Startup problems/issues

Keithg · Post by **Keithg** » Fri Nov 30, 2007 9:50 am

It is now officially cold. I am trying to get my startup sussed on my 4 cyl turbo with PWM idle solenoid. What I note: My idle solenoid is *wide* open during ASE yet my ASE values range from 5-20%. This is a result of the system trying to add more air to an overly rich mixture. The base code had these values above 100% (like it was in MS1/E) and that about drowned the engine. I still may be able to drop them more (probably can) but am having trouble getting from crank to run without a stall. Delicate balance, I know, but I had it before with MS1/E and am sure I can again. Does anyone have a MSQ of a recent beta that they are happy with crank and start. Preferably a 4 cyl, but I am interested in any suggestions. I forgot to grab a MSQ, but will do later.

KeithG

mattd860 · Post by **mattd860** » Fri Nov 30, 2007 10:07 am

This probably won't help but how is the timing from crank to run? If there is a big jump or drop in advance from cranking to running, it may effect starting. I recently tuned my very low rpms and high load bins on the timing table to be closer to cranking advance and starting is quicker and smoother now.

UnaClocker · Post by **UnaClocker** » Fri Nov 30, 2007 5:17 pm

Yeah, I've been fighting this problem for the past couple of weeks as well. Slowly increasing the ASE percentage, as well as the warmup #'s down low. So far I've doubled my numbers, with no results. Exactly the same as before. First start of the day, fires and dies within 1 second. Start back up, and it stays running. Every time, doesn't matter what the temp outside is really, first start after sitting 6 hours or more, and it does that. Makes me wish the MS had a constant power feed so it could keep some info in ram.. Like when it was last started, so it can decide to quadruple the fuel on the first start, or whatever it takes. It's not like the engine has any time to warm up in the 1 second it was running. I guess I'll be doing some datalogging this weekend to see if I can finally nail it down.

460stang · Post by **460stang** » Sat Dec 01, 2007 12:46 am

With a B18 honda engine I have crank values over 800% (not typo) and still could not get first cold start. I have up them to over 1000% and will see next cold start. But once it fires over cranking speed the ASE values are normal, it does not stall.

This does seem extreme, for cold start cranking. The engine starts fine when slightly warm.

UnaClocker · Post by **UnaClocker** » Sat Dec 01, 2007 8:57 am

460stang wrote:With a B18 honda engine I have crank values over 800% (not typo) and still could not get first cold start. I have up them to over 1000% and will see next cold start. But once it fires over cranking speed the ASE values are normal, it does not stall.

This does seem extreme, for cold start cranking. The engine starts fine when slightly warm.

You sure your injectors are big enough? I would assume you have pegged your injectors at that point.. That, or MS is ignoring the values?? Which is what I was beginning to suspect, since I have gotten no improvements yet.. Hence the reason I want to datalog a startup..

UnaClocker · Post by **UnaClocker** » Sat Dec 01, 2007 10:08 am

Strange.. I went out there, fired up the laptop, enabled datalogging. And proceeded to start the car like I would normally. Start, die, start, run.. And the bloody thing didn't log the first one.. I have Start, run.. Not the start, die.. I only ran the thing for 30 seconds or so... I'll wait a few hours and try again. It's wicked cold out today..

Maybe I'll leave the ignition on a second or two before cranking the first time, to ensure that I have an actual connection to the MS before I start cranking.

460stang · Post by **460stang** » Sat Dec 01, 2007 10:11 am

The injectors are stock honda 240cc for this engine.

My last setting at 500% cold start cranking was almost impossible to start, at 800% the next morning it took 3 tries and then it flashed up and ran fine on high idle etc.

I am not sure that 1000% will actually net me more fuel but I had to try it.

Just as a side note this is at about 0 deg C.

Post by **muythaibxr** » Sat Dec 01, 2007 2:24 pm

Have any of you guys having trouble with cold starts tried increasing your priming pulse? That would probably help significantly (always has in my installs when I have that problem)...

That and adding ASE, and increasing the cranking RPM (making the cranking pulse width continue longer than it would otherwise).

