Lean issue Headache. Have tried EVERYTHING

Discussions concerning the M7790 cpu

Moderator: Matt

ihatemy240

Lean issue Headache. Have tried EVERYTHING

Postby ihatemy240 » Wed Dec 28, 2016 4:24 am

Alright first post, ive been asking around other forums, locals and facebook groups about my issue. Hopefully someone can shed light into this.

Issue is since my rebuild of my ka24de car has been running extremely lean. Reads off my wideband in the --- range which is 18+ afrs. I should mention I have a ROM tune from martin. Had tune from him before and worked flawless on my stock motor running 720cc e85 and z32 blow through.

I decided after rebuilding the motor get some 1000cc injectors and get a retune for it as well as a switch for pump and e85. Before I sent out the ecu my 720cc on the old tune I did the first start up and it was miss firing due to a sticky injector which im assuming was from sitting and had no cleaning from old e85. I throw the 1000cc with new tune on e85 with fresh gas in the tank. Go to start and is extremely lean, hardly idles and dies.

Things ive checked are
no ecu codes
MAF, swapped another working maf, correct voltage and wired correctly. Did have an issue wiring into my new WS since they decided to flip wires around for the mafs 12v and ground while I wired it up per fsm with there connector but luckly I caught the mistake after I tried to start the car and it wouldn't fire up.
IACV, bought a new one since the new harness used a different connector type of one of the plugs
02 sensor, need a s14 since the WS need a 3 plug connector 02 vs a single wire like the s13 harness
TPS, swapped in a working on off my buddies car and still have it in. Getting .46v and closed light is on
ACC, checked its resistance and even threw it in the freezer to see it open and close simulating cold and warm starts.
Boost leak, put around 12psi and not a single leak besides around the z32 maf since it is blow through but I sealed it up.
Smoke test, no smoke leaked.
Timing, put on the dizzy about a million times and mechanical timing is dead on for the head. Can send pictures but I doubt timing would cause a lean condition but rather rich.
Fuel, replace FPR didnt help but got could finally hold pressure when car was off unlike old one, both held 43psi fine when running or primed, swapped in another walbro 255 from a buddies car and no differece, even put in a new fuel filter since I shaved/painted the engine bay.
Spark, ignitor works fine and all plugs are gaped and getting spark.
Checked grounds, everything 0s out for resistance.

This is how its running on start but dies out now https://youtu.be/qBbVtNIp5iQ

The last thing ive decided to check recently was the tune... Martin is normally good with his tune but for interest sake I got a copy of nistune and a chip burner. I get in it and over emails talk about things to change I think my latency is too low so I bump the latency from 650 to 800, started the car and no change. Loaded his tune again and bumped it to 1000 and no change. This is how that started I think on the 1000Us tune

https://youtu.be/tvrT4-q70Tg


Next I loaded the stock base image to see if I can at least get it running a bit better working off the stock tune, I resized the injectors to 1000cc, add z32 maf and increase the K value to 40% for the e85 and get a value around 28-30k which is about right. Didnt change anything else. Go to start it up and its idling! But now its to rich... and when I go to cruise with the 02 sensor off the car runs lean still in the 18s afrs... even on idle when its lean if I gently add throttle it leans out suddenly. The only time it gets right afrs from what I remember is under heavyish throttle like when I got out of first gear since I do have a pretty heavy clutch in the car but not on cruise.

This is how that idled https://youtu.be/YFSLPaKEZvM

What I noticed between the two tunes it the TTPMIN value. On the stock image its a lot higher while on Martin tune it is much lower which makes sense why its idling rich in my stock tune. So I copied the TTPMIN values off the stock tune and throw it onto the mail tune chips and they idle exactly the same, even running lean on cruise and light throttle.

Last thing I tried was since I get the car to idle maybe I can fix the lean cruise. So I play with the k value a bit, kept my latency at 650 since thats whats on my deadtime sheet and is about right for 1000cc. Now no matter how high I bump the k value the car runs exactly the same. Even when I put my k to the stock value of 39000 it still runs lean on cruise.... which doesnt make sense. If you have the same value as stock flowing 270cc it should be running stupid rich since they are firing the same pusle but the injectors are flowing/dumping about 4x as much fuel.

So this leads me to think this isnt tune related but still something external.. Im out of things to try, ive gone through basically everything. Last thing for me to try hope and pray is maybe I got a bad batch of injectors from Five0, ive heard mix reviews about them but there is no way they should be running so lean... It might be an electrical issue because you can get the injectors to run rich by changing the TTPMIN settings and even just taking the maf plug off throwing it into limp mode. I forgot if I checked injector voltage running but my battery gauge shows 14v when car is running and when key is on the injector plugs are getting 12v.

Anyone have any ideas?? Going to contact five0, try get hold of some stock injectors, increase the base tune for e85 and z32 maf then start the car to see if runs at least somewhat better. I checked other things like my brakebooster line, the taps in my manifold where I deleted the pcv runners. Im running a VTA system with a catch can, the pcv valve on the block is open and a line leads to a catch can along with a line off the valve cover to the catch can where it has another port to VTA, its mainly there to keep the engine bay clean and make things look neat. Another thing could be ecu related? When I wired my maf the fsm way I did burn a pin on my original ecu ignition pin out, I got another ecu and swapped the daughterboard over and everything checked fine. Another thing I noticed in my harness is feedback from this black/white wire which leads to the maf and gives the ecu power. I did a whole post about it but seems like its a normal thing. The relay is there for the wire to get constant 12v switch rather than run off ignition 12v.

http://zilvia.net/f/showthread.php?t=637393

Im out of options... I have no idea what else to check.

