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View Full Version : New Question (Dyno inside) STILL LEAN?



jclark462
02-10-2006, 03:31 PM
Running lean on the Dyno, http://img435.imageshack.us/img435/6606/gtdyno25yg.th.jpg (http://img435.imageshack.us/my.php?image=gtdyno25yg.jpg)

Setup..
S13 Redtop
GT2871r .86
JWT S4's
DW 740cc injectors
Z32 MAf
Greddy Intake Mani
Walbro 255 lph
Enthalpy tune.

I just need some places to start looking. I know my TPS is bad could that have caused this to be that lean? BTW this was at 13.7 PSI.

Thanks
Justin

Here is the plugs, Starting with number 1 from left to right. let me know what you think. Thanks Again for all the input.
http://img105.imageshack.us/img105/8848/plugs0gd.th.jpg (http://img105.imageshack.us/my.php?image=plugs0gd.jpg)

*******UPDATE**********
So I am stil waiting on my new tune. Scott must be SUPER BUSY!!!! I have a question. Looking at my dyno I think if I just get an adjustable FPR and bump up the base pressure a bit, it would fix my problem for now. My question is would it be safe to do? Does anybody know how much to turn it up? Thanks for all the help.

S15xedS13
02-10-2006, 03:39 PM
You could always use a SAFC to help enrichen it in specific areas, or you coud get an adjustable fuel pressure regulator and increase it across the board.

jclark462
02-10-2006, 03:41 PM
Yeah, but Scott tuned it for this setup, it's gotta be something I did.

Nikeboy355
02-10-2006, 03:52 PM
Yeah, but Scott tuned it for this setup, it's gotta be something I did.


Wow... That's when you know you have a successful business running...

jclark462
02-10-2006, 04:09 PM
Yeah, but Scott tuned it for this setup, it's gotta be something I did.


Wow... That's when you know you have a successful business running...



Yeah when was the last time we saw Scott mess up? That's how I know it is me.

240Shorty
02-10-2006, 04:26 PM
It might just be the long ass day i had at work today but if im not mistaken your tq/hp dont cross at 5250? Thats weird... http://forums.freshalloy.com/images/graemlins/confused.gif

TS4l
02-10-2006, 04:28 PM
Being a mail-order tune I do see that it might not be perfect but Scott's tunes usually are near perfect unless something is wrong with the setup. When I got mine it was rich and I thought for sure it was the tune, however once I fixed all the problems I found with my setup it was dead on.

What injectors are you using? Is it possible they aren't flowing as much as they are rated for? Where was the wideband, was it a sniffer wideband?

I wouldn't run it hard until you fix the problem or get a re-tune just to be safe. I'd hate to see you hurt your engine. Scott's always good with fixing it if its the tune but I would guess the only way the tune is that far off is if the injectors are not correctly rated or the fuel pressure is low.

jclark462
02-10-2006, 04:32 PM
Being a mail-order tune I do see that it might not be perfect but Scott's tunes usually are near perfect unless something is wrong with the setup. When I got mine it was rich and I thought for sure it was the tune, however once I fixed all the problems I found with my setup it was dead on.

What injectors are you using? Is it possible they aren't flowing as much as they are rated for? Where was the wideband, was it a sniffer wideband?



Injectors are 740cc Deatchwerks. he tried a sniffer first, but he said it kept getting clogged so we removed my o2, and put the wideband into the stock hole.

TS4l
02-10-2006, 04:35 PM
So was your 02 not hooked up? I know an ECU shouldn't use the 02 at WOT but I am just curious. I would try and check for vacuum leaks after the MAF, fix the TPS sensor and check fuel pressure unless you already know that.

cyanide
02-10-2006, 04:36 PM
what is your base fuel pressure?

jclark462
02-10-2006, 04:38 PM
So was your 02 not hooked up? I know an ECU shouldn't use the 02 at WOT but I am just curious. I would try and check for vacuum leaks after the MAF, fix the TPS sensor and check fuel pressure unless you already know that.


Yeah the o2 was disconnected. I did a boost leak test before i had it dyno'd, I fixed a couple of leaks. I am currently looking for a new TPS, and I don't have a fuel pressure gauge.(Maybe it's time to look into one???)

TS4l
02-10-2006, 04:43 PM
Only thing I could see doing this are low fuel pressure, low flowing injectors but Dave's injectors always seem right on, a bad MAF or leak between the MAF and turbo, or the tune is off. I'd think fuel pressure, bad tps, or MAF problem before the injectors or tune being off.

jclark462
02-10-2006, 04:45 PM
I have the TPS unhooked because I know it is bad. I still have the stock FPR. Is it time for a gauge?

