aidandj

iTrader: (5)

You can get less pressure. If I go full throttle at a 20psi boost setting my 6758 makes 20psi of boost. 50% throttle makes like 10ish to the manifold?

dr_boone

iTrader: (1)

It is the skinny pedal that gets you in trouble (or not) not the boost control switch.
and my "pro tip": Run the wastegate pressure that you have and be happy with it until it is tuned perfectly. "Don't blow your **** up"

ridethecliche

iTrader: (2)

I've been having an issue that just started recently. The car cranks and doesn't start. It'll seem to catch, jump up in revs, then fall flat on its face. It has never done this before. After the 2nd or 3rd try starting it... no issues. Car runs absolutely fine when it gets going. Idles fine, drives fine, AFR's fine. The works. But... crank.... sputtterrrr sputtterrrr.... killll meeee slooowwww rpmmmmm droppppp.....dead.

Stefan had looked things over and said that it looks like it was a fueling issue at startup. Any input?

Tune and log attached. Sorry for the 'current tune' filename.(Fixed it)

I also have some issues with the alternator control where the car tries to die under load and the battery V drops like woah and the alternator duty cycle hits 100. I feel like I don't even have much on in those moments, but.... I'll have to sit in a parking lot and take a log of this once the car is warmed up.

Thanks for any input.

I'm actually quite happy with the wastegate setting right now. The car is a lot of fun and definitely gets out of its own way. I'd rather put on EBC so I can revert to the spring that lives at 7 psi instead of swapping springs already. My AFR's look solid so far. I'll take a few logs in the future and look at them for knock. I never felt the need to pull timing where I thought things were knocking since it was apparently way beyond threshold. If it keeps popping up, I'll pull a couple of degrees and see how things look after that. I'd just rather get EBC working longer term than swap springs. It just seems like the safer way to go since you can't go any lower than wastegate!

Given what my schedule is going to be like for the next few months, I'm not really planning on messing with anything that requires an uncertain amount of time to get right. My biggest upcoming project is getting the coolant reroute in. I dropped the car off to have the clutch done earlier today. I wanted to do it myself but that entire time thing... It's definitely going to hurt the parts budget for a bit. There's always ramen! So it goes.

aceswerling

I had the same kind of problems with the FlowForce injectors. I found that the engine would run but that fueling was inconsistent and I'd have weird idle problems until I (actually Curly) dialed in the dead times. Suspecting you had the same problem, I checked your tune and see that your settings are different than those on the Instructions ? Flow Force Injectors website.

1. I recall from earlier in the thread that you have an NB running 4 bar of fuel rail pressure. In your Required Fuel, you've got 630 cc, which is the 3 bar setting. The Flow Force website says
   Quote:

   " Flow rates are measured at 3 bar (43.5psi) of fuel pressure. If your vehicle has a different fuel pressure, make sure you adjust for this! For example, a 640cc injector at 4bar of fuel pressure will flow at 739cc."
   I believe others said earlier that this doesn't matter a ton, and I'm inclined to agree, but I'm also inclined to set it correctly for your setup.
2. Your dead time settings also look off. The base pulsewidth is correct at 1.261ms but I see 136% @ 13v and 84% @ 14v as opposed to the recommended 102.5% @ 13v and 90% @ 14v settings. You might try the settings from the Flow Force website at Instructions ? Flow Force Injectors and see if they help. There's also a screen shot for your reference.
3. Your non-linear small pulsewidth settings look correct. Good on ya for that!
4. I still had trouble after dialing in the injector settings because the voltage calibration was incorrect. Basically, that meant the Megasquirt thought the voltage was off by almost a volt. You might try checking that too. I've seen others on the forum suggest doing so by measuring voltage at the fuel injectors and then playing with the Max voltage number in the Calibrate Battery Voltage box until they agree. Honestly, I couldn't figure out how to insert voltmeter probes into those connectors but maybe you're smarter than me. I've been relying on a voltmeter built into my stereo, which has worked well enough. Or maybe just measure voltage at the battery to see if you're close.
5. When your car starts and then dies, does it die right away or does it kinda chug along and then die? If it's the former then you're Priming and Cranking Pulse settings are probably too lean. If it's the latter then they're likely too rich. You'll need to fiddle with those settings to get them to what the engine wants. If you wait for your O2 sensor to come online after the car dies then it'll tell you if there's fuel in the exhaust. If the sensor shows 22.5 then you need to add fuel. If anything else, you'll need to remove it. FWIW, your settings are a bit richer than what I ran with the Flow Force injectors.

