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 Post subject: Thanks Pierre.
PostPosted: Sun Aug 20, 2017 6:45 pm 
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Yes, I just don't know if that's accessible with the 30003 model or not. It's not clear to me what exactly is adjustable, but there are a lot of adjustments. I called the FiTech guy, they always revert to the baseline, "...is the IAC set correctly." Yes, it is, or was, it seemed to change, at least for me. Anyway, after resetting the IAC, I played with the accel pump settings as suggested but that didn't seem to help. I did tune them down to the point where it was bogging due to fuel starvation, but I can't seem to find the middle ground between that and too much fuel. I'll figure it out eventually, more reading, more playing. I may reset the system and start over. Also, I can data log and send to FiTech, maybe they'll see something obvious that I don't recognize because I'm totally a nubie when it comes to fuel injection.

Brian

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 Post subject: Pierre
PostPosted: Sun Aug 20, 2017 8:09 pm 
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...sent you a PM. b

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PostPosted: Mon Aug 21, 2017 12:58 am 
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The accelerator pump emulation in software is supposed to make things massively rich. If you were to put an o2 sensor on a carb setup you'd see the same thing. You tune acceleration enrichment more by feel and verifying it is rich, rather then exactly how rich. If the software has an auto-tune function, it should be ignoring the o2 sensor during accelerator enrichment periods.

http://fitechefi.com/tech-posts/fitech- ... tructions/

Pay attention to the IAC position at idle and TPS readings. Make sure fuel pressure is steady too - watch the gauges while revving it in the driveway.

Remember, get the accelerator enrichment close enough and drive it. Get the main map right then come back to the enrichments.


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 Post subject: Thank you, Pierre!
PostPosted: Mon Aug 21, 2017 10:27 am 
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Thank you for the tips, more reading for me...b

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 Post subject:
PostPosted: Tue Aug 22, 2017 8:15 am 
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I just finished an EFI conversion on my /6 Dart. I use Megasquirt3 on both my Dart and my Charger. My Charger (440) has been running EFI for about 5 years (I think). It's been through several iterations: carb with EFI sensors, then TBI, then MPFI, then a larger MPFI setup.

Pierre is totally correct in that you generally tune your map ignoring enrichment functions until you are very close to a good map. Then you add enrichment. Both of my cars are currently MPFI, and the enrichment required is VERY SMALL. Like 10% small, even at large changes in throttle position. I'm just not sure how much control you have over that.

When my Charger was TBI, I was never able to suitably tune the accel pump function. No matter what I did, it acted like not enough fuel or too much fuel. Basically, it behaved like a carb. When you tip in, AFR would go rich (11:1) and it would pull fine. As I leaned it out, it would go from that to a lean problem (14-16:1). There was no in-between, so I settled for rich and driveable. I wonder if this is your problem. The O2 sensor can also get confused by liquid fuel, which if it's rich, you may have in your exhaust. With MS3, I have ended up in cycles where the computer sees "lean" because it's dumping too much fuel and getting liquid fuel in the exhaust, which it sees as "lean." You have to be aware and use your eyes and ears too.

This brings me back to another possible issue. The manifold you are using (and me too) is not an EFI-style manifold. Given that you're running TBI, it will probably behave more like a carb than you might like. Even my MPFI has some manifold-related issues (I think). Basically, I think the plenum and runners are much shorter than ideal and the big flat bottom will tend to puddle fuel (especially in TBI). All that said, I think it can work just fine- but not like a 100% EFI-conceived motor. I am considering adding a spacer to mine to add plenum volume and maybe ease that right-angle air flow transition, which might help you with puddling too.

One of the reasons I did not go with FiTech was that I couldn't tell how much control you had of these parameters. I personally know at least one guy running FiTech and loving it. The most important thing to remember with EFI is to tune ONE THING AT A TIME. Disable any sub-system you can work on ONE ASPECT only. So, to start with, be easy on your pedal, disable the accel pump function or turn down as far as possible, and tune your map. Then tune your idle, your warm up, etc.. Finally, add details like the accel pump.

Hope that helps...


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 Post subject:
PostPosted: Tue Aug 22, 2017 9:04 pm 
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I think this was discussed on one of the past fitech threads too... the 30003 is rated 400hp. It's possible the injectors are too big. The injectors have a minimum pulse width they function at - if the computer fires them with anything smaller behavior is erratic. This is usually a problem only at idle or lower rpms though.

You may be able to get away by turning fuel pressure down if the regulator's adjustable in that thing. That will lean out everything.


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 Post subject:
PostPosted: Tue Aug 22, 2017 9:32 pm 
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Ok, just checked - 30003 has 4x 56lb/hr injectors. That's big.... for an N/A engine making 200hp you want qty 6 @20lb/hr (mpfi) qty 4 29lb/hr or qty 2 59lb/hr

Heck you can get away with unplugging 2 of your 4 injectors if the computer doesn't spazz out doing that and depending on its fire pattern.