TS4l
02-10-2006, 04:52 PM
I think the guage is a great tool to help find problems, or atleast eliminate that. You can buy one from Summitracing for $16 and an adapter or get a SARD FPR and install the guage in that. Its atleast a place to start. I'd get a new TPS sensor too. I beleive the TPS sensor signal is used for full throttle enrichment but I am not 100% on that. I would also talk to Scott, he e-mailed me and said he is back in the loop and able to respond quicker now.

hybridynamics
02-10-2006, 05:02 PM
first thing i would see is what fuel pressure scott has it tuned for, and what fuel pressure you are running. next i would go to another dyno, or even use another wideband on the street and see if possibly the dyno's sensor is going bad. If it is still that lean, then definitely crank the fuel pressure or get it retuned.

I'd definitely get your TPS sensor fixed, although it probably shouldn't cause it to run lean, if anything, they should be set up to richen it up when there is a sensor problem.

jclark462
02-10-2006, 05:05 PM
Yeah I thought about emailing him, I just don't like taking up peoples time, with something that is my fault. Scott is a really nice guy, but I'm sure he has 600 other people emailing him about probs that aren't his. I don't want to add to the list if you know what I mean.

turboka24
02-10-2006, 11:24 PM
It might just be the long ass day i had at work today but if im not mistaken your tq/hp dont cross at 5250? Thats weird... http://forums.freshalloy.com/images/graemlins/confused.gif


sure it matches up. look at 5252 and the hp and the tq are the same in numbers, just the the numbers on the side move at different intervals so the lines dont cross, but the actual numbers do.

gatecrasher
02-11-2006, 08:16 AM
Im with hybridynamics on trying another wideband in the car. a car that lean should have audible detonation up top more thank likely. Have you made any WOT pulls and then pulled the plugs immediately after?

Fred_Allen_Burge
02-11-2006, 09:32 AM
From what I've seen the TPS is used to detect sudden throttle opening so the computer can quickly inject a rush of fuel to prevent an enleanment. Also, it detects wide open throttle so the computer knows you just got serious and it can react accordingly.

allen

jclark462
02-11-2006, 10:34 PM
Im with hybridynamics on trying another wideband in the car. a car that lean should have audible detonation up top more thank likely. Have you made any WOT pulls and then pulled the plugs immediately after?


That is why I think it's the Dyno, It sounds great up top? I'm gonna pull the pugs in the morning. What should I be looking for? White?

jakerps13
02-12-2006, 02:26 AM
Im with hybridynamics on trying another wideband in the car. a car that lean should have audible detonation up top more thank likely. Have you made any WOT pulls and then pulled the plugs immediately after?


That is why I think it's the Dyno, It sounds great up top? I'm gonna pull the pugs in the morning. What should I be looking for? White?



Mostly white or gray and premature wear if lean. Optimally there should be a tan color evenly distributed around electrode and insulator.

gatecrasher
02-12-2006, 05:58 PM
warm the car up, take it for a WOT pull right up the street and back.......try not to cruise at part throttle for any length of time. pull the plugs. If the car is as lean as your dyno chart suggest....the ceramics on the plugs will be WHITE. possibly with small "pepper" specs on them if the car is detonating.

jclark462
02-13-2006, 01:37 PM
New Pics!!!

ItzGenX
02-13-2006, 02:57 PM
Those plugs don't look as lean as the graph says. Maybe the dyno wideband is the faulty thing here. That or you have a leak in the exhaust, throwing the readings off.

killjoy
02-13-2006, 03:24 PM
Thats what I thought. 1 looks a little lean but the others aren't bad.

jclark462
02-13-2006, 03:49 PM
The color on the number 1 isn't even that white it is more of a coffee color. The pics are crap cause I had to take them quick(i'm at work). I am going to set another dyno session for tommorow and see what that one says.

TS4l
02-13-2006, 05:09 PM
Thats what I thought. 1 looks a little lean but the others aren't bad.


Exactly what I was thinking. Looks like timing might be slightly off, but could also just be the pictures, its hard to read spark plugs from pics. Good luck on the next dyno run, I would think you would hear it if it was that lean, as said above check for exhaust leaks. Hopefully the wideband was just messed up.

S15xedS13
02-13-2006, 06:01 PM
I would check it with a good TPS. The TPS is a load sensor and helps the ECU enrichen the mixture when a WOT condition is present.

jclark462
03-02-2006, 02:51 PM
I went to the dyno again today, This time with the TPS connected, Fuel pressure gauge, LM-1 Wideband, and the Dyno Wideband. Long story short my rings are shot. I only out down 278 whp. This was at the same boost I ran the first time. Base Fuel pressure was 43.5 and rose with boost. WOT @ 13 psi was in the 14.8/1 range for the Air Fuel ratio. WTF? I don't know what else to do.

