checked them as well ) Upgrading Injectors from 370cc to 800cc means I had to load the stock map then upload the 800cc injector size to calculate the K value ..... have tried adjusting lag values - but still have no luck in starting .... Have tried both stock 370cc and 800cc settings .... but the engine doesn't even stumble .... It is as if - there is just not enough fuel coming from the injectors ? (hence why it stumbles and almost starts on aerostart) I can only think that this could possibly be related to the Nistune Settings being not correct (Lag / Duty Cycle etc...) Any ideas on what could be causing this lack of fuel from the injectors ? Cheers and Regards Jamie
First off, are you using the nistune feature pack or the non feature pack? Are you using a wideband? You cant just input values and hope for the best, use a wideband 02 sensor.
Non Feature Pack ..... I do have Wide band fitted but it is not wired up yet .... Oh Shit - I was actually under the impression that Nistune would calculate the 370cc to 800cc and adjust the K value / MAF values automatically (based off the generic Maps available and the injector resizing feature) to the point where I should at least get a start ... (even if rough) ... then I could use the Wideband to hone/ tune in the Maps to the stoichmetric values .... Looks like my next step .... is wiring up the Wideband Sensor Thanks for the feedback - appreciated greatly ! Regards
You should be able to do that with the "resize injecters" function because that's exactly what I did when I put 640cc injecters in. It'll be rough enough to start it and take it to the tuner. There should be a walk through on the nistune website to make sure you've done it right. Have you checked all the simple stuff like connectors sitting properly, correct wire to correct injector, pull plugs and they're wet etc.?
The Nistune resize function roughly adjusts the K value for the size of your new injectors (mathematically), but assumes you are using oem/Nismo style injectors. If I remember correctly, they use a .75 latency. The Sards are probably double that (depends on model) If I was you I would get your WB connected (crazy not to) ...... then jump onto the Sard website and find the latency for your particular injector. THEN, jump onto the Nistune site and read, read, read ........ it can be very confusing until you 'get your head around it'. You cannot have too much knowledge when it comes to tuning
Hi J3bba - to clarify; No Codes / No Air leaks present / New IACV fitted (possibly under or over idle...assess further once idle / stumbling ) Engine turns easily - as if assisted ....but not firing... There is NO stumble present at all The Injector Noid light activates on the injector signal (CAS/ PTU and Injectors must be wired / fitting correctly - TPS signal is good at .46V) Injectors can be heard firing mechanically (Mechanical Tap Sound present but soft) Get an Injector Duty Cycle of 1% when cranking through Nistune The Spark Noid test light activates on the coil signal (Coil pack must be wired / fitting correctly) The spark can be visually seen jumping to the block when out! The Fuel pressure system has been fully tested and passes all tests The spark plug is dry when removing..... So we ran Aero start into the balance tube and it wanted to start. This confirms the spark is working correctly but there is not enough fuel ..... I enter the stock bin map file for JDM 92 AT - it asks me for MAF - I go to open a file and there is only one selection 500 HP VG30DETT ..... any other HP selection is for other cars ... so I have to select 500HP MAF settings Then asks for Injector Size - tell it 370cc to 800cc - load the image to the ECU So I go to Start... and then the above occurs .... Hi Zx299 Sard lists the 63564 latency as 1.6 latency (ms) ...so that double figure sounds about right.... It also explains Nistune wanting to put in 750 ms generically ... (it also actually explains what Matt @ Nistune was referring to in a Sard post with "double the number" so that is very helpful in understanding why I was actually doubling the number ...lol) I will wire up the Wide Bands ..... and I will keep reading Nistune Manuals in the meantime .... Then have another crack at it .... Thanks
You need to first understand how this all works by reading the manual while playing with the maps in Nistune (just on your computer, not plugged into the car - suggest will take several hours). Following are my notes from when I installed my Sard 650's. I ended up leaving it at 1500, even though Matt & Nistune was adamant that was way too high, but they've been running perfect at that figure ever since. Resize Injectors Current: 370 New: 650 Selected: Adjust Load Max Limit. Select: Adjust Cranking Tables. Selected: Adjust TIM/TID Select: Burn changes permanently Injector Latency: Increase from 750 to 900 Select: Burn changes permanently Power cycle ECU Save as 2017-08-22 Nistune650Modified Cranks but no sign of starting. Increase Crank Enrich table values. Increase Injector Latency to 1500. Save as 2017-08-22 Nistune650Modified2 Cranks and minor signs of firing but doesn't start. Battery now getting low. Reload Nistune370Modified Resize Injectors but don't select Adjust Cranking Tables. Injector Latency: 1500. Save as 2017-08-22 Nistune650Modified3 Recharge Battery. Car now cranks and starts OK. Test reducing injector latency as low as 900 - car stalls. Idles very lean around 1200. Runs best and in closed loop around 1500. Still having problems starting the car now warmed up. Increased Crank Enrich table values for all steps currently below 10 to 10. Now starting and idling OK. Save as 2017-08-22 Nistune650Modified (overwrite previous version). Delete Nistune650Modified2 & 3.
