Even More Data 3.46

[TheMonkey]

Thought I would open up a thread to document the Sequencer install back into my Pontiac.

Sequencer has been in this car, but in a 'proof-of-concept' wiring (non-driveable, reverseable, just see if it works). It worked and sequenced, but I had very weird behavior with the ignition including backfires trying to get it started. Sometimes it would idle okay, but then got to a point where it just wouldn't start and ignition was not right. Backfires blew the intake gasket and started dribbling coolant on valley pan

So I punted any progress that I had in my Pontiac and put it in an '80 BMW which I was able to do fuel first, then ignition. See post 'More Data'. The same ignition problems surfaced, but with a lot of trouble shooting, found the problem while running existing ignition in parallel. Sort of back door fixed the problem by finding a configuration that did not cause the problem, and unfortunately Al was not able to recreate the issue. But I have put 5 thousand trouble free miles on that car and the tune has been light years better than the stock setup. Original ignition and other equipment is not even in that car anymore.

Al re-flashed the other unit I had with new code 3.46. I have configured it, and bench tested a lot to see if any of the old problems are still there. It looks good on the bench, so I think I have a configuration to plug in the car. I have worked long days wiring in a permanent, proper and clean wiring job to get the 2 ampseal connectors installed. Few more connections, and I'll report back with hopefully good news.

I start a new job tomorrow so I'll get things done as I can, but most will probably be on the weekends. Part of all the progress on the BMW can be attributed to the fact that I haven't worked in an office for a year and half.

Al- can you take a look at this MSQ and see if there are any oddballs that stick out?

Pontiac 455 > 030 NA
36-1 VR crank wheel, single VR tooth on unused distributor stub
10.25cr 230/236 HR cam 13" idle vac, 550 ft/lb at 4400 through cast exhaust
Edelbrock 4bbl throttle body with stock IAC valve and TPS sensor on traditional manifold
MPFI with 42# hi-z injectors
LS2 Truck coils
Innovate WB o2 sensor
Dual GM 1 bar MAP sensors
TanksInc mod to stock gas tank - in tank Walbro 255lph

[grippo]

Scott,

I checked out the msq and it looks ok and ran fine for me on the bench with a 36-1 wheel simulation.

[TheMonkey]

car fires up and idles great in wasted. as soon as cam sync gets plugged in, car dies (it took me awhile to figure out to unplug the cam sync to stay fired up)

i'll trouble shoot a bit to see what happens. maybe my cam sync is off by 180* on the cam rotation, but i used the exact same settings from previous sequencer on earlier firmware.

the VERY good news is that the ignition signals look super solid.

[TheMonkey]

as you can see in the datalog, car just dies right away when cam sync is plugged in.

i was thinking that maybe the cam signal was programmed 180 degrees off, so i changed my 'spark fuel offset' from '2' to '6'. this is on a V8 motor, so in wasted mode, shouldn't it run just fine with either setting (as long as it works in one of them).

even without plugging in cam signal wire, car would not start when trying that change.

anyhow, any suggestions on why it won't swap to sequential?

[TheMonkey]

After a bit more reading, I see I was prob pulling on the wrong lever. Offset is fuel cyl relative to ignition cyl.

I could physically flip the cam sensor by 180, but is there a way to do it in the programming?

[TheMonkey]

i gave the cam sync sensor a 180 fliparooski, and it fired right up and sequenced. the firmware definitely changed on this. see my bench testing comments from Jan-09 on previous firmware (holy cow - it's been that long?), now it's flipped:

Jan-09:
"i did not know if the sequencer would set my #1 TDC at 70° after cam sync, or 430° after cam sync. turns out that with cylinder offset set to 0, after wasted spark, and the cam syncs.... computer sets my number one cylinder at 430° after cam sync (or 290° before cam sync) - for some reason i would have thought it would be on the other cycle. but, it's consistent, so that's what is important."

http://www.microsquirt.com/viewtopic.php?f=90&t=23163

or... perhaps what has changed is that now i am programming a negative offset - that changed from previous. ***edited to add: i just tried it with old positive offset setting (all original settings), and it fired up okay... so it's definitely the firmware that changed***

also, i remember from my previous install, i set spark-fuel-offset to 2, and trimmed the fuel to hit the spray right where i wanted it in the cycle.

[TheMonkey]

also- i can't figure out why my Gair is at 92. my intake air adjustments are set to 0% correction accross all temps.

[Matt Cramer]

The 0% correction is on top of the standard correction curve, which is based on the ideal gas law.

[Bernard Fife]

TheMonkey,

92% is a reasonable number IF your intake air temp is over 70*F. Since your intake air temp is likely higher than 70*F, it has expanded and is less dense, maybe to about 92%.

There is more on this here: http://www.megamanual.com/v22manual/mfuel.htm#law

Lance.

[TheMonkey]

Thanks guys. I did some fooling around with the air density you pointed me to, and I didn't realize what a big adjustment was made before the user programmed curve.

Time to move on to tuning....