Cold Start Issues Still

[JasonS5555]

Look at this spreadsheet which is the same, but I added a SOIT cell that subtracts the injection time in degrees to the EOIT so you can easily see where it is.

EOIT Worksheet.xls

[JasonS5555]

So yes, then I would set SOIT to maybe 377 or something like that. So a little less than the 6.7. Keep in mind that this will vary with idle inj pulse width and will effect part throttle driving as well. 6.58 give SOIT at 377 with a 3 ms pulse width.

I haven't seen a big impact on the LTFT when I've been playing with the inj timing. I kind of expected to have to re-tune the VE tables. But so far I haven't.

[JakeFusion]

This may be the fix I was looking for. Thanks very much Jason. I couldn't figure out why the hell the car kept changing it's attitude when cold vs when warm (and it acted fine when warm).

What do you make of that spreadsheet? Edit: nevermind, saw you updated as I posted. I'll look at yours.

[JasonS5555]

Glad I could help. Others here have helped me tons. The spreadsheet helps me a ton. For bigger cams I think you have to ignore the "adjusted" numbers and look at the actual numbers. Then tune the SOIT and EOIT based on the actual cam events. But that spreadsheet is invaluable to help determine what table values will actually give you the injection timing you want.

Jason

[JakeFusion]

The EVC actual normal is the number to use right in the Normal Injection Target vs ECT table? 5.49 is what I get when I adjust my pulsewidth and adjust the cam timing slightly.

[JasonS5555]

What pulse width are you using?

[JasonS5555]

I'll tell you how I use that sheet. The one I posted that is.

Enter cam events
Enter my inj pw
Enter idle rpm
Play with boundary and normal until the SOIT is close to EVC 0.06.

I don't use any of the cells that compare my cam to a stock cam. IE the blue cells.

[JasonS5555]

See if this helps

EOIT Worksheet Jake.xls

[JakeFusion]

Okay so you have 6.29 in there too.

I don't know what to use on the IPW. I have the minimum injector pulsewidth.

Anyway, I played with the timing a bit. This seems to work well for my cam events (367.1 SOIT and 367 EVC and 3 IPW):

6.5 boundary
6.29 normal
6.48 makeup

I'll see how that does with the cold start and cold load issues.

[GHuggins]

Injector Pulse Width should be displayed in your datalogger. Use the min number seen durring hot idle. From your last datalog posted the min I caught was 2.6ms. Hope this helps.

[JakeFusion]

It does. Thanks!

[JasonS5555]

Hey Jake,

I don't know where the 6.29 number is coming from. Again, I don't use any of the numbers in blue. I'll post another sheet that removes all comparison to the stock cams which for a big cam are really irrelevant. ONLY the numbers that I'm entering in pink at the top, and comparing the resulting numbers in green, SOIT and EOIT to the actual cam events which are shown below for 0.050 lift.

EOIT Worksheet Jake 3.xls

Based on the above, I would use 6.5 and normal of 6.58.

Also keep in mind that you inj pulse widths will be a little wider when cold.

Thanks,
Jason

[JakeFusion]

Yeah, I was tired and sunburned last night. I'm about to go try the numbers to see.

[JakeFusion]

That didn't do anything. If anything it was actually harder to start. Here is the current tune. Several logs. First is just trying to start it. Next is me opening the throttle blade to .73V (which resulted in a 1500 RPM idle), then .67V hot idle with hot counts in the 20s for IAC vs the .69V with 50 hot counts IAC. I also have one where I turned the A/C on (just charged it up, so wanted to see what it did - bogged the motor but with no adaptive airflow it worked).

I'm beginning to think the throttle body may be the issue. I swapped to NW becasue the FAST has almost no bypass air with the IAC port whereas the NW is considerably larger. But I'm wondering if I don't need more bypass air in the IAC port. There's a balance that adjusting the blade perhaps can't hit. It idles fine in gear at .69V (but P/N idle is higher than commanded - leading me to believe there is more air bypassing the blade than needed). .67V idles closer to commanded for P/N but gear IAC counts go into the 20s to maintain the same idle. If the IAC port were larger then .67 or possibly less work work?

I had a FAST on there before and it idled at the same counts at .47V and seemed to allow more bypass air around the blade than the NW. The issue was the IAC port was smaller and didn't look as easy to "open up." But I think at this point, I may open them both up and see which one does better. I thought the cold start issues were related to the FAST's IAC but the NW didn't fix it. If anything, the FAST actually drove better...

