# Megasquirt, Accel. Enrichment spiking rich under cruise conditions...



## secondgen (Jan 9, 2004)

Trying to get my coupe tuned a little better, started with a base-map, tuned with megalogviewer to get a better tune and have been playing with the rest of the map manually doing some fine tuning.
I'm having trouble getting my acceleration enrichment to stop randomly spiking rich under low-throttle cruise conditions.
like so:








My Enrichment settings are:








And the fuel map is:








I can email the log and MSQ. or post on ms runs if someone wants to look through the whole thing. 
Going to have the car dynoed tomorrow, and trying to make sure its running well enough to do so. http://****************.com/smile/emthup.gif 
TIA
The car in question:


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## mk2dubbin (Mar 16, 2002)

increase your tps-dot threshold to 0.5 or more. unless youre itb'd or have a crazy motor - you may also find map based to be more useful.


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## secondgen (Jan 9, 2004)

*Re: (mk2dubbin)*

Decently high compressioned aba-bottom end with heavily worked 276* camed counterflow head with mustang throttle body
TB:








motor:











_Modified by secondgen at 12:45 PM 4-18-2008_


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## wvwjetta (Feb 20, 2005)

I know it doesn't help your thread, but thats a beautiful engine bay. I know a lot of people don't think much of 8v's but I do.
Practical, Simple and Clean. Nice work.


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## need_a_VR6 (May 19, 1999)

*Re: (wvwjetta)*

You sure the afr spikes are accel based? The tps signal looks pretty steady.. AFR dancing is pretty normal depending on your O2 correction settings.


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## secondgen (Jan 9, 2004)

*Re: (need_a_VR6)*

ego correction is off, and i know it's accel related because the accel indicator turns red when you watch the log, which happens to directly correspond with the spikes.
Want the log or msq, paul?


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## need_a_VR6 (May 19, 1999)

*Re: (secondgen)*

You can email me both, but I need your open and closed throttle adc as well. Take tps threshold WAY up to 5v/s and see if it makes a difference. Also, if you're trying to tweak using the log viewer turn ego correction on, it'll go much faster.


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## secondgen (Jan 9, 2004)

*Re: (need_a_VR6)*

I apologize, EGO correction was on, sent you an email, let me know if you need something else from me. http://****************.com/smile/emthup.gif


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## ValveCoverGasket (Mar 20, 2002)

*Re: (secondgen)*

i would suggest moving the threshold to something around 1-1.5 and moving your first table v/s value to something in the 4-6 range, then work your way up from there.
i think its just got some hair trigger sensitivity (that it really doesnt need) right now


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## secondgen (Jan 9, 2004)

*Re: (ValveCoverGasket)*

After the dyno and talking with some people and your posts, i think im going to try the MapDOT accel, see if it's any better, this throttle body's just REALLY sensitive, also moved my cam retarded another 3* so now im at a total of 6* Retarded, i wasn't making any power above 5800, and with my setup i think i should be making plenty up top (making 105 peak @ ~5500). the torque was quite surprising though (peaked 115 @ 4100).
Also have some fuel map issues, as the torque curve should've been smoother, but i dipped to almost 12.5 afr and it killed the power. I'll have a scan of the dyno sheet shortly...
retuning, and using pauls VR6 target afr's as a starting point for megalog viewer, i'll fine tune from there...i guess....








learning as i go. Anyone have a good spark map they car recommend? I really don't know where to start there...thanks for the help guys.


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## secondgen (Jan 9, 2004)

*Re: (secondgen)*


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## Shawn B (Nov 27, 2003)

*Re: (secondgen)*


_Quote, originally posted by *secondgen* »_ Anyone have a good spark map they car recommend? I really don't know where to start there...thanks for the help guys.

http://www.vintagewatercooleds...928.0
Timbo's posted his there about a third the way down the page.


