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Random Accel Enrichment Triggering
Posted: Mon May 04, 2009 6:33 pm
by brownms
It seems that my acceleration enrichment triggers almost randomly. I can be cruising along at 2500 rpm, constant throttle, constant MAP and the acceleration enrichment will trigger causing the engine to stutter. Can't tune and engine like that!
It is at its worst at 2500 rpm, but will trigger at other rpms, to a lesser degree, both above and below 2500 rpm.
At this point I have operated the car on 100% MAP-based accel enrich and also 100% TPS-based accel enrich, but no change with either.
Could this be electrical interference?
Should I try to test the car with no accel enrich (both MAP & TPS at 0%)?
Attached is a .jpg of a MegaLogView file showing steady state operation, with the accel enrich triggering.
Engine Config: MS II, V3.0; code: 2.873; 3.3L turbo; KnockMS
Help!
Regards
Mike
Re: Random Accel Enrichment Triggering
Posted: Tue May 05, 2009 4:04 am
by grippo
This sounds like the same problem in the Mapdot Question post in this same subforum. I don't think it is electrical noise because it would seem that it would show up in the MAP graph. So try the mapdot scale factor change in your ini or try upgrading to the latest code rev and ini.
Re: Random Accel Enrichment Triggering
Posted: Mon May 11, 2009 6:38 pm
by brownms
G'day Grippo...
I changed to the latest code as you suggested: v2.89. And I'm using MegaTune 2.25 p3 from DIYAutoTune.
I'm still getting the same random acceleration enrichment.
See the attached MegaLogView .jpg for an example. Also note how spiky the coolant temperature is. I think I will check all my wiring...just to make sure.
The .jpg is showing some spikes in the MAP, which are translated into acceleration enrichment
Do you have any more suggestions? I'm stumped!
Regards
Mike
Re: Random Accel Enrichment Triggering
Posted: Tue May 12, 2009 6:34 am
by Matt Cramer
You might want to try installing a fuel filter and a restrictor orifice inline with the MAP sensor and see if that smooths things out.
Re: Random Accel Enrichment Triggering
Posted: Tue May 12, 2009 8:39 am
by brownms
G'day Matt...
With regards to the Fuel Filter and Orifice, is the order:
Engine, Fuel Filter, Orifice & MAP Sensor
Or
Engine, Orifice, Fuel Filter & MAP Sensor
Regards
Mike
Re: Random Accel Enrichment Triggering
Posted: Wed May 13, 2009 5:00 am
by Matt Cramer
brownms wrote:Engine, Fuel Filter, Orifice & MAP Sensor
is generally the preferred order.
Re: Random Accel Enrichment Triggering
Posted: Wed May 13, 2009 12:59 pm
by brownms
G'day Matt...
Forgot to ask yesterday:
Any particular volume for the Fuel Filter?
Any particular size for the Orifice?
Regards
Mike
Re: Random Accel Enrichment Triggering
Posted: Wed May 20, 2009 8:17 am
by brownms
Hello...
I added a 'fuel filter' to the MAP line which smoothed out the MAP signal, did not add the orifice. The trace I get from datalogging is smooth.
But, after the last run in my car I was getting no acceleration enrichment at all! The opposite problem to previous! See .jpg for logged data. Also, my AFR got very spikey (see 2nd .jpg) and then eventually smoothed out back to normal. This getting a little crazy!.
Also attached is my .msq file. I'm thinking I have screwed up a number somewhere.
I have no idea where to go now. Any hints?
Regards
Mike