dyno now car turns off

[eclipsemustang]

i just had my car on the dyno to tune it and long story short we did about 20 pulls and after all of those we finally realized my safc II couldnt compensate for the 650's, so im still running rich but now my car will shut off after i get into boost than push the clutch in.
ex.) if i take off and boost and than get up to speed and want to coast so i push in the clutch instead of going back to idle my car shuts off, but if i just shift and dont coast my car runs fine. anyone have any idea whats going on?

 

[10_seconds_2luv]

How does the car idle in neutral?

 

[robbo185]

let me guess, your bov is vented to atmosphere

 

[RadDsm]

Maybe you are "flooding" your motor. You said you are running rich, maybe you are dumping too much fuel and its not burning. Have you checked your plugs? Or try a boost leak test?

 

[eclipsemustang]

the car idle's fine in nuetral, maybe a little higher than normal but nothing crazy its probably at about 800-900 at times instead of about 700-750, and no i am not venting it to the atmosphere. i havent checked my plugs, but it shouldn't be a boost leak we fixed those on the dyno.

 

[mikelv]

Okay, since your grammar was a little less than punctual, (which I can understand because you're probably pissed over your DSM) let me start by asking if I understood you correctly. You made a bunch of Dyno pulls and your AFC wasn't working properly. (Last time I checked, an AFC should handle 650cc injectors just fine). Now when you push in the clutch to drop the transmission into neutral when driving the car stalls out on you? Okay let's go through a series of questions to narrow this down, because those symptoms can be caused by numerous problems.

Are there any other known modifications to the car besides what you have on your Profile page?

If so what are they, and have any been done since the Dyno run. Rumpy cams can cause this among other things.

Is the AFC wired properly?

Double check and make sure first of all. I know it's been a while for me on the AFC, but I'm more than positive they can handle that size fuel injector. Check those wires, and check that fuel system, top to bottom for any visual damage, or shorts. Also, check your Mass Air Sensor for any visual damage or disconnections. Ensure your air/fuel systems are working and functioning properly.

Boost/Vacuum Leaks

This is always a big one, especially after you've been driving the car hard. Check all those pipes you have for leaks. Run a boost leak test on the system, and check all your vacuum lines to ensure none are disconnected, torn/frayed. 9 times out of 10, this is the cause.

You said the car shuts off? Does it stall, or shut off?

That is a major difference, make sure you clarify.

Do you have any CEL (check engine light) codes popping up?

Sometimes the ECU cannot sense vehicle speed if there is an open circuit in relation to the speed sensor unit. Basically when the ECU cannot process vehicle speed, it can have a difficult time determining engine load, and RPM. Make sure all your sensors are functioning properly and there are no blown fuses, or open circuits in the system. More culprits can include your ISC, FIAV, and TPS. There is ample information on this site, along with the VFAQ's on how to test and set those circuits.

Does the car idle, or do you have the same kind of problems? Have you properly set your base timing? If so what is it?

If your base timing is not correctly set in accordance to your setup, then you can also run into idle problems, cruise or idle. Also, what RPM does the car idle at, and does it hold on it's own. If everything else is ok, you could probably just need a simple tune and a turn of the BISS. (Base Idle Set Screw) Try backing out the idle screw and see if you can get a consistant idle. Also, how exaclty does the car idle? Does it hold, or fluctuate?


Tuning on the car, rich tuning?

Post your logs from the last Dyno run, along with your AFC, Boost, and Octane settings as well. Those are the most helpful pieces of information. We can determine what is happening from understanding certain values coming from the ECU. Let us know what you have for logging equipment, if any. Also, pull the spark plugs; I want to see what they look like. They can tell us more than any electronic device.


Go through these questions, and try and eliminate the possibilities, from there we'll see where we stand. Don't worry, this is a pretty simple and common problem, try some searches, you'll find help. Good Luck.

 

[eclipsemustang]

1.) no there are no other mods on my car than in my profile. (i did just get an AFPR but its uninstalled)
2.) I believe the SAFC is wired properly but im going to reinstall it because it keeps randomly turning off, so maybe i have a bad SAFC
3.) I'm about 99% sure i have fixed all the boost/vacuum leaks. i can run another boost leak test though.
4.) I want to say turns off, because there is no sputtering at all it just simply goes all the way to 0 RPM's
5.) I have always had the CEL on, I should go get the code read
6.) My car idles just fine, its starts out maybe 850 rpms but drops to 750 where it normally sits.
7.) I dont have any info on the dyno, i didnt get any printouts or anything, but the boost was set at 20psi, running on 92 octane. and i still need to pull the plugs.

but the car runs normal,and boosts fine. but it does start funny because it stutters and goes right to 750 rpms instead of when i normally turn on and it goes to about 1500 and comes back down.

