Accel Enrichment Duriation

Boris740 · Post by **Boris740** » Sat May 20, 2006 2:37 pm

I have been trying to unsuccessfully get the accel enrichments to work.
I am using RPM based accel with TPS based trigger. The problem is worst on hard acceleration from standstill. This is a turbo charged 740 Volvo with a manual transmission. What seems to happen is that the accel kicks in, I see the enrichment on the wideband AF dashboard gage, just as the RPM pick up it leans out. I am also somewhat confused by the units of duration used. In the RPM based accel the time is in ms with a limit of 25.5 (to short) In Accel Wizard the units are in seconds with a limit of 25.5 seconds which seems rather long. Which is right?

screamer69 · Post by **screamer69** » Sat May 20, 2006 5:00 pm

im going to be watching this one with interest as im haveing the same sort of problems !!

Keithg · Post by **Keithg** » Sat May 20, 2006 7:34 pm

Boris,

I am running a 16V turbo 2.0L (Saab). Take a look at my settings in my MSQ. I am running rpmAE, but use mapdot as my trigger instead. when I switched to mapdot and rpmAE, it was like someone switched on the 'smooth' mode. I recommend at least trying mapdot for your install. Note that I have my accel turned off in boost. rpms rise so fast in boost, that ae is not necessary, the VE table takes care of it. Make sure to look at 1) "Accle/Decel mode" 2) Acceleration wizard 3)rpmAE to get all the settings. I am not yet happy in warmup, but am getting there. fully warm, it seems to be fine with just a bit of lean tip in.

KeithG

[url]http://www.wideopenwest.com/~kgrider/sa ... squirt.msq[/url]

Boris740 · Post by **Boris740** » Sun May 21, 2006 7:40 am

Keith,

I used mapdot for a long time but had recurring random stalls. What would happen that occasionally at idle the engine would decide to slow down which would cause the MAP to drop. The idle control would try to stabilize which would further drop the MAP This would trigger the accel enrichment causing it to stall. I may go back to map dot trigger if someone codes this:
If RPM decreasing than kill AE. Not being a software person I do not know what it would take.

Keithg · Post by **Keithg** » Sun May 21, 2006 8:14 am

I dunno what to say, then. I have no stalls. I do find that mine likes to idle between 14.2-14.7 and can be a bit more prone to stumble at 15.0:1 at idle. One thing we did discover is that sometime during the 029 development, there was some change that affected ASE. It is now consistent, but requires much higher values to operate properly than with earlier codes. For example, I was previously at 30% ASE at 40F Now, I am at 130% and get more stable starts. If your stalling was during ASE, this may help. I am running 029q2.

HTH,

KeithG

Posted by email.

rs2000 · Post by **rs2000** » Sun May 21, 2006 9:13 am

Its probably not this, but make sure you have 'decay' selected.. Mine stumbled and wouldn't idle without it, apparantly it is a bug in some versions of the code that causes spikes that trigger the AE and cause the stumble/stall/hunt..

Boris740 · Post by **Boris740** » Sun May 21, 2006 10:11 am

I am running 029q. Didn't upgrade to 029q2 because I have to use Easytherm to compile. Was there anything else changed that would warrant the upgrade?

Keithg · Post by **Keithg** » Sun May 21, 2006 10:29 am

Not that I am aware of. Q was the same code as Q2, but with different inc files. I was running p and upgraded to Q2 this week.

KeithG

Posted by email.

KariM · Post by **KariM** » Sun May 21, 2006 11:27 am

Keithg wrote:One thing we did discover is that sometime during the 029 development, there was some change that affected ASE. It is now consistent, but requires much higher values to operate properly than with earlier codes.

Really? I've been reading this subforum daily, but I've failed to note that. I have not yet upgraded to 029 series.

Boris740 · Post by **Boris740** » Mon May 22, 2006 9:48 am

I am still uncertain of the units of measurement for accel. In the RPM based accel the time is in ms. In Accel Wizard the units are in seconds. In the accel /Decel mode the Accel timer is in seconds or cycles. When I am using RPM based accel it is not grayed out so I assume the selection is valid but what happens if I switch it over to cycles?

BTW I solved my lean out problem at hard accel from dead stop. It turned out that even slight unintended backing off the throttle would trigger the decel enrichment and it would lean out. I changed Cut Decel Setpoint (kPa) to 85 and now I can pull stumps again.

whittlebeast · Post by **whittlebeast** » Mon May 22, 2006 10:25 am

All of the duration times are in sec. They have been miss-labeled for a wile. I always seem to end up at about 60 kpa/sec and about .7 sec and decay AE.

Turn on the AE driven Fuel % gauge and play on a stim to see how all this works. There is a sticky above that may help.

AW

Boris740 · Post by **Boris740** » Mon May 22, 2006 11:26 am

whittlebeast wrote:All of the duration times are in sec. They have been miss-labeled for a wile. I always seem to end up at about 60 kpa/sec and about .7 sec and decay AE.

Turn on the AE driven Fuel % gauge and play on a stim to see how all this works. There is a sticky above that may help.

AW

So what happens if in Accel / Decel menu I switch the Accel Timer from seconds to cycles? When I am using RPM based AE trigger the timer is not grayed out so I assume the selection is valid but what happens if I switch it over to cycles? The Acceleration Wizard and RPM based Accel manus still show time units.

Megasquirt Support Forum (MSEXTRA)