unex
Posts: 78
Joined: Sat Aug 06, 2011 6:59 am

Re: Lean issue Headache. Have tried EVERYTHING

Postby unex » Wed Dec 28, 2016 5:37 am

looks like you dont have right tuner and this is your problem. Good tuner will not send tunes via email. If he is remote, at least he would connect via remote desktop. Engine from engine very different, especially when we start talking about 1000cc, e85 and other modifications. It needs proper tune job. Also i am not sure if you understand what are you doing with tune.
First thing is that injector resize in software is only for reference and car have to be tuned properly.

ihatemy240

Re: Lean issue Headache. Have tried EVERYTHING

Postby ihatemy240 » Wed Dec 28, 2016 9:09 am

unex wrote:looks like you dont have right tuner and this is your problem. Good tuner will not send tunes via email. If he is remote, at least he would connect via remote desktop. Engine from engine very different, especially when we start talking about 1000cc, e85 and other modifications. It needs proper tune job. Also i am not sure if you understand what are you doing with tune.
First thing is that injector resize in software is only for reference and car have to be tuned properly.


Martin at Rs. Enthaphy has great track record with tunes, the whole reason I stuck with doing it off the stock ecu was to get a tune for these 1000cc and then later take a drive up to him once everything is broken in and dialed since its a good couple hours away. There is no point in going standalone till I shoot for major power and flexfuel, im happy with 350-400whp with my setup. There isnt many nissan guys down here is south FL who have a good track hisory. Its mainly honda/v8s, the nissan scene has been dead the last couple years and everyone who is basically stock power is running his tunes just as thousands of others do in the country with no issue. The big hp cars are done down here are at huge shops with 2-3k standalones, there is no one that still messes with stock ecu tunes.

I agree it needs a proper tune job but regardless it doesnt take a rocket scientist to understand the basic mechanics especially if im just trying to do a base tune which tuning doesnt seem to be this issue here. Regardless of different engines react, I shouldnt be having a k value the same as stock running injectors 4x the size and have it still run lean on idle/cruise. I know the resize gets you in the ballpark and when ive referenced and asked other tuning guys on ka groups you normally have a value between 20-30k. I even tried slapping there tunes in for 720cc and resizing it which doesnt change anything at all. I even looked on her for just about every ka post and non have had a crazy high k value to get it stoich around cruise.

There isnt much tuning wise that can fix the lean reading/dying, its just a mask to hide the real issue. You should really have the TTPMIN as low as you can if everything else in the tune is setup right with the k value, maps and latency, you shouldnt have an use messing with it.

K value is at stock value, o2 is turned off, all other value are stock so shouldnt be any funky business as far as idle goes, cranking is a bit off on stock tune on mail tune chips its perfect, latency should always be off the deadtimes sheet from manufacture and for 1000cc 650Us seems about right looking at other injectors. Im getting no codes in nistune or off the ecu light.

unex
Posts: 78
Joined: Sat Aug 06, 2011 6:59 am

Re: Lean issue Headache. Have tried EVERYTHING

Postby unex » Wed Dec 28, 2016 5:47 pm

I dont see any reason to be lean except tune. Ok, few things for you to think about:
1. I usually find that for 850-1000cc injectors latency works best in range 800-900. In some cases even around 1100. Never ever lower than 800.
2. Change K value until fuel target table afr values matches real afr on mid load. Not on cruise, but at least with 7psi.
3. After that, fine tune injector latency to match target afr on table while car on idle. Lambda feedback must be turned off. BTW lambda feedback should be off whole time until tune is finished.
4. If K value is way off stock, you need to adjust load axis. I always adjust load axis.
There are other issues when K value is way off, but for your setup I think it should not exceed 40% from stock and you should be fine.
5. In some cases you need to adjust MAF table if you want perfectly match fuel table afr to real afr. Especially low load and cruise. But its not necessary if you are ok with target afr table mismatch with real afr.
6. After you do changes press burn button to make sure that changes is written to ecu.
7. You will get more help if you give some logs and/or even tune.

ihatemy240

Re: Lean issue Headache. Have tried EVERYTHING

Postby ihatemy240 » Thu Dec 29, 2016 5:45 am

I can do a log, but going to just try throw in my buddies stock injectors and load the stock tune with z32 maf. If it runs some what richer then i got dud injectors.

1) I tried up to about 1000 for the latency and no change in idle.
2)I can try do that if it richens up following the other steps.
3) I have 02 feeback and everything else turned off just as the guide shows.
4) If bumping up the stock k value +-%40 doesnt richen the car up then I go change up the TP scales which im assuming thats what you mean by load axis.
5) I thought about messing with maf table but my z32 voltage is within spec. Key on its .5v and idling its 1.2v I could try lower the table to see if that richens it up a bit.
6) Im on a chip board so I just burn the chips and pop them into the daughterboard, if the car is fixed I'll be ordering the nistune daughterboard since swapping chips is such a pain.
7) I'll try do a log friday when im off, going to get stock injectors tomorrow.

Matt
Site Admin
Posts: 7857
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: Lean issue Headache. Have tried EVERYTHING

Postby Matt » Sat Dec 31, 2016 10:05 am

Okay trying to summarise this since it is a massive post ... and missing a copy of the tune file and log file

Stock motor running 720cc e85 and z32 blow through (runs fine)

Changes:
Rebuilt motor, 1000CC injectors fitted same time, new tune E85

Issue wiring into my new WS since they decided to flip wires around for the mafs 12v and ground

Why were there wiring changes made? Does the MAF voltage work fine? About 0.4V not start, 1V for idle

but for interest sake I got a copy of nistune and a chip burner

Okay so you are not running a Nistune board and I checked your email address for a software licence but you dont have one showing as purchased so I cannot provide technical support. Please contact me via email if you have a licence key


Return to “Type 3/4/5”

Who is online

Users browsing this forum: Bing [Bot] and 2 guests