µSquirt ( microSquirt ) powered Vanagon ramblings

[luftvagon]

Probably because the load (Manifold Absolute Pressure) changed, the leaner I went.

[luftvagon]

I just posted this in the electrical forum, I am thinking I should've post it in the Fuel form:

Interestingly enough, the stock location for Temperature Sensor II may not be the most ideal location for any temperature sensor.

Yesterday, after an hour of driving around, my recorded TSII temperature was 90F, driving around. The ambient temperature was 40F. When pulled over, idling at light, or parking lot, the temperature would go to ~110F. As soon as I start driving, it would drop top 90F, dipping all the way to 86F.... Rewind back to summer months, and my TSII recorded temperature was 120F or around 140F idling.

Granted, my sensor is much more responsive than TSII, however, that does not mean much....

What does it mean for the rest of the stock L-Jetronic crowd?

You may be running richer in winter, and leaner in summer. Are you? How is your MPG in summer months versus cold months?

Anyway, I am very interested in this observation.

[luftvagon]

Man, I love this... Soon I will be switching to touch screen tablet that will dock nicely into the ash-tray...

Code: Select all

3rd Gear
2100 RPM
65% Manifold Pressure (Load)
27.4  BTDC Ignition Advance
81F - Manifold Intake Temperature
113F - CTS Temperature as registered by thermoresistor located on the TempSensor II location
13.10v - System Voltage
16.2 - AFR

Can't wait to import GPS Speed, head temperature, oil temp 1, oil temp 2... etc

Coming soon - dockable dashboard and tuner:

[luftvagon]

MPG UPDATE
82 mile round trip, back-road highway with a very steep - 2 mile - 800 ft "mountain" climb yielded 17.2 mpg.
Two passengers (technically three -- one is in the oven cooking); We started at a gas station, tank full, round trip, back to the same gas station/pump for a re-fill. This was no hypermiling run! Not overly excited... However, I also have roof racks to contend with.

The question is, is it worth squeezing more MPG out of it... It runs great!

Current Settings

AFR Targets:


Ignition Advance Table:

[luftvagon]

The new tablet -- vehicle dash and diagnostics is in..



time to look for a way to add additional sensors via canbus link to my ECU.

[Amskeptic]

The new tablet -- vehicle dash and diagnostics is in..



time to look for a way to add additional sensors via canbus link to my ECU.

There is no question of your focus on actual driving when you are underway . . .

(your fuel mileage looks pretty good, let us know if you get deterioration at colder ambient temperatures?)
ColinNastyRearEnderWitnessedToday

[luftvagon]

Colin, I think I can make it slightly better with "EGO Control" now that my fuel map is very close to the actual AFR targets. The "EGO Control" feature makes it so the targets are always met in steady cruise conditions. I also enabled fuel overrun, which shuts fuel down during closed throttle, high vacuum...

What do you think about the timing? Part of me feels like there could be more improvements made... but it runs so good, and accelerates very good.... It idles very good too.. The only thing that is not 100% is starting -- it struggles a bit.. but always starts.

[Amskeptic]

I also enabled fuel overrun, which shuts fuel down during closed throttle, high vacuum...

What do you think about the timing?

When does the fuel get turned back on?

Timing looks fine. . . for you performance types. Since I am all about making my VW last as long as possible, I sacrafice a little efficiency for happy bearings.
Colin

[luftvagon]

The fuel gets shut off if:
RPM above 1400 RPM, and kPa lower than 30, CTS greater than 90 F, TPS lower than 5% with 1.5s.

The fuel is returned if the following condition is met.
RPM less than 1200 RPM with 0 second delay.
...or otherwise you step on the pedal at any time..

Works good..

[Boxcar]

great thread,thanks

[Amskeptic]

great thread,thanks

It is a great thread . . . I want to drive that Vanagon the next time I am in Arkansas.
Colin

[luftvagon]

Colin,
I cant wait to have you drive it, and actually help me map some additional performance and economy improvements. I took a 65 mile drive last night, in the frigid cold, and it yielded close to 19 mpg. The first 35 miles was a very hilly back road, and 30 miles was interstate.
I was watching my AFR guage maintain 15.3 AFR during highway cruise, at 80% load (3700 RPM / 3/5 throttle opening). This is the work of the "EGO Feature" - it will automatically seek to add or subtract fuel based on the current and desired AFR table:

[luftvagon]

Here is my current ignition map - which I recently re-did for better acceleration performance:



I basically took 009 distributor and copied it's 2-dimensional advance curve at 100% load (hammer down), and then gave it additional advancement as the load drops. I believe there are or is additional efficiency to be had with no load. This engine, once fully heated, under low load conditions (>89) can take some serious advancement.*

[Amskeptic]

This engine, once fully heated, under low load conditions (>89) can take some serious advancement.*

Remember somewhere in your intuition that you cannot feel over-advance effects on the bearings. The stress levels increase how do you say, quadratically? exponentially? and it is all smooth and quiet.
The first effect of over-advance that you can sense is a slight loss of power that is exactly the same effect as too retarded. It is, after all, the same bell-curve, just on different sides of it. Have you been able to come up with any cause-effect between timing and CHTs? Do you have EGT gauge? What the heck, might as well.

Nobody felt these unhappy bearings . . . :

[luftvagon]

Colin,

That's why I put that asterisk there (*). I have a VDO CHT gauge, but can't log that because I don't have an input for it - I'll get to that once I install canbus. I think I may have found the culprit why the stock TSII location is not working out for me. There may be a cold air leak that is cooling off the sensor. I can feel the cold air coming out from under the intake manifolds, jetting towards my temperature sensor coupler.