 

[beating4g63s]

sounds to me like either a boost leak somewhere, bad ground, or your running very rich, your safc should be able to work with 650s seems like the person tuning your car may not have known what they were doing, also I'd pull your cel just to see what codes they are.

 

[spyderturbo007]

Before you go re-installing the SAFC, pull the back off of the display and make sure the harness isn't loose. Also, post up all of your SAFC settings, because you can easily compensate for 650's with the SAFC. I ran that way for about 2 years before going with DSMLink. I'll need Sensor type, TPS trigger points, direction of the arrow, Ne points for both Hi and Lo maps and corresponding corrections factors.

Also, do you have an AFR trace from the dyno run, or perhaps a log of any of the runs?

Oh, and get that CEL code pulled!!!!

 

[Freerevving]

After making those dyno pulls you might have caused a seal to leak
1.check again for boost leaks
2. A bad Idle control valve will cause this problem when suddenly dropping from upper rpm's (3k and up)... happened on my talon and two other non-dsm's
3. if your AFC is blinking off there is definitely a problem there

HTH --Mac

 

[eclipsemustang]

here are the SAFC settings
Hi throttle is -50% all the way across
lo throttle is about -10% across
throttle is at Lo:10% Hi:60%
Nepoints are 800,1400,2000,2800,3400,4000,4600,5200,5800,6400,6800,7200
Dec.-air: Thr .2% Ne1: 10% Ne2: 10%
Sensor type is Karman
arrow is northeast

 

[someguyonline]

here are the SAFC settings
Hi throttle is -50% all the way across
lo throttle is about -10% across
throttle is at Lo:10% Hi:60%
Nepoints are 800,1400,2000,2800,3400,4000,4600,5200,5800,6400,6800,7200
Dec.-air: Thr .2% Ne1: 10% Ne2: 10%
Sensor type is Karman
arrow is northeast

hi throttle at minus 50% is bad!!car will run much more timing because of that, and the throttle lo/hi should be close to each other. the lo throttle corrections will only work under the tps % setting and the hi will only allow the corrections over that tps %. so basically you a gap between 10% and 60%, could be your issue

 

[spyderturbo007]

-50% is way to lean for 650's, so you need to stay out of WOT until you get the tune fixed up. TPS trigger points should be -30% and -70%. Decel air on our cars doesn't work properly, so put that back to default.

This is what I would do:

1. Set your high throttle map to -25% all the way across.
2. Set your FT's properly
3. Make a 3rd gear pull from 2.5k to redline and log timing, rpm, front O2 and airflow, then post up the log.

This guy has your tune all screwed up and if I were you, I would be pissed. I would also recommend a compression test before restarting the tune, just because you were running so lean durning the dyno session. We just want to be sure that there wasn't any damage.

Did he happen to tell you what AFR he was shooting for?

Oh, and pull that code with your logger.

 

[eclipsemustang]

i believe he said he was aiming for a 12.1:1 ratio. but his equipment said i was still running rich even after we did a pull at -40% we did one at -20% than -40% and he said it leaned it out a little but not much at all and i was still running rich. could there be something wrong with my SAFCII?

 

[mikelv]

Sorry, I haven't posted sooner, didn't forget about ya.

As someone else said those settings are a ways off. Let's take a minute to look at this.

The stock injector size for a typical DSM is 450cc. You have 650cc Injectors. If you do the math properly, it turns out that your injectors are approx 25 to 30% larger than stock. Now by no means is this a "set in stone" method, but it is a good starting point. So when you’re running your Air Flow Converter at maximum correction, (50%) there should be red flags going up. Who in the heck tried and tune this car for you? They obviously didn’t know what they were doing.

Now assuming that the wideband on the dyno wasn't screwed up, there is no way your car would run 12.0 or richer with a correction factor of 50% with 650cc injectors on that fuel and boost level. I just don't find that feasible. If all else is good which I doubt it and it takes a 50% correction factor to get at least a 12.0, then there is a problem in the AFC somewhere. Honestly, I’m starting to think this is tuning issue. That correction factor would make you seriously lean, which is seriously bad.

And to speak of it, 12.0/1 at that boost on pump gas will most likely detonate, depending on other factors. I wouldn’t run that lean on pump gas with any real boost pressure. You have tons of opinions on that, but I’m telling you that’s just me. Heck I won’t even run that close on race gas.

