FI Build-up - German Plenum/TB & MS-1

[Chip Birks]

Are your wideband and MS grounded to the exact same spot in your car?

[Vee Dub Nut]

Can you look at a log from the wideband, and an identical log from Megatune? Reason I ask is it may in fact be reading correctly, but the 'lag time' of MT might be causing you to read false readings. In other words if you see 14.7 AFR on the wideband readout, then see the same thing in your logs a second or so later...

Not with out another serial adapter unfortunately.

[Vee Dub Nut]

Are your wideband and MS grounded to the exact same spot in your car?

Yes it is.. I have a terminal strip just for grounds that all the wideband and MS stuff goes into, and its tied into the chassis ground where the engine and battery ground.

[ToRy 70]

How old is your LC-1? Depending on the serial number, you may need to add a resistor to the MS input.

http://www.diyautotune.com/faq/faq.htm#LC1wiring

[Vee Dub Nut]

How old is your LC-1? Depending on the serial number, you may need to add a resistor to the MS input.

http://www.diyautotune.com/faq/faq.htm#LC1wiring

Its new.. Mine does not fall into that category.

[Vee Dub Nut]

Wondering if some of you experienced MS'ers can lend me a set of eyes and look at my data log from a cold start. The cranking PW seems to work well for my car, and the enrichments seem to work nicely as well. The only thing I'm having trouble with is the afterstart.

Generally, the first try the car starts up on the cranking PW and then immediately dies out. On the second or third try (depending on how cold it really is) the car will start on the cranking PW and then the engine speed slows WAY down and it almost dies but then it will catch itself and settle out in a great idle. From my data logs, I cant seem to tell that the afterstart is actually doing anything to my PW. Its set on the cycle ASE timer for a total of 250 cycles with a normal decay. Is there somewhere else that I need to turn ASE on? What seems to be catching the engine and helping to keep running is when it almost dies and the MAP goes back up near 100kpa and the ecm throws more fuel in the mix. I thought about just telling it to use a fixed MAP of 100kpa for the "fixed time period" then go to my real map and decay out the enrichment, but that seems like a bandaid fix. I should be able to use the standard decay.

Any way to upload a .msq and log on the site?

[MarioVelotta]

I made you a spot in my gallery to host your files. Check your mail.

Before you get to far this is how I try to deal with cold starts,

I hook my lm-1 to constant power before I do a cold start test, Let it preheat. It usually takes about 30 seconds. I start the logging software and then give her a go. I will cycle the key untill it starts on its own. Once it starts I will let it for run for another 30 seconds or so then shut it off. Then I will stop my log. Go back inside and take a look.

It works pretty well for me that way. Look your log over and see what it tells you. Rich on startup, lean on startup etc..

As far as the afterstart goes, I think you can pull that out in a datalog to see what it's doing

[Vee Dub Nut]

Thanks Mario... I just uploaded my current MSQ and a cold start data log.

My cold start procedure is not too far off from what you have said. My biggest issue is that I can't see that my ASE is actually doing anything. What I did is hooked up the computer and started the log. Turn on the key, let the LC-1 warmup, then try to start. If it stalls, key off and back on, let LC-1 warmup again, then try to restart. Once running I kill off the log after a while.

Thoughts?

My files are uploaded here:
http://www.thedubshop.net/gallery/index.php?cat=10003

[MarioVelotta]

One thing is the crank advance is only 8 degrees I would put that at 10-12 to help with starting. In your advance table you can also change the first row RPM to something lower than idle say 500 and the next to 750. Chance the first bin numbers up a couple degrees to help catch the rpms if they start falling.

I know this do anything for the ASE. So just to see what it is doing change it to fixed for say 5 seconds and fixed map of 60 then check your log to see if it shows that fixed PW for 5 seconds.

You could even play with the "idle advance settings" to get a fixed idle advance to help smooth thing s out even more.

Do a couple more logs tomorrow and post them up. Do you have any logs you can post up once it is to temp and running normal?

