# MegaSquirt, Problem Stalling out on decel.



## Jones84 (Sep 6, 2007)

Ok here is my issue. I just spent a lot of money getting my 84 GTI with a built 9A tuned on the dyno. It runs great and made sweet power 183.5whp 176tq, How ever for some reason when i am coming off a hard acceleration or WOT it stalls out on the deceleration. i have tried a few things but nothing is working. 
I am NOT running a IAC or stepper valve.
This issue is making very hard to make a clean shift. When i am driving its a pain.
When i am in the shop and do a 6k rev, once i take my foot off it just dies. It always starts back up. It idles just fine and under normal driving its ok. 
But under any hard (fun) driving it revs and i push in the clutch and it dies. 
If any one can help or has had this problem, Any help would be great. 
Thanks


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## Prof315 (Jan 5, 2009)

post up a copy of your msq so we can take a look at it .


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## Jones84 (Sep 6, 2007)

How?? I have a copy of my hole MSQ saved, but i cant get it on the here. If you can help me out i would be happy to post.


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## Prof315 (Jan 5, 2009)

Jones84 said:


> How?? I have a copy of my hole MSQ saved, but i cant get it on the here. If you can help me out i would be happy to post.


Go to MSruns.com, sign in/create an account, post it there and put a link to it here.


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## Jones84 (Sep 6, 2007)

http://www.msextra.com/forums/download/file.php?id=17410

Here it is, let me know if you see something wrong


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## Jones84 (Sep 6, 2007)

TTT, any one got any input?


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## need_a_VR6 (May 19, 1999)

Change decel fuel amount to 100% under the accel section and see if that fixes it.


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## Prof315 (Jan 5, 2009)

need_a_VR6 said:


> Change decel fuel amount to 100% under the accel section and see if that fixes it.


Thanks Paul! Been busy busy at work & home, not much free time past few days.


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## Jones84 (Sep 6, 2007)

I will try it that and let you know, Thanks..


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## Jones84 (Sep 6, 2007)

Ok So i tried to up the decel to 100% and i raised my timing at 900 rpm up a few points, Still no change. i am running with my ego OFF, when its on it stumbles a little. not sure what that's all about.
Any other options?? I am pulling my hair out with this one...


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## need_a_VR6 (May 19, 1999)

Post up a datalog of the behavior, it'll be much easier to figure out.


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## Jones84 (Sep 6, 2007)

Ok so i did some longing and here are 2 of them. let me know what you think. Thanks again

http://www.msruns.com/download/file.php?id=6223

http://www.msruns.com/download/file.php?id=6224


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## need_a_VR6 (May 19, 1999)

You need another VE bin around max decel, something around 10kpa would work. Then try and get those low kpa VE's tuned in.

This isn't usually an issue, those running /Extra can turn on decel fuel cut with a few parameters (tps and map thresholds, time delay, etc).


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## Jones84 (Sep 6, 2007)

So i changed the bottom bin to 20kpa. it did not seem to make a difference. so i took 2 datalogs wile in the shop so i could show you what its doing.:banghead: 
http://www.msruns.com/download/file.php?id=6225
http://www.msruns.com/download/file.php?id=6226
so i rev it a few times and as soon as i hit 5k it wont stop at idle, just goes right past it and dies..:banghead:


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## need_a_VR6 (May 19, 1999)

You try adding fuel to those new bins?


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## Jones84 (Sep 6, 2007)

Yes i did add to the 20kpa bins. When i am at idle my A/F should be around 13 to 14. It still craps out.
I am going nuts.


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## need_a_VR6 (May 19, 1999)

What are you using for an air bypass and what is your hot idle rpm?


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## ValveCoverGasket (Mar 20, 2002)

where are you pulling your MAP signal for the ecu from?

i did think once on accident with a digi1 install... and was pulling the ecu MAP signal from ahead of the throttle. seemed to run fine when the throttle was open, but as soon as the throttle shut, the signal would go close to atmospheric and kill the engine almost instantly :laugh:

took a couple days to figure out but it was really frustrating because it would sometimes idle... if you closed the throttle reeaaaallly slowly.


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## Jones84 (Sep 6, 2007)

I am pulling the map and the Fuel pressure reg off the back of the throttle body. 
The only other place i can grab it from is the big brake booster hole. 
You know come to think a bout it i don't remember this problem before i but in the new FPR? not sure why it would make a difference, i was running a stock 3bar on the rail before. Now its adjustable and on the inner fender..


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## Prof315 (Jan 5, 2009)

need_a_VR6 said:


> What are you using for an air bypass and what is your hot idle rpm?


X2 I know you have no idle valve but what is your hot idle rpm?


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## Jones84 (Sep 6, 2007)

It is at 1100rpm to 1200rpm, I know its a little high but its so it will idle when cold at 900ish.
sometimes it hunts for a sec before it lands, like 900, 1300, 2 or 3 times then it lands on 1100ish.

I tool and separated my FPR from the MAP and it did not help, I am going to switch them next and run the MAP out the lower intake manifold and the FPR on the throttle body. i am just worried about how far i have to run the line from bottom right lower intake (old idle valve spot) and go to the glove box. 
This issue started when i payed (more than i should have) to get it tuned on the dyno. They said it was because i don't have a Idle valve, but it never did it before. thats why i think its a setting in my MSQ. But what do i know:screwy:

Sorry i missed a post, I am not running any air bypass, I don't think. No idle valve just cone filter intake pipe IAT and Throttle body. O ya and its set up for Ram Air. Cut hood and scoop. It works great.


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## need_a_VR6 (May 19, 1999)

Can you take a log and post the msq with the new load bins in it. All your other logs have a really low pw in that decel area that it doesn't seem to want to recover from.


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## Jones84 (Sep 6, 2007)

Sure thing, It will be tomorrow I have my son and his car seat wont work with 5 points. LOL
It will show that i changed the low KPA to 20 and raised the VE up to compensate around 2k 
I think that was all the changes that i needed to make?


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## Jones84 (Sep 6, 2007)

Ok here are 2 new data logs and my MSQ. It did some weird stuff wile driving today, it was jumpy like a hesitation.
So when i was looking at the logs i saw that my dwell is jumping i think at the same time. Not sure if the two are related or not. take a look at the and let me know what you think.
this is my currant MSQ the one that i am running now.

http://www.msefi.com/download/file.php?id=11000
http://www.msefi.com/download/file.php?id=11002
http://www.msefi.com/download/file.php?id=11003


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## need_a_VR6 (May 19, 1999)

There's nothing obvious other then you really need an even lower ve bin something around 10kpa. Though I don't see AFR logged this time.


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## Jones84 (Sep 6, 2007)

No i have it turned off for tuning, i am using my Wide band Gage with the EGO off. So you think i should change my 40 to a 30 and my 20 to a 10? If that going to help i will give it a try.


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## need_a_VR6 (May 19, 1999)

Yes your min load bin should be about your min vaccum which is 12.x kpa in the logs. It's hard to tell what your motor is grumpy about without afr so get that back into the MS!


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