I would be very surprised if you didn't damage anything running multiple pulls at 20 pounds on pump gas, with that correction factor. If everything is working properly, there's no way your running a 12/1 ratio. You are way leaner than that.
As some mentioned, you need to run a compression test, and see if you are okay. If you’re not seeing what you want, then look into it….. You’re looking to get 180 across the board. If not then drain and change your oil at a minimum. Check the texture of your oil, look for signs of coolant. Check your coolant for signs of oil, make sure that Head Gasket is ok. I’m pretty sure you won’t find chucks of metal in your oil at this point, you’d def know that by now. Also, you need to pull the spark plugs and check out what is going on, spark plugs don’t lie.
You are way off on your AFC Settings as someone mentioned here.
Read the tech articles regarding AFC operation, and then read it again. Apply the knowledge in your own application. I’m not going to tell you how to tune your car…. That would be a waste of time. (You must learn that yourself)

http://www.dsmtuners.com/forums/art...c-mid-point-correction-factors-operation.html

http://www.dsmtuners.com/forums/articles-tuning-ecu/58403-definitive-piggyback-tuning-guide.html



Good Luck, keep us posted.

 

[someguyonline]

i believe he said he was aiming for a 12.1:1 ratio. but his equipment said i was still running rich even after we did a pull at -40% we did one at -20% than -40% and he said it leaned it out a little but not much at all and i was still running rich. could there be something wrong with my SAFCII?

i would ask for your money back and go find someone who has a better idea about whats going on, if your tuner is having this much trouble with a afc then they really shouldn't be charging for a tune.

 

[spyderturbo007]

12:1 on pump gas with no Meth is way too lean. Make sure you stay out of WOT until you get the tune straightened out, so you don't do more damage that has already been done.

 

[eclipsemustang]

i guess im lucky than because i have done 0 pulls at -50% only one at -40%

 

[CanadianTSi]

If your at -50 and still rich you have a big boost leak.

 

[mikelv]

If your at -50 and still rich you have a big boost leak.

I don't think he's saying this.

I'm thinking your okay, and just need tuning. If the tune was around 12.0 @ 40% correction. That's lean but sounds about right for 650's.

How "rich" was the car at 40% correction, did the guy tell you? Because 12.0is way too lean. If the car was running in the mid 11's ratio, then your pretty close, not rich.

But like somone said, if you max it out and your consistantley running rich, then it's boost leak, but I don't think your rich.

You need to go somewhere and get tuned before you boost the car anymore. And like I mentioned before dude, do another boost leak test.

 

[eclipsemustang]

i doubt i have a large boost leak because it spools up and holds 20psi easily, but i've decided to try and take this tuning into my own hands, Since this is the first time i've ever let anyone work on my car other than me and nothing went right, im now saving for a wideband 02 and a pocketlogger. Right now i would just like to know why my car turns off when i coast.

 

[mikelv]

i doubt i have a large boost leak because it spools up and holds 20psi easily, but i've decided to try and take this tuning into my own hands, Since this is the first time i've ever let anyone work on my car other than me and nothing went right, im now saving for a wideband 02 and a pocketlogger. Right now i would just like to know why my car turns off when i coast.

It's tuning man. Did you record those numbers at 40% correction?
It's hard to disgnosis a problem with tuning when you have no logs to post. No biggie, but next time just keep that in mind. You'll get a lot more helpful posts.
If the car was fine before the tune, and now it's messed up, obviously it happen during the tune.
Either you are leaking boost, running too rich/lean or have an electrical problem.
Think about it.....what does a car need to run properly?
Air, Fuel, and Spark, right?

If one of those systems aren't functioning properly, then your going to have stall problems, ect, ect...

Start with the simplest task, and eliminate possibilties.....just like the book says. 9 times out of 10, your not going to get much off the forums....you just have research and work hard and figure things out. It's the best way to learn. I can almost guarantee the shop manual has a comon problem listed for stall during coast, ect ect (You have a shop manual right??)

Just cause it's a DSM, doesn't mean it doesn't hold the same general principles as any other car. You'll figure it out.

Nothing on you man, but I'm tired of posts like this.
I'm going to write a diagnosis tech article for people to figure out basic problems. I mean it's too easy... just step back for a second, take a breath and think about it. You'll get it.

 

[Boosted97GSX]

This same problem happened to my friend. His car ran fine and boosted fine but if he let the rpm's go down fast after boosting or put his clutch in after accelerating hard and boosting his car died. It turned out to be his oxygen sensor. Check that out.

 

[kspharris]

Something you may want to try is removing or just disconnecting your AFC and don't forget that your injectors are larger also. Take them out if you have your stockers. Turn the boost down for the next couple of runs and see if it does the same thing. If it does then it may be the lightened flywheel, however that is considering that all is well with your car. Have you disconected your battery recently? My car had this problem twice after a battery disconnect. It has to relearn. Turned out I had a boost leak one time. I do suggest another boost leak test and compression test to see what shape your car is in. Oh yeah after those runs if it doesn't stall then add a component, then do some runs then add more boost and then your afc. Oh yeah again..right now after you get done reading this get into your car...go now....and drive to Autozone and get that code pulled...Good luck and hope that this helps.

 

[eclipsemustang]

I have a boost leak i just need to find out where it is, and i am going to get a new 02 sensor soon, and im looking for some logging equipment. so for now i'm either not boosting or driving my other car.