[Vee Dub Nut]

I'll give that a shot. That was what I was thinking my next move would be.

It will probably be late this weekend before I get to try it, got a lot of company up this weekend. I'll post up the results.

[miniman82]

I've been toying with my cold settings too. One thing I noticed was that my engine does not need as much fuel as you might think when cold, it will actually flood pretty easily. Before I messed with it a few days ago, it would just sputter and run on 2 cyls till it got warm. Then I got sick of it all and pulled out literally 1/2 the fuel at warm up, lo and behold it started without sputtering and ran smooth! I've finally come to the realization that because FI is so accurate, and because the fuel doesn't have time to evaporate like it does with a carb and long intake, you don't need so much gas when the engine is cold.

One thing I wish MS had is the mixture knob SDS has, so you could play with it and figure out if you needed more or less gas instantly.

[MarioVelotta]

I found the same Mini, when I made the change over to my MS2 with added cold start and idle features it seemed way over fueled at startup. I too got fed up and set EVERYTHING to 100% and added from there instead of starting rich and going leaner. When I was MS1 extra I had it dialed really well and it was about a key bump to start.

It seems to me that if you start rich it takes awhile to burn off that extra fuel and it will run like crap. If you start with less it just won't start.

[raygreenwood]

I've been toying with my cold settings too. One thing I noticed was that my engine does not need as much fuel as you might think when cold, it will actually flood pretty easily. Before I messed with it a few days ago, it would just sputter and run on 2 cyls till it got warm. Then I got sick of it all and pulled out literally 1/2 the fuel at warm up, lo and behold it started without sputtering and ran smooth! I've finally come to the realization that because FI is so accurate, and because the fuel doesn't have time to evaporate like it does with a carb and long intake, you don't need so much gas when the engine is cold.

One thing I wish MS had is the mixture knob SDS has, so you could play with it and figure out if you needed more or less gas instantly.

Yes, even stock injection systems have this very same problem. If memory serves Bosch mad at least two different thermo time switches for the cold start injector. The normal one that kicked in a little below 50F was always too much. Many times unless it was at least in the mid 20's outside....I simply disconnected the CS injector plug.
To further that problem....on well tuned engines....I usually disconnected the ambient air temp sensor in the winter because it simply added about 10% across the board for enrichment....and was usually too much in cold weather.

Mixture knob tuning thoughts...were the same reason I eventually plugged a variable resistor ballast into my CHT. In the winter when its really cold....and was down into the range where the CS injector would fire off, to have the CHT upclose to 3000 ohms was simply far too much fuel for winter starting. Yes this is all factory old injection....but the same issues. It makes me wonder where the thought process was that the engine really needed that much fuel for cold starting. Or....was it simply the relatively sloppy state of tune most factory engines came with? Ray

[Vee Dub Nut]

Just an update, but not so much really..

Haven't gotten a change to check my cold start stuff yet. It will likely be a couple of weeks until I get the chance. Work has been crazy, got a wedding to go to next weekend in Georgia, and the big Texas VW Classic the following weekend. The Classic will give me a good chance to log quite a few cold starts and try different settings.

I'll post my findings..

[Vee Dub Nut]

Ok.. been playing with the afterstart. Right now I have it holding at a fixed MAP of 100kPa for 5 seconds, then decay over the remainder of 20 (i think?) seconds to normal. The engine will now start on the first crank. Its not the smoothest over the first few seconds, but it seems to settle out quick. I'll try a few more things here and there to see if I can smooth it out some more.

The second update is that it is now confirmed that..... EVERYTHING FITS UNDER THE DECKLID.. WHOOP

Getting ready for the Texas VW Classic this weekend. Looks like there is some chances for rain over the weekend, so I finally got around to pulling my standoffs off the hood so I wouldn't get rain in the engine compartment. I had props on the top and bottom, and thought I'd only be able to finagle the top ones out thinking the air cleaner would hit the hood. Turns out I put everything back to stock and it all fits nice and snug. Total sleeper status with the stock wheels..