Also, my lean idle seems to have enriched by delaying the EOIT. I'm seeing my O2s reading in the 80-90s vs 0-40 before... so do I need to lean it out a little more now that more fuel is actually making it into the combustion chamber?

Finally, I returned most of the airflow and fueling tables to something close to stock to adjust some of the variability out of it. I also enriched the Cranking F/A Multi tables by 5% to see if that would help... nope.

[GHuggins]

Something just dawned on me while watching your datalog. Your Air Fuel sensor isn't hooked up is it? Your commanding a 14.12 af ratio, your wideband shows 8.81 even though your O2's are hinting at it running somewhere around 16 to 17+... Can we get a correct air fuel reading? Your tune has the idle and cranking fueling cut over half original from other 350's VE tables I've seen. Would explain a whole lot. You've been going after the correct thing - fueling, but I believe due to the fact that your VE is so lean that your going to have to add a whole whole lot more to everything than what your doing. I'm assuming you leaned out the VE table for bucking or idle smell or something of this nature? The injection timing should have corrected that. Get your VE table correct via working af sensor or re-enable and use long term fuel trims. Then see how it runs. I bet your idling 17 or 18+ af ratio, which would explain everything...

[GHuggins]

Ohh, almost forgot. If it was indeed a lack of airflow issue all you would need to do to verify it is slightly depress throttle while cranking (very, very lightly crack the throttle) and see if it fires. If not - you know it's fuel, which everything so far is pointing to...

[JakeFusion]

I just didnt have my wideband hooked up for this. It's in my cfg file tho. I idle around 15.4:1 with the wideband (which is not super accurate with a cam with a lot of overlap) and close to 0mV with the narrowbands. I played with the VE table a lot to get it to where it is. Again, stable idle was the goal which I have when hot. Anywhere in the cold regions of the ECT and it's a big fat no. For example, the A/C kills the car if it's not at least at 165 ECT.

But if I crack the throttle when starting, it actually kills it. Like more air = even leaner. That's why I continue to think it's a fueling issue. Why it needs so much more fuel at idle vs other cars is baffling. Could I have a leak that doesn't show anywhere else?

Also, I've added a ton of fuel to the fueling tables. To the point where it lights off and dies from too much fuel. It's hard to make adjustments there because once you've fired the car at all, you've screwed with the A/F. But I've often thought the A/F during cranking was off. I just don't know where to look to really fix it.

[GHuggins]

Well, you just confirmed fueling problem... It is possible to have a vacuum leak. They do show more at idle than with throttle, but that's as simple as sealing and smoke testing your intake to check. Get your idle fueling back to 14.6 or so and see what happens. These older motors were more fueling sensitive. Almost is starting to sound like your Open Loop fueling is more of any issue since it only dies in open loop. How far off is your fueling commanded vs actual durring idle. Finally what method are you using to keep it lean at idle? PE or permanent OL?

Tell ya what, get your idle af back in the 14,s. Do a cold start with af displaying. Then come back with the results...

[JakeFusion]

Well, the way I have it setup is it's in closed loop from 1200 rpm up. Idle is in Open Loop due to the overlap. It idles absolutely fine at temp. In fact, if I could operate at 180 ECT only, I wouldn't have any issues at all. I do not want to enrich the idle in the VE tabe. I went through the hunting idle due to a rich condition and am not going back to it. I use the F/A Open Loop table to add fuel when cold (as you can see, I'm at 1.00 above 176 there and in the 1.06 range when cold in the 65-70kPa range). I show richer idle (see the attached log). You can watch it lean out as it warms up. It does not like being rich at idle at all. I've even thought of leaning out the F/A OL table some more.

The whole point is, at temp, the car works exactly as I want it to. During the warm up or cold start, it does not.

I appreciate the help. Just seems like I've done everything that can be done. Which leads me to believe it's not even an issue with the tune. Something mechanical. Or something off with the injector data. My VE table is in line with other large cams. The fueling requirements at startup are not.

[JasonS5555]

Hey Jake,

It sounds like you have more than one issue. The fueling sounds like you improved things with the inj timing change. But looking at the no start log, what doesn't make sense to me is that the dynamic air is around 1 lb/min, the desired is around 3 lb/min and yet it is decreasing the IAC counts until it kills the motor. I'm trying to figure out why on earth if it knows that it needs more idle air, why is it pullilng the IAC from ~300 down to ~ 220. That's clearly making things worse.

Thinking about that one....
Jason