1mns13
03-04-2006, 04:05 PM
I went to the dyno again today, This time with the TPS connected, Fuel pressure gauge, LM-1 Wideband, and the Dyno Wideband. Long story short my rings are shot. I only out down 278 whp. This was at the same boost I ran the first time. Base Fuel pressure was 43.5 and rose with boost. WOT @ 13 psi was in the 14.8/1 range for the Air Fuel ratio. WTF? I don't know what else to do.


Are you saying both widebands read the same? '
I'd also suggest running heat range 7 plugs.

nissanfanatic
03-04-2006, 06:01 PM
That torque curve looks a little too good for there to be any issues... If it were in fact that lean, pre-ignition/detonation would have eaten that curve up. AKA, it would look like crap.

Do you have any exhaust leaks? My local dyno wideband also reads very lean....

Also was there a slight boost spike?

jclark462
03-04-2006, 08:18 PM
It is def Lean. I tested two widebands, and there are no exhaust leaks. I screwed up and kept driving, and now my rings are shot. When I went to the dyno on thursday I only put down 280 at the same boost, and my dipstick came out. http://forums.freshalloy.com/images/graemlins/90.gif I should have stopped driving after the first dyno, but I was dumb and didn't. http://forums.freshalloy.com/images/graemlins/banghead.gif

jclark462
03-04-2006, 08:20 PM
I forgot to add I already talked to Scott. He thinks the injectors are not flowing what they are rated, and is sending out another tune. Impeccable service as always.

janders211
03-12-2006, 09:25 AM
Did you test the injectors? Were they new? Why do you think they are the problem, i.e. were you sent the wrong set or what?

jclark462
03-12-2006, 11:10 PM
Did you test the injectors? Were they new? Why do you think they are the problem, i.e. were you sent the wrong set or what?


Look up for your answer.

janders211
03-13-2006, 03:07 PM
Did you test the injectors? Were they new? Why do you think they are the problem, i.e. were you sent the wrong set or what?


Look up for your answer.



I must have missed where you said they were new or not. If they were new they should have come with a flow sheet. And if the injectors are bad- I'm sure they'd send you a new good/correct set. I'd want to get what I'd paid for before I got a retune to compensate?

jclark462
03-13-2006, 05:37 PM
Yeah I have been thinking about emailing Dave. I just want to see if the new tune fixes it first. I am still waiting on Scott, he must be super busy. I don't like paying for 740cc's and then getting 650cc's. If that were the case. I'll find out soon enough. Here is a chart I did the first dyno session but at 15 psi.

http://img142.imageshack.us/img142/8549/gtdyno4nl.th.jpg (http://img142.imageshack.us/my.php?image=gtdyno4nl.jpg)

jclark462
04-05-2006, 07:42 PM
*******UPDATE**********
So I am stil waiting on my new tune. Scott must be SUPER BUSY!!!! I have a question. Looking at my dyno I think if I just get an adjustable FPR and bump up the base pressure a bit, it would fix my problem for now. My question is would it be safe to do? Does anybody know how much to turn it up? Thanks for all the help.

Alpha
04-05-2006, 08:05 PM
Dynojet sniffers read a little lean but in your case you are actually running too lean as you stated later. I know Scott offline and have never known him, even mailorder, to tune a car to those A/F ratio(s). Something is wrong. I would send the injectors to RC Engineering to have them cleaned, balanced and calibrated. They will send you a flow sheet back with them.

http://www.rceng.com/service.htm#INJECTOR

jclark462
04-05-2006, 08:23 PM
Dynojet sniffers read a little lean but in your case you are actually running too lean as you stated later. I know Scott offline and have never known him, even mailorder, to tune a car to those A/F ratio(s). Something is wrong. I would send the injectors to RC Engineering to have them cleaned, balanced and calibrated. They will send you a flow sheet back with them.

http://www.rceng.com/service.htm#INJECTOR



Well i have emailed him back and forth(a month ago) and we agreed to try a new tune before sending the injectors out. The injectors are new from Deatschwerks. Scott was supposed to mail out a tune that week. But I am still waiting for it???

Alpha
04-05-2006, 08:35 PM
I know Scott is busy as Hell but he will come through. Just remind him now and again. Worth the wait. Have you performed a compression test? What's your base fuel pressure?

jclark462
04-05-2006, 08:41 PM
I know Scott is busy as Hell but he will come through. Just remind him now and again. Worth the wait. Have you performed a compression test? What's your base fuel pressure?