Please let us know how things work after trying these changes.

ridethecliche

iTrader: (2)

I went back and forth with Brain et al on this and the conclusion was that the base size is what it is and the adjustments are made after the fact. It's a 640CC injector, but it has higher fuel pressure than what it's rated at so it can push 739CC, but it's still a 640CC injector. So I'm not sure what to make of that.

I thought I got my dead times from one of nigel's old posts so I'm a bit confused as to how I got it wrong. Thanks, I'll double check my settings.

However, this issue is weird to me for a few reasons, the biggest of which is that this is a new issue. The car has been running absolutely fine till now with these injectors. Including with the turbo setup. I don't even think the temperature swings have been all that drastic since I drove it a fair amount when it was warm out a month ago. It does it when it's cool out too.

I don't think I have inconsistent fueling so much as that there's something in the startup/cranking settings that seems to have changed (?) or seems to not be dialed in anymore. This seems to only be a startup/cranking problem.

Edit: Look at the first 10 seconds of the log. That same thing happened this morning twice. Then it started up on the third go around.

aceswerling

I can't comment on what might have changed since I'm a total noob compared to most on here. I simply wanted to share what fixed some of the same problems on my car in the hope it could help. The incorrect dead time settings created the most problems for me at startup and idle. I remember Curly telling me that dead times need to be totally correct under those conditions because that's when precise fueling is most important.

FWIW, I went through several iterations on the dead time settings with the Flow Force injectors, including working directly with Nigel. He sent out a set for additional testing and found they behaved differently than he first thought. This additional testing also resulted in the small pulsewidth settings. Nigel told me before that the numbers on his website are the latest and greatest.

Just my 2 cents...

ridethecliche

iTrader: (2)

My injectors are also not 'technically' flow forces. I bought a set of 8 mustang take offs and bought Nigel's adapter kit. He had commented a few years ago saying that all of his testing had shown an incredibly small amount of variation and that he was confident that picking a random batch of 4 injectors would yield something that would be within 3-5% of one another.

If I had to do it over again, I may have just bought everything from him. But... you know....

aidandj

iTrader: (5)

Required fuel doesn't matter. If you change it now you will need to adjust your fuel table. It's just a multiplier.

aceswerling

aceswerling

ridethecliche

iTrader: (2)

Out of curiosity, what are the symptoms of a cranky fuel pump?

aidandj

iTrader: (5)

Shitty fuel pressure.

Oddly I never had heat soak issues with my mustang injectors. Id1000s have it real bad. It's only at low pw though. So I just run ego correction down low.

I would shy away from letting ego correction take care of it in boost. In my experience it's the low pulse width where the issue shows up. So even if you do a hot restart, then do a full boost pull you will hit your targets in boost. Even if your idle is lean

DNMakinson

iTrader: (3)

@Nigel & @aidandj

Where does MS apply the Small Pulsewidth Correction, before or after Dead Time is added in the fueling equation? I would think it would have to be after, based on the size of the values.

Also, Aidan is correct, injector coil temps affect actual injector Dead time, so only affects low pulse widths in any meaningful amount.

ridethecliche

iTrader: (2)

I think you're actually right. I believe I got the info from his posts and not the site. Ill double check things and look into it when I get a bit more time.

Thanks!

ridethecliche

iTrader: (2)

I'm going to bump this thread in the hope that this gets answered.

Also wondering if anyone has spent some time playing with engine state settings and has a good way to get things to work.

Aidan had a good suggestion for doing things earlier in the thread and I was wondering if there was anything else to add to it. https://www.miataturbo.net/megasquir...5/#post1406629

DNMakinson

iTrader: (3)

Pretty sure it is after dead time, based on info from ID, and what makes sense.

I'm a fan of 1.4.0 or 1.4.1.

ridethecliche

iTrader: (2)

Not sure what issues, if any, I'd run into downgrading firmware. I got the tune working pretty well on my old motor, but the engine states didn't carry over to the new motor obviously.