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## secondgen (Jan 9, 2004)

*Re: (Shawn B)*

Wow, looks completely different than what i've got....hm...thanks


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## AlbertoB1 (Dec 29, 2007)

Quick help. I was getting my car tuned at a local shop. Well over the last month it's only gotten worse. They can't figure it out because they don't know what they messed up. They gave up unless I dish out big money for new hardware, that's another issue I will be deaing with. I will probably have to sue. Well now it's my turn, I have the latest version of Megatune but haven't hooked up to car yet. Car was running fine then when I got off work I tried to start it and it seemed like timing was way out of wack and my RPM needle was jumping all over the place, what could that be before I hook up my computer to cars MegaSquirt computer?
Sorry to jack your thread










_Modified by AlbertoB1 at 7:33 PM 4-19-2008_


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## secondgen (Jan 9, 2004)

*Re: (AlbertoB1)*

I have no idea what's wrong with your car, and i do suggest you make you're own thread concerning help with it. http://****************.com/smile/emthup.gif


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## Wraith04 (Jun 24, 2004)

*Re: (secondgen)*

What msq are you using now?


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## Wraith04 (Jun 24, 2004)

*Re: (Wraith04)*

I do have some more aggressive spark maps you could try.


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## secondgen (Jan 9, 2004)

*Re: (Wraith04)*

Your MSQ only worked to get this started, motor's so different, it's basically a new map, but it's spark map i think is your original maps spark table. i have your aggressive map i think....


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## need_a_VR6 (May 19, 1999)

*Re: (secondgen)*

Here are some 'tips' you can call them secrets if you like







Generally I tune fuel with 30deg timing from about 3500 up then worry about the timing. Get the 100kpa fuel flat, then at the dyno you can use the multiply feature to move the entire range up and down to find where it makes peak power. Generally there won't be a big difference in the 12.5-13.5:1 range on an n/a car anyway. The power loss up top just looks like a loss of actual ve, not over fueling. 
Spark on a dyno is easy, once you get the afr flat, and where it's making the most power start putting a deg or two of timing in it until it stops making more power or it starts pinging. Generally I end up between 32-35deg on most 2v motors on pump gas as long as it's 10-10.5:1 and has good squish (metal gaskets).
I agree with the tps settings, 1v/s is about the lowest I'd put a bin and you won't need much fuel there, maybe .3-.5ms tops. Most of what I do is rpm based accel so I forget much of what I've learned doing tps dot. I know rpm based works awesome on ITB's and might be similar with large single tb's as well. You will go nuts rich on tip in, but it won't buck like tps based might.
Hope that helps.


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## need_a_VR6 (May 19, 1999)

*Re: (Shawn B)*


_Quote, originally posted by *Shawn B* »_
http://www.vintagewatercooleds...928.0
Timbo's posted his there about a third the way down the page.

Also, I don't like that spark map it's VERY aggressive just under wot and it's not the stock spark map for any VW that I've ever seen.


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## AlbertoB1 (Dec 29, 2007)

Hey Wraith can you send me the spark map you're talking about? 
Thanks
[email protected] or [email protected]


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## AlbertoB1 (Dec 29, 2007)

*Re: (AlbertoB1)*

I am using MSnS version 029y4


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## secondgen (Jan 9, 2004)

*Re: (AlbertoB1)*

Been playing with the tuning, touchy AE's much better, still needs tweaking, the values are all really low, seems i don't need a whole lot of AE. 
I kept at tuning the VE table some, in area's you'd not normally see, and now, instead of snapping lean when you let off the gas, like i want it (like when engine braking) it snaps very breifly and quickly to ~12:1 and _then_ goes lean. All i can think of is that it's caused by the tau puddle being used up...problem is, i don't know how to remedy this.
Any one have ideas? I can upload specs if it would help.
Paul, i kept trying to send you msq's and the datalogs, but my email's having trouble sending such large files apparently.


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## need_a_VR6 (May 19, 1999)

*Re: (secondgen)*

Sounds like there's a delay before you're hitting decel fuel cut. There is a delay value for it, change it to something very small and see if that makes a difference.
Best bet for msq/log posting is to post a thread on msruns and attach it all. It'll help everyone else out to have it up there along with the problems/fix http://****************.com/smile/emthup.gif


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