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 Post subject:
PostPosted: Wed Aug 23, 2017 8:12 am 
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If the fuel command center is 3 bar, you may be able to get a 2 bar regulator. I think I read somewhere they even make a 2 bar fuel command center. If you cut it down to 2 bar, you would be in the neighborhood for fuel injector size. 56 lb-hr should go down to about 45, which is closer.

But, as pointed out by Pierre, who knows what the computer may do if you do that. Just doing some very rough math, it looks like your base time number (talking MS3 terms here) would be around 10ms for your current configuration. That's not that bad of a number. My Charger runs with about 8ms base number, which is low. The issue with numbers this low is that to achieve a pulse width of, let's say, 20%, you're at ~2ms. Injectors can have non-linear characteristics when the pulse is small. "Small" depends on a lot of things, but typically it seems anything under 2-3ms can be difficult to manage. And all that depends on what is in your VE table. Do you have 20% in there? Or is the lowest number 40%? Again as pointed out by Pierre, this should really only affect low rpms, idle, and possibly deceleration.

So: if you're rich all over, it may be something else. Number one suspect: Exhaust leaks, especially near your O2 sensor. If you have leaks, they can suck in ambient air at times and confuse the O2 sensor by seeing an artificially lean condition.


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 Post subject: Wow, thanks Guys!
PostPosted: Wed Aug 23, 2017 9:25 am 
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That's a lot of information but I get the gist of what you're saying. I think there is ability to turn back the PWM of the FCC, not sure that affects pressure though. The FiTech guys said 150 hp up should be ok. I obviously need to read more condsidering your feedback.

Brian

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 Post subject: know a guy with FiTech
PostPosted: Wed Aug 23, 2017 11:16 am 
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dpstark2, is that guy you know running a slant? Maybe you can hook me up with him. Send me a PM if so.

brian

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 Post subject: MAP change maybe?
PostPosted: Sun Aug 27, 2017 11:09 am 
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I decided to reset the system and start again. What I noticed in the reset procedure is that it says, V8 355 cu in is the default. That's what I started with last time, but setting the cylinders to 6, etc. BUT, in that menu there is a V6 setting, so I'm going to try that, perhaps it has "lighter" fuel maps for a V6. I didn't ask the rep yet, but it seems reasonable that it would. i'll give it a try. The trouble with this system is not necessarily the system itself, it's that there doesn't appear to be a comprehensive write up anywhere. There are snippets all over the website, descriptions of settings, logs of blogs, but it's really not easy to find information. Perhaps it's because the system is really easy and I'm a dumbsh_t but honestly they could make finding information about the system way easier with, I don't know, maybe a manual for each model, indexed.

Brian

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 Post subject: Whew!
PostPosted: Sun Aug 27, 2017 2:10 pm 
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Well that was it, basically. Starting from the V6 base settings, I set the system and it works great. I haven't changed any accel pump settings, AFR, nothing, I just wanted to see what it would do, seems fine. No over richness, runs pretty good. I will probably tweak it a bit at some point, but I want to drive it for awhile and let it learn. It does seem to improve over time, idle etc. I'm amazed that the tech guy didn't tell me that V6 setting existed, he said simply to change the number of cylinders to 6 from the base (v8, 355ci) setting. Of course, in retrospect this seems obvious, but I didn't know to even look for such a setting.

NOTE: The FCC is getting too hot. After a 10 mile drive in the 90 degree heat, my low pressure gauge reads zero, very likely fuel boiling in the FCC. The FCC is reading 130 degrees (but it sure feels hotter to touch). I may have to go to a return line system to keep the fuel cool. But that is trivial now that I have the TBI working well. Two options are 1) to modify the FCC so the low pressure fuel pump recirculates fuel back to the tank through the FCC (see: https://www.youtube.com/watch?v=s77BRWlI81c ), or 2) ditch the FCC and go with a high pressure inline fuel pump mounted back on the frame rail to recirculate through the TBI. I'll probably try option 1 first, since I already have the FCC and it is already plumbed for return, just need to modify it and put the return line back at the sending unit where it was.

I will be putting my Webers/intake up for sale soon.

Brian

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 Post subject: base settings
PostPosted: Sun Aug 27, 2017 2:14 pm 
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So, the baseline setup was cu in = 225, PWM for FCC = 40, that was it. After setting the IAC as indicated, I didn't change anything else, idle speed, nothing, works fine. Easy starts, etc.

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 Post subject: Oh yeah, air temp...
PostPosted: Sun Aug 27, 2017 2:25 pm 
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The air box helped on the air temperature. It was running at 120 degrees, now with the air box it is 90-100 degrees depending on the outside temperature.

b

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