Agree you should have a wideband sensor especially if doing this stuff yourself, but it's not going to tell you anything if the engine won't start. Also I wouldn't be doing anything more than idle and light load to 2000rpm (ie closed loop) before taking it on a trailer to be properly tuned on a dyno. The wideband will help you get closed loop operating smoothly.
Here i am with my graphs and lectures again... First. We all (or at least the people being in this game for some time) live by the fact that as a Z32 owner there are some essentials or must haves. That being a FSM (Factory Service Manual for you newbies ) and a Conzult (or simlar) software for codereading and watching live data. I on the other hand have a 3. (and really a 4.) tool that i find i cant be without since i first got one. Not sure wich i want to put on 3. or 4. but they are a good GRAPHING multimeter and an oscilloscope. I actually found one of the GMM i have on Ebay (where i got mine) and posted it on a Z32 FB page yesterday for someone to pick up, but i guess it wasnt relevant enough for the admins so it got taken down. Ignorant bastards. Here it is https://www.ebay.com/itm/Snap-on-Va...5:g:yboAAOSw9ClcaFXM:rk:1:pf:1&frcectupt=true Those were about 1500USD back when they came out in the early 90`s. Since i started using those i no longer understand why they even bothered making DMM`s or why i have 3 of them myself. Its very fast and it does possess some oscilloscope qualities. In scope mode it can go down to 5ms pr screen. Which isnt bad for a GMM. I work as a tech/diagnotics guy so i use it almost every day. However an oscilloscope i think is the one you want should you be hellbent on having one or the other. (Got 3 of those as well btw. Scopes that is...) Looking around the FB pages there are constantly posts about people having troubles and usually they have already thrown a bunch of parts at them to no avail. In my opinion most of these cases could have been solved pretty easy with a scope and someone understanding how to use them. Now To the injectors and deadtime. Below is a screenshot of a scopecapture i did on my own car once. What it shows is. The blue trace is me backprobing the controlwire on one of the injectors showing... well voltage at that wire. The red trace is my ampclamp around one of the injector wires showing current draw through that wire. You can see i put up two markers The first is where the injector driver in the ecu turns on pulling the "signal side" of the injector to ground, thus energising the coil in it. You can also see the current draw ramps up from there. The second marker you may notice is at a weird "hump" in the amp trace. That "hump" is actually where the injector pintle starts to move. On the to you can se the delta between those markers saying 1.336ms. Thats approximately how long it was energized before the pintle moved. Not necessarily when the injector started to spray though! That is pretty cool,no? Now in this next picture i have moved my markers. Between those markers there is about 0.8ms (1ms is 1/1000 of a second guys) Notice that little hump in the BLUE line where my second marker is? The first marker is set at the point the ecu cut the power to the injector. The hump actually shows about when the injector actually physically closes (Again. Not necessarily at the exact point when the fuel gets cut of. Important to remember that). Alright. Deadtime.. In theory its the time it takes from when you energize the injector until it opens (sprays), MINUS the time it takes from you cut the power until it closes/stops spraying.... Savvy? If you do that with my numbers you end up with 0,536ms. That isnt necessarily the exact deadtime as remember, its about when it starts and stops spraying which we cant really see. However. Looking at my 14volt at 300kpa section in my deadtimetable in my own ecu i have 0.55ms for my Nismo 740cc injectors. Thats pretty close. But of course it vary on exactly where you put your markers. Its an approximation. If those humps was not there that would show that the injector didnt move. How is that for a diagnostic value? All that said. If you had a scope hooked up to your injectors you would probably see that first "amphump" way at the end of its pulsewith (if at all) showing that it barely opened (if at all) before it got cut down again. It would be obvious where your problem was. The usage of an oscilloscope is only limited by the imagination of its user. That is a fact Get one.
Correct. I'd adjust the K constant in small increments till the car starts. Even better is to upgrade to the feature pack and just adjust the total injection multiplier. I get base maps done in minutes with feature pack ecu's.
