MS3X sync loss problems

[jwasbury]

Glad to hear its running Bill, and you at least got to experience the "holy throttle response, batman!" feeling on the test run around your 'hood.

This whole thing has been an interesting technical read. I didn't realize that ITB setups don't work well with MAP only load sensing. My 911 race car has an ITB/EFI set up, but I "cheated" and bought it complete, running, and dyno tuned by Rothsport in Oregon. The EFI uses TPS only, there is a MAP sensor but it's not plumbed to the manifold, it only is sensing atmospheric for compensation purposes. Runs like a scalded cat...

Rothsport also makes this cute little brake booster manifold for EFI throttles. I don't know if it could help the brake pedal in your car. It's installed on my car, and I don't notice any lack of vacuum assist. With your skills I bet you could fab up something similar if you didn't want to spend the $, or wait for it to circle the planet to be delivered.
Welcome to Rothsport Racing - Engine Products

[cmonref]

Your cranking fuel curve looks funny -- much too steep. Here's mine for a 3.0L with MS3X. Note temp in F.



If anything, it looks like you have too MUCH fuel at today's cranking temp.

Brian

[billjam]

Yes, the throttle response is simply amazing, especially compared to a 930. I knew it would be good, but I was still pleasantly surprised by it.
As far as the brake booster vacuum supply is concerned, that little Rothsport doo-dah looks pretty neat, but as you rightly suspected, I'm already well on the way to fabricating my own version.
Nice toy you have there.

[K Sykes]

billjam - Your cranking PW looks awfully rich. I max out at about 300% and it fires up well.

This might also explain why you were able to push start, but not start with the starter. (no cranking enrichment). What does your ASE curve look like? and warm-up enrichment?

[billjam]

Originally Posted by cmonref

Your cranking fuel curve looks funny -- much too steep. Here's mine for a 3.0L with MS3X. Note temp in F.

If anything, it looks like you have too MUCH fuel at today's cranking temp.

Brian

That's what I was thinking as well, but only because it looks high compared to other curves. I also didn't want to keep increasing it in case the problem lies elsewhere.

Because the engine was firing on at least cyl #3 (where the temp sensor is located), it got up to 40*C while I was cranking. It just felt like it needed more fuel to start, so to keep the fuel into it, I pulled the curve up high past 40*C. I am sure it will end up more "normal" once I get it sorted.
I did try dropping the curve down low at one stage, but the firing seemed to die down, so I cranked it up again.

[billjam]

Originally Posted by K Sykes

billjam - Your cranking PW looks awfully rich. I max out at about 300% and it fires up well.

This might also explain why you were able to push start, but not start with the starter. (no cranking enrichment). What does your ASE curve look like? and warm-up enrichment?

Kinsley, I will try a more "normal" cranking PW curve at my next session.
Other curves below for reference.
I don't know the significance of it, but I did notice the WUE indicator at the bottom of the TS dashboard was flashing red and green when I was trying to start last weekend.

[Lapkritis]

Have you calibrated your TPS?

I see crazy values in your first msq... 967 low and 1008 high. Something not quite right there. To check, open a TPS gauge on the megasquirt dashboard and observe 0 to 100% throttle position. Pedal to the floor it should be 100% and then vary proportionally to the pedal travel with 0% with your foot off the throttle.

[billjam]

Originally Posted by Lapkritis

Have you calibrated your TPS?

I see crazy values in your first msq... 967 low and 1008 high. Something not quite right there. To check, open a TPS gauge on the megasquirt dashboard and observe 0 to 100% throttle position. Pedal to the floor it should be 100% and then vary proportionally to the pedal travel with 0% with your foot off the throttle.

What values would you expect to see for TPS high and low?
I have calibrated it several times because the low end reading seems to be inconsistent. It is very sensitive at low openings and can display anything between +/-3% when closed even though it is closing cleanly against the stops.

TPS seems to be very sensitive low in the range. Just touching the throttle has the TPS gauge flicking up to 10-20%.
The sensor is standard for these TBs (Triumph Daytona 675, Keihin brand).

[Tippy]

Yeah, those values are off for closed throttle for the TPS. 10-20% fluctuation during minor throttle movements isn't right either.

Wonder if the TPS acting up is causing the noise too during starting?

[billjam]

I have an unused TPS sensor on the RH TBs, so I may switch my wiring to that side to see if I get the same issues. Maybe the sensor has a problem.

Getting out of my depth here, but would an additional resistor in the sensor circuit help widen the gap between high and low readings?

[Tippy]

I'd use a multimeter on the TPS and see how it responds (one hooked up now).

I'd think a 9V battery would be ok for a short test.

[Lapkritis]

If you have the reference and signal mixed up it will return funky values. I would double check the pin out. Most are 5v reference.