Yeah I have emailed him a couple of times, with no response. Fuel pressure is good. Compression was good till I drove the car not knowing it was really lean. http://forums.freshalloy.com/images/graemlins/banghead.gif

Alpha
04-05-2006, 08:43 PM
I know Scott is busy as Hell but he will come through. Just remind him now and again. Worth the wait. Have you performed a compression test? What's your base fuel pressure?



Yeah I have emailed him a couple of times, with no response. Fuel pressure is good. Compression was good till I drove the car not knowing it was really lean. http://forums.freshalloy.com/images/graemlins/banghead.gif



What did the base fuel pressure read when you checked it?

jclark462
04-05-2006, 08:48 PM
Base pressure 43.5psi and rises with boost.

Alpha
04-05-2006, 08:55 PM
Base pressure 43.5psi and rises with boost.



Well. Let's see what the new tune does for you when you get it. Good luck with the compression test as well.

jclark462
04-05-2006, 09:00 PM
That's just it. i don't know when I'll get the new tune http://forums.freshalloy.com/images/graemlins/beatdeadhorse5.gif. That's why I am thinking of the Nismo FPR. And raising the base pressure. Will that work?

Alpha
04-05-2006, 09:07 PM
If I run into Scott I will try and remind him. Doubt it due to his schedule.

Enthalpy
04-05-2006, 11:28 PM
hey man.

just finished writing your new program. have it going out for next day delivery to you on friday. you will recieve a e-mail from UPS with your trackng number to your paypal e-mail address.

thanks.

jclark462
04-06-2006, 09:06 AM
hey man.

just finished writing your new program. have it going out for next day delivery to you on friday. you will recieve a e-mail from UPS with your trackng number to your paypal e-mail address.

thanks.



Thanks Scott.
Justin

sorce
04-08-2006, 12:20 AM
Base pressure 43.5psi and rises with boost.



I thought base pressure was supposed to be at 50 PSI. That's what I'm currently running with Scott's chipped map.

forcefedS13
04-08-2006, 10:45 AM
43.5 is supposed to be the base fp. at least thats what ive ALWAYS been told.

cosmoworks
04-10-2006, 03:44 PM
Base pressure 43.5psi and rises with boost.



I thought base pressure was supposed to be at 50 PSI. That's what I'm currently running with Scott's chipped map.



Scott indicated (http://forums.freshalloy.com/ubbthreads/showflat.php?Cat=&Board=UBB9&Number=68060249#Post6 8064015) that he typically tunes for 49.5 psi pressure across the injectors. Stock fuel pressure across the injectors is 43.5 psi.

Gauge pressure at the rail rises with boost on a 1:1 ratio, but the differential pressure across the injectors doesn't change regardless of boost (unless you run a rising rate regulator),

-Cosmo

Alpha
04-16-2006, 12:33 PM
Did you get this taken care of?

jclark462
04-16-2006, 04:49 PM
Did you get this taken care of?


Well i got the tune friday. Went to the dyno tuesday. It's still lean?? I am starting to think it is something with my harness or my car???
Old Tune.. around 11.5 psi
http://i80.photobucket.com/albums/j196/jclark462/th_GtDyno2.jpg (http://i80.photobucket.com/albums/j196/jclark462/GtDyno2.jpg)


New Tune... around 11psi
http://i80.photobucket.com/albums/j196/jclark462/th_DSCN1813.jpg (http://i80.photobucket.com/albums/j196/jclark462/DSCN1813.jpg)


Death to my CAR!!! http://forums.freshalloy.com/images/graemlins/banghead.gif http://forums.freshalloy.com/images/graemlins/beatdeadhorse5.gif http://forums.freshalloy.com/images/graemlins/2.gif http://forums.freshalloy.com/images/graemlins/auto.gif http://forums.freshalloy.com/images/graemlins/4.gif

jclark462
05-27-2006, 09:47 PM
Just to update everybody. Scott's tune was spot on from the get go. The problem ended up being the engine harness. I put in a new harness and the car runs perfect. So I have another block going in by wednesday, and I will be going back to the dyno again. Thanks to Scott and now Chris for all there patience and help. You guys rock.

SlowCoupe
05-28-2006, 01:17 AM
i'm just curious but what in the harness can cause your engine to run lean?

jclark462
05-28-2006, 07:39 AM
i'm just curious but what in the harness can cause your engine to run lean?

Something was making the #2 and #3 injectors to fire very erradictly. The car ran like crap for a long time, but I thought it was sensors or something I did. I have had that harness for about 4 years. It was always fine on the t25, and when I upgraded to a t28. I guess the bigger injectors exxagerated the problem? I am not sure. Maybe someone who knows more about it can chime in. It is is weird having a car that runs like stock though. It's awesome.
I love this car all over again.