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Location:
South Australia
Registered:
July 2002
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EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 10:52
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Well, I'm still in the process of building up the 2.2L 3S-GE (using a 5S-FE crank) - I have decided (against my budgeting plans) to go with a custom intake system, and a custom efi system.
I'm currently trying to sort out if I can use some kind of open-source ECU like the MS (as it's the cheapest option) however although I am not ignorant of electronics, I am NO genius when it comes to PCBs, transistors, diodes, circuit diagrams etc etc and it seems like in order to make a MegaSquirt control both fuel and spark delivery might be painful...the other option is some kind of MS derivative...the GenBoard or something?
I was under the impression that although AFM is less 'precise' than MAP, it is more 'accurate' for measuring air flow (remembering the difference between precision of measurement, and accuracy of measurement). AFM is also less responsive than a MAP, apparently, however I do want the engine to be able to run for many thousands of kilometres and thus wear etc etc may become an issue?
Plus if I include EGR (see below) the MAP becomes less precise (as the pressure reading will include some very low O2 content air) unless you include a wideband oxy sensor in the intake tract as well ($$$). Whereas with an AFM, I'll always measure the amount of 'normal' air coming in (thus not being affected by EGR)
Why am I bitching about this? Genboard and MegaSquirt have on-board MAP...*strokes beard* not so cool...
I'm going to run a distributorless ignition, so as to avoid having the distributor punch a hole in the firewall of my TA-23 (the 3S-GE head can be a bit painful to fit when N-S). Using two coil packs and sparking at every revolution.
Here's my short list of things I'll need. Some of which I may already have handy, some not.
- Custom intake manifold
- ST162 Air Flow Meter
- 4 x standard ST162 injectors
- ST162 fuel rail
- 2 x ignition coil packs
- intake air temperature sensor
- water temperature sensor
- exhaust lambda (oxygen) sensor
- idle speed control valve
- throttle position sensor
- cold start injector
- cold start sensor (?)
- some kind of ECU for all this stuff!!!
Here's the stuff I may also want
- Knock Sensor
- Brake Sensor
- EGR (need legal emissions!) + EGR temp sensor
So - question - what ECU options have I got? I don't mind dicking around with an open-source one, I'm a very competent assembly language programmer, but does anyone have any experience or suggestions to add to the list of bits I'll need?
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Location:
VIC, Sth Frankston.
Registered:
July 2003
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 10:59
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assembly rocks 
iv built megasquirt before, its not rocket science, the guide provided on the site is very easy to understand and you just go thru it step by step.
as for a wasted spark ignition system, you maybe looking at using EDIS-4 (if you can find one!)
another option is ultramegasquirt, depending on your timeframe, its rumored to be released 1st quarter in 2005.
there are alternatives for wasted spark/multi coil setups, i just cant think of them 
also, changing your ecu beyond stock is also going to effect your emissions too. just try to hide the ecu away from prying eyes and you should have no problems 
cheers,
James
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Location:
Brisbane
Registered:
February 2003
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 11:09
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a few points you might want to consider
MS to deliver spark and fuel is very do-able (there are vaious options, see www.msefi.com). I'm going MSnS + EDIS in my RA40 turbo
onboard MAP is not an issue - and if you really find this a concern, find a suitable GM under-bonnet MAP sensor and wire it in remotely. MS users suggest there is no benefit or difference from running a solid state map sensor with a few feet of pipe between sensor and pipe.
if you any kind of closed-loop EFI then the need for EGR is gone? the whole point of having EFI that monitors O2 in the exhaust and allows the ECU to try to keep AFR ratios at Stoich aleviates the need for solutions like EGR that try (badly) to control the air-fuel mix.
you can ditch the CSI and EGR and choose from MS, genboard going right up to haltech, motec, autronic, delco, etc they all do the things you want to do.
knock sensors tend to be designed to suit the engine - each engine block will have different harmonics expressed in any knocking/pinging sounds - and hence a knock pickup from engine X may not work in block Y and you would then have to determine which frequencies to monitor.
brake sensors? do you mean brake pad wear? or speed sensing (for traction control)?
what you havn't covered (and might not need) is:
-thermo fan control
-water and/or methanol injection (if appropriate)
-shift light
-logging
-remote/handset control
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Location:
South Australia
Registered:
July 2002
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 12:21
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Dammit, I had a big spiel here but now it's disappeared...oh well have to write it all out again!
It's not that I'm totally against on-board MAP, it's just that I'm against MAP in general...also I have an ST162 air-flow meter + box lying around and it would save me some cash to make use of them! AFM does have it's advantages (as stated) in regards to the change in air flow of an engine as it gets older...
My thoughts on EGR -> EGR isn't just a matter of controlling the a/f ratio...it's a matter of controlling combustion chamber temperatures. Only problem is that most EGR systems are kinda screwy and require lots of crazy bits like pulse width modulation regulators and stuff...it may be a bit of a headache to do, but I'd really like to keep emissions to a legal level for most operating conditions!
If this (EGR) is not possible with these ECUs then I guess I'll have to ditch it...what other methods are available to control NO(x) emissions (ie high combustion temperatures)?
Cold start injection - how do most cars deal without it?