Ken

UnaClocker · Post by **UnaClocker** » Sat Dec 01, 2007 5:29 pm

I currently have zero priming pulse. If I remember right, the priming pulse does not change with temp, so it was just too much once the car warms up. Seemed like a better idea for TBI than port injection. But heck, I'm at a loss right now, I'll give that a shot.
And yes, I did try increasing my ASE.. It's now double what I started with, and still, identical starting vs. the original numbers. And I worked my way up slowly. I don't think the cranking speed will change anything. I wish I could get this in a datalog, it fires perfectly, shoots up over 1,000 rpm, and as sure as if I turned the key back off 1 or 2 seconds later. It doesn't sputter first, it doesn't drop down it rpm first, it's just OFF.. I have ASE time set to 10 seconds.. So that's not it.. I don't want to call it a bug, because it seems like everyone would be reporting it, but it seems like when it changes the number of squirts, it stops squirting or gets outta sync or something.. Cuz it is squirting both banks simultaneous every time while cranking, right? That's what makes MS2E start SOOO much faster than MS1E, imho. But after it fires, it switches to my settings.. 4 squirts alternating..

Post by **muythaibxr** » Sat Dec 01, 2007 6:11 pm

Could be that switching to the larger number of squirts changes the fuel pressure...

Increasing the cranking rpm would keep it squirting simultaneous and using the cranking pulse-width to a higher rpm, probably injecting a lot more fuel than it would otherwise, which may help the problem... If you have not tried it, I doubt trying would hurt anything.

Ken

460stang · Post by **460stang** » Sat Dec 01, 2007 8:17 pm

There is a priming pulse table and it is temp dependent. I to try to keep priming pulse as low as possible to keep from flooding the engine when the key is cycled for whatever reason (as does the OEM). I run 3 MS at -40deg and 1.1 MS at 190deg

Post by **muythaibxr** » Sun Dec 02, 2007 9:21 am

I run as high as 10ms priming pulse cold on some of the engines I tune. I've never had the start-stall-start again problem.

The 20v 4age used to start, then run a bit lean and slow down a bit, then speed up again... So I increased the priming pulse, slightly decreased the cranking pulse, and increased the cranking rpm, and the problem went away.

I think enabling EAE helped too, because when it fires up, I get a nice spike in pulse-width since EAE thinks there's not much fuel on the walls (which is probably the case).

Ken

UnaClocker · Post by **UnaClocker** » Mon Dec 03, 2007 5:15 pm

Priming pulse did the trick for me. I set 10ms at 20f, and steadily worked down to 0ms at 110f. Funny thing is, it doesn't seem to matter if I turn the key on, and wait for the fuel pump to fire up, or just go from off straight to cranking, it seems to fire and stay that way. Cool with me..

Tjabo · Post by **Tjabo** » Mon Dec 03, 2007 7:34 pm

I don't know if it even relates, but I'd been having this same problem (start-stall-start-rungreat) with MS1Extra, and after reading this thread I jacked my run speed up from 300 to 600. This morning wasn't quite as wicked-cold as a couple in the last week, but the car fired right up and stayed running with only a little struggling.

Maybe it's moot for me now, I got my MS2E Beta loaded and tuned well enough to drive to work tomorrow. It seems a LOT more user friendly for the ASE, WUE, Priming Pulses, and a lot of other stuff. I'm looking forward to it!

Thad

UnaClocker · Post by **UnaClocker** » Fri Dec 07, 2007 6:30 pm

I finally nailed it down. Like I said in my last post, the priming pulse got it to fire and stay running on the first start of the day. But once in awhile, usually when the outside temp was 40f, the engine would stall after about 7 seconds. Above or below 40f, it'd stumble real bad at the 7 second mark, drop to about 500rpm, and then catch again. Like was suggested, I could raise my cranking RPM to try and catch the engine.. I didn't want to have it stumbling at all if I could avoid it. I THOUGHT I had the ASE taper time set to 10 seconds.. That must have been back when I was running MS1.. MS2 doesn't seem to have that kind of option. Fine with me, I'm happy with the way MS2 does it. I simply increased the taper time by a large amount, more time for the cylinders to warm up before it goes to my WUE. Bingo! Fires up on the first try, and stays running. Flawless! I am sooo happy with this!
To recap, I spent about a month slowly increasing my ASE and WUE numbers. That definitely helped, but I still had an issue with it stalling before even having a chance to use the ASE. Priming pulse did the trick, maybe it stabilizes the fuel pressure before starting, maybe that extra fuel does it (doubt that, since it'd be messing with the cranking pulsewidth, imho). And that got it to fire up and stay running almost every time. The final trick was ASE taper time, I needed more time before moving from ASE enrichment to WUE. My WUE #'s seem much better now, because I can actually step on the gas when the engine is cold without it stalling (no accel enrichment yet, one beast at a time).
Thanks Ken & James, good code.