mobythevan
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Posts posted by mobythevan
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That must be why alcohol never caught on in racing
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With the test light on the dizzy wire side of the resistor, spin the dizzy slowly by hand and you should see the light turn on and off as the slots in the dizzy pass through the optical encoder.
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That looks like it turned out nice. A good use for the 81 crank sensor for people that have them.
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Here is the text from the sticky about pullups, you will be fine using a 1/4 watt resistor. It needs to be attached to the correct wire fromthe dizzy and then to a 12 volt source that has power during cranking and running.
*Pullup/Pulldown resistor quick course
You use a pullup resistor to get your line(or pin,connection) to some voltage (5,12, etc). Suppose you want a pin to have 5volts. If you just add a wire to 5 volts there is nothing to limit the current and if the pin happens to be an input to a transistor that is switched to ground then you have a short to ground from 5 volts and you burn stuff up. So instead you add a resistor to the 5 volts and the resistor will limit the current according to ohms law. Current is voltage divided by resistance. If you put a 1k ohm resistor to 5 volts then if the pin is switch to ground by internal electronics it can only draw 5 milliamps max(the resistor current-limits the path).
A pulldown is similar except that you want a pin/wire connected to ground and you want the path to be current limited.
To size the pullup or pulldown correctly you should know what the circuit is that you are adding the resistor to. But as a general rule you can use a 1k resistor for 5volts and a 2k resistor for 12volts. That limits the current to a few milliamps which is conservative. Sometimes the circuit may require more current to operate properly.
For the pullup resistors I am just using 1/4 watt resistors.
I=E/R I=12v/1k I=.012 or 12 milliamps
P=I*E P=.012*12v P=.144watts little over 1/8 watt
I=current
E=voltage
P=power
R=resistance
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I have problems starting my car when the temps get below 5 degrees F.
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Ha, are you talking about coming down for the meeting of megasquirt people? It would be neat to see everyone.
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You should be good, it is just the light reflecting in those empty holes that made me think leads were sticking through.
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OK, just checking since it looks like the leads are they, just not soldered.
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Just caught my eye and has nothing to do with your question, but it looks like a couple parts are not soldered? I circled them below.
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There isn't really a control for the fuel pump. There are the rev limiter settings which yours look OK, the overrun settings which you have turned off(that is OK), decel settings look OK, and the over boost setting which was not correct. How do you know the fuel pump or fuel is being turned off? That doesn't fit with the original description of going rich.
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I finally picked up a commuter car so I am not depending on my projects to run all the time. Its a civic hx and while it is not exactly a fun car it did get 43mpg on the first tank commuting.
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Or power used for pullup is only on during run and not cranking?
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reading his post I think he already fixed this. It use to be set to narrowband and he changed it to wideband so megatune matches the gauge in the car.
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I don't think that we set up the overboost limit, so I assumed that 0 disabled that function as in many other places in megatune. Do you think that this might be the root cause -- spark being cut right out of the gate and fuel being dumped into the exhaust, then ignited once the spark resumes?
I don't think so, but 0 isn't valid for that option. If you look at it you will see what I mean, when you try to close the window megatune will complain and then put a default value in there. Certainly set it to 200kpa or 255kpa and try again just to make sure. I would be more inclined to believe the big jumps in the VE table are causing some issues with fuel jumping too much. I would add some more bins for kpa so you have a smoother transition from 30kpa up to 100kpa and then try tuning again.
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I looked over the msq file and I only see a couple general things. One I am not sure if it is real or just didn't load correctly when I opened you msq, but the setting for overboost rev limit was 0 kpa which is not valid, it should be something like 200kpa or were you want spark cut on too high of boost.
These probably don't have any impact but just observations: the spark angle is low for idle for an L28ET, you have 15 it is more like 23 on the stock setup. The fuel table only has a couple bins beow 100kpa. You will probably want something like 20,40,60,80,100 etc or you will have a lot of trouble trying to tune for cruising which is were you spend most of the time driving on the street. Maybe this is causing too big of a jump and causing some of the problems with it going rich, I am not sure.
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Post the msq file if you get a chance so we can take a look at it.
EDIT: nevermind, I see it is coupled with the datalog
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Why is the throttle position dropping when this event occurs? Are you just letting of the pedal as soon as it happens?
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The spikes are still there and they seem to be causing some trouble. Try the shielded wire to get rid of them and if that doesn't work look at what the EDIS guys do to run from their VR sensor into megasquirt.
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Having knocked the idea, I wouldn't mind doing something similar. However, given that I can check my average mileage upon fueling, I can just look at a wide or narrowband O2 to determine when I'm running leanest and consequently getting the best mileage. Agreed?
I thought at times I would be getting betting mpg by being in 4th gear climbing grades and in reality the gauge shows I get better mpg being in 5th gear unless it is a really steep grade. But I agree that you can watch a vacuum gauge and O2 gauge to know where to drive to get the best mileage.
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The instant mpg gauge I added used rpm, tranny and diff ratio, tire size, inj pulse width and injector size to determine mpg. Like I say, it works pretty good, but you have to make a gauge for each gear you want to see so I only did 4th and 5th.
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I put a 4th and 5th gear instant mpg gauge in megatune using equations I found on ecomodder.com, it works pretty well. The overall mpg number is probably not accurate but it shows you were you need to be driving to get the best mpg.
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The only thing I see in the msq is the injector staging set to simultaneous. That always made my engine idle bad. I used alternating.
In the log I can see the spikes on rpm, you should try to clean that up if you can. Are you running the VR pair from the dizzy all the way in to the megasquirt box?
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When the car is warmed up will it idle on its own? If not you may need to adjust the butterfly so it is opened more for idle. What AFR do you adjust to at idle? To rough in a tune I have someone drive the car around while I look at the laptop. In Megatune I watch the AFR and adjust the VE table on the fly. Once the tune is roughed in I have been using megalogviewer to take a 30 minute log and the do the VE analyze. I don't take the changes from VE analyze completey, I then look at them to see if the make since and smooth the table out accordingly.
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You said in the first post that the car goes lean during acceleration, but you said the AFR goes to 8 which is rich. Would you clarify if the car goes rich or lean under acceleration, that will make all the difference on what could possibly be wrong. If the car is going lean it could be a bad fuel pressure regulator. I had a bad one and the car would rev in neutral fine, but at about 3000 rpm when boost would just start to build it would fall flat and run out of fuel.
e85 lq9 Z
in Gen III & IV Chevy V8Z Tech Board
Posted
Anyone that would run race gas on the street if it was legal will want to run E85. You will be able to run as much boost and more timing with E85 than race gas. You will make more power. If you think that is only worth it on the track then I'll just scratch my head and agree to disagree with you.