As for logging, I'm not overly fussed...aside from an RPM signal and preferably some kind of diagnostic port any other logging functions are a bonus.
The brake sensor, is more or less just a brake switch, to tell the ECU that the car is braking, and thus applying a correction to the fuel/timing.
Water/methanol injection isn't a priority seeing as the car is NA 
As for the whole ignition debacle. I went to the MSEFI website earlier today, there were about three options for distributorless once per rev spark systems. One was an earlier version of the GenBoard (which is how I found the GenBoard) the other made little or no sense to me but looked like just a minor revision of the software & hardware. THe third option being EDIS, which I'm still convincing myself of, does anyone have any links to further information - it's cool if you don't have one on hand I'll just go for a search
I'm guessing I will need some kind of CAS for the ignition (forgot to write that up).
Lastly - knock sensors. I'm interested in these because I'm planning on running a fair bit of compression (in the range of 10.5 : 1) and thus knocking on 98 octane fuel may still be a slight possibility especially as the engine gets older or dirtier (clogged up with carbon and 'shit').
Bosch have knock sensors, as for what frequency the 2.2L 3S-GE would require to monitor your guess is as good as mine Experimentation would solve that, although I am also under the impression that 3S-GTEs had knock sensors (on later gens? I haven't yet checked my gen 1 ST165 3S-GTE for one but I'm sure I could find out) the later gen 3S-GE might also have a knock sensor - but even that may 'ping' at a different frequency - seeing as it has 86.0 x 86.0 dimensions and the engine i'm building has 90mm x 87mm (stroke * bore).
This is all I can think of for now
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 12:36
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| FWDboy wrote on Wed, 13 October 2004 22:21 |
I'm against MAP in general...also I have an ST162 air-flow meter
what other methods are available to control NO(x) emissions (ie high combustion temperatures)?
Cold start injection - how do most cars deal without it?
As for logging, I'm not overly fussed...aside from an RPM signal and preferably some kind of diagnostic port any other logging functions are a bonus.
As for the whole ignition debacle. I went to the MSEFI website earlier today, there were about three options THe third option being EDIS, which I'm still convincing myself of, does anyone have any links to further information - it's cool if you don't have one on hand I'll just go for a search
I'm guessing I will need some kind of CAS for the ignition (forgot to write that up).
Lastly - knock sensors. I'm interested in these because I'm planning on running a fair bit of compression (in the range of 10.5 : 1)
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ok.. MAP is pretty good in general, but you can make the MS work with AFM also.. it's just a matter of calibrating the signal to be 0-5V i guess.. the MAP is good as it is easy to work with in terms of understanding whats going on.. whereas % of AFM is a little more vague.
control NO(x)?? lower compression ratio
cold start injector? you don't need it if the ECU can change pulse width based on temperature correction and afterstart enrichment (like MS does) cold start injectors are pretty archaic in EFI terms.
logging. MS can log all it's parameters (when hooked up to laptop/PC) and is only limited by your hard drive size. sample time can be around 50ms i think? depends on your serial port i suppose.
ignition..
Megasquirt n spark
Megasquirt n EDIS
Megaspark
Megajolt light junior
the first two are software change and use standard MS to run both fuel and spark. MSnS will run a dizzy based ignition, MSnEDIS will run wasted spark.
Mspark will run EDIS or dizzy based, and MJLJ runs EDIS (i think)
for the EDIS, you will need a 36-1 tooth wheel (like lots fo fords have) and a VR sensor. for the others, you can use points as the trigger, or halleffect, or VR dizzy
hmm high comp and low NO(x) hmmmm... performance AND emissions is always difficult. you do have a cat right?
Cya, Stewart
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Location:
South Australia
Registered:
July 2002
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 12:58
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Yeah - I wasn't aware of the archaicness of CSI I haven't worked on any EFI engines after about 1988 designs.
I am aware of the effect of high compression on emissions - bit of a bummer I know, which is why I'm keen to keep combustion temperature low.
Catalytic convertor is on the cards, yes - hopefully a VERY good catalytic convertor I dunno about using two though, that would suck a mountain of nuts.
AFM is a little tricky yes, and it would require to change the code in the ECU, right, as it is a logarithmic scale?
What exactly is EDIS if anyone cares to give me a quick rundown?
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you will need a 36-1 tooth wheel (like lots fo fords have) and a VR sensor
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36-1 tooth wheel, talking about starter ring, right? And the VR sensor is a bit of an unknown to me - like I said in the title of this thread - I suck!
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Location:
South Australia
Registered:
July 2002
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 13:05
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Oh - had a brief look, MegaJolt Light looks like the way to go at a glance...still looking through though.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Location:
Brisbane
Registered:
February 2003
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Location:
South Australia
Registered:
July 2002
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Re: EFI Design - 4cyl GE L-Jetronic (I suck!)
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Wed, 13 October 2004 13:25
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Ahh I'd have to agree with you on the MS2 - I may end up getting that depending how long it takes to build up the rest of the engine.
I see what you mean about the 36 tooth wheel, doesn't look too evil  And I found out what the VR sensor is too
Cheers for the links!
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Location:
South Australia
Registered:
July 2002
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so I'm not sure what advance it runs.