T3 megasquirt II conversion

[Devastator]

Overall, things are working well. But I'm trying to think of some way to make that adjustment more automatic.

Make tuning your VE table automatic or a free air calibration automatic?

[Piledriver]

Well, I'm in Portland OR today with the square. As I came down in altitude yesterday, it got pretty lean and today we did a free-air calibration and let autotune adjust the VE table.

Overall, things are working well. But I'm trying to think of some way to make that adjustment more automatic.

Max

It should BE automatic, but you have to shut off the engine for a moment unless you have a second baro installed.

If you do a lot of altitude-changing driving, you should consider adding second baro as std MS uses a reference taken at turn on.
If you have a reset at light cruise, it will probably run badly, as it will grab another reference when it restarts, while underway, at part throttle and 50KPA ... You CAN set limits in MS2-extra, but it's a pretty easy mod.

[Max Welton]

I just got back from a 7-day road trip to Portland Oregon, Phoenix and back home to Colorado.

While on the highway, my VE table worked pretty well. Smooth and well-behaved during gas and food stops as well. During most of the 860 mile PH to Colorado Springs leg it averaged 29 MPG cruising at 65 mph.

But I'm still having some trouble getting consistent results when the heads are not at highway cruising temps.

I have some type-3 heads to have rebuilt. I have the stock CHT sender to use with the left head. What is that sensor electrically? I'm looking for a way to use it with the MS ECU to control the warm-up enrichment.

Max

[akokarski]

Hi Max,

Three posts down there are graphs for temp sensors.

http://www.thesamba.com/vw/forum/viewto ... start=2980

Anton

[Max Welton]

BahUtifull!!

Thanks Anton!

Max

[Piledriver]

I think that sensor is supported, one of the preset selections in Ms2-extra 3.0
(Temp sensor 2 in the head)

Remember, if you just leave WUE "ON" you have tweakable AFR and timing curves with temp over the whole range... It's too bad AFR target tweaks aren't supported at the moment.

[Max Welton]

Figured out why my VE table would work great in the morning and suck in the afternoon. Miss-calibrated IAT sensor. I was using the data from the DIY page.

http://www.diyautotune.com/catalog/gm-c ... p-115.html

When I measured 115ºF with an IR gun and the ECU was showing 90º, I decided to try the default GM settings from TS.

Bingo.

Now I can try the type-3 distributor. But I need to flip the drive-dog around, picking up the appropriate punch tomorrow.

Max

[akokarski]

Nice!

For drive dog pin, finishing nail setter will work in a pinch...

http://milo.com/dasco-pro-nail-set-kit

Anton

[Max Welton]

I'm stumped. Several times in the past few weeks, my system has come up 1-2 points rich. I thought I had whipped it by recalibrating the MAT sensor. Today it happened again. I was able to correct it by shutting and restarting. But this time I caught the "before" and "after" in a log. I'm hoping someone can spot something in the data I am missing.

The log begins with it misbehaving. At about time 55 I shut it down and restarted. You can see a small jump in the time.

Leading up to about time 55 (when I shut it off) is a section at idle. AFR is fat and PW is over 7. RPMs at this point were low (~600s) and rough.

After the restart, the car again ran smooth and normal. At around time 261 is another idle section with similar map, clt and iat as leading up to time 55. But AFR and PW are right where they normally are.

Anyway, I'm stumped. The zip file contains the log and my current tune file.

http://www.maxwelton2k.net/tech/2011-03-29_17.40.17.zip

Max

[Piledriver]

Put up your reset counter as a a gauge...

Since I pulled my motor a couple weeks ago to fix a leaky gallery plug, I occasionally see a reset during warm up (still working on that) but in my case, it's just annoying, no issue as I have second baro... The battery ground cable now goes to the transmission, not body, helped some.

Without 2nd baro, the MS will grab the current MAP as a reference.
The setting does have a limiting range entry.

[Max Welton]

According to this particular log, Gbaro was 110 at the beginning and 100 after the restart. Initial start was at 6000' and probably 5-600 feet higher at the restart.

Does Gbaro represent that initial sample at start-up? Do the 110-100 numbers sound right for the change in altitude?

Max

[Max Welton]

Not seeing anything in MLV that looks like a reset counter... ?

Max

[Piledriver]

Not seeing anything in MLV that looks like a reset counter... ?

Max

It would be a gauge in TS, resets when you power cycle.
reset counter and reset reason are different... no idea what the latter is.

Don't know if it's in the logs.

[Max Welton]

Thursday, another recurrence of an apparent bad baro sample leaded to poor running. I dragged out the laptop and saw that it was reading 80.2 instead of the usual value of 100. I restarted the engine several times there in the parking lot and it did not change.

So I limped it about a mile down the road, pulled over and cycled it again. This time it came up good and ran normally.

I'm starting to think there may be problem with the on-board MAP sensor. Thoughts?

Max

[supaninja]

add another baro sensor and have continous baro correction but if that baro sensor is jacked up then it will mess up you tune since the IM pressure readings would be off.