[billjam]

Followed up on a few issues today with some degree of success. Thanks for the tips.

High and low TPS readings on multimeter were significantly different so it seemed to be working OK.
I swapped the pins around on the connector and recalibrated it. Closed and full throttle numbers are now 204 and 785 and its extreme sensitivity has disappeared.

Replumbed all the vacuum.
Now, the brake booster is fed from a small tank that is connected by six 6mm hoses to the old injector ports. Brakes are heaps better, but still not as light as they used to be.
FPR and MAP sensor are now hooked up to small vacuum ports on all six TBs instead of just one TB on each side. This is giving a much smoother reading on the MAP and vacuum gauges in TS.

Switched engine control algorithm to ITB.
Starts and drives OK but obviously still needs tuning as it is seriously rich.

I had a quick play with Analyze Live. Blipping the throttle while it was idling with Auto Tune running smoothed out the idle very nicely. This is seriously cool and I can't wait to try it out on the road. Might need to read up on it a bit first though.

[jpnovak]

Build thread on your vacuum canister is a must.

Glad you are sorting the problems.

btw, before you mess with cranking pulse widths and cold start algorithms you need to make sure your VE table is reasonably tuned. By this, I mean the car must idle, run and drive. The cold start is an additive amount of fuel on top of the VE table.

VE analyze live (VEAL) works great but is only as good as your target input values. Find the AFR target table. You can start with all values set to 13.5. This is a nice safe value where the car will run very well. Once you are driving comfortably, then start to lean and rich certain sections. For example, I run 13.1 at high load (up to and including WOT) to an rpm of peak torque and then transition to 12.8 going to redline. Use your cam choice to determine where peak torque is. The cruise bins are where the rpm and load values are for your engine when runnning flat ground at low throttle inputs. Use 5th gear as a reference. Run these as lean as you can before it hiccups or sputters. Tip. Increase timing as you are leaning the mixture. This will help tremendously.

Glad most of these minor issues are almost behind you.

[Tippy]

My biggest hurdles were the idle and take off areas of the map when I had large injectors that didn't like small PW's. Light loads, WOT, and boost areas, I used VEAL a lot, only "paintbrushing" in areas with number changes after driving and looking at AFR's. Meaning, if I saw it run rich all over a wide RPM and load range, I'd highlight all those cells and multiply by something like 0.8 or 0.9. Then I'd drive and see. Once closer, I'd run VEAL again until smooth.

I know you're are not running boost, but I can tell you, VEAL NAILS IT (AFR's) the first or second time!

One thing I learned from jpnovak is you have to have a smooth VE map without peaks and troughs in the 3D map or it'll have swings in the running of the engine making it jerky. That's where I learned VEAL cannot tune your entire map for you, it takes a blend of manual tuning and VEAL tuning.

[Tippy]

Oh yeah, I spent nearly 2 years struggling with cold starts. There are LOTS of variables (ASE %, ASE taper, priming PW, cranking PW, etc.). As jpnovak stated, you must have your VE map tuned or all the adjustments in startup and cold idling will be off since they MULTIPLY from the base VE number.

As you had, I had sync loss the first 5 seconds after light off followed by the ECU thinking it revved to 45,000 to 48,000 RPM. The injectors would go full open for this period and flood the engine.

One turn of R52 or R56 cured this.

I also had sync loss stopping at nearly every stoplight when the engine revved down to sub-1k idle. The above fixed that too.

Sealing the deal has been the new high-Z Siemens Deka's 80lb's that are more stable than the previous gen low-Z Deka 55lb-er's.

Everything became easier to tune. Not sure if MS doesn't like low imp injectors as much as high imp or the newer pintle and coil designs of the Deka's improved that much?

[Lapkritis]

The deka are that good.

[billjam]

If you guys have any suggestions on how to setup TS with two O2 sensors, I'm all ears! I have one in each exhaust bank.
Apart from the fact that I can't get both sensors and Innovate LC-1's working properly, I'm not sure I have them set up correctly in TS either.



I have set the main control algorithm to ITB at Engine & Sequential Settings screen. Should I also set to "ITB" at other locations for ignition and fuel? I notice that in the screen below, it has set itself to ITB for fuel load, but ignition load is still Alpha-N.

[billjam]

Back on this again today.
Just found out why my Innovate AFR gauge wasn't working ... I forgot to install the fuse!
My LH side LC-1 doesn't seem to be working, so I need to try and reload its firmware. Probably takes about a minute to do after spending an hour figuring out how.

In the AFR/EGO Control screen, I have now mapped all the injectors to EGO1, which is my good sensor.
What I am not sure about is whether this actually does anything if Algorithm is set to "No Correction".

Still getting my head around how VEAL works. Am I right in assuming that VEAL needs the EGO signal to make its corrections?

[Tippy]

Oh yeah, without EGO, no worky.