mobythevan

You will only have a problem if you are amplifying above the voltage that the MS board uses as input. The normal MS board wants 12 volts from the coil for trigger. You could us an opamp like your experiment to amplify the VR signal up to 12 volts and input to the MS board OK. Keep in mind you would need to run the opamp from zero to 12 volts. A lot of opamp circuits work off of positive and negative supply voltages, like -12v to +12v so your output wave has a 24volt peak to peak swing. As long as you run the opamp from zero to 12v I don't see a problem with putting the signal to tach input on a noraml MS board that expects 12 volts from the coil. RPM will not matter for power, kinda of like PWM at that point. At a high rpm you just have a signal that is getting closer to 12volts, at low rpms it averages to a lower DC voltage.

Measure your NA injectors to see if they are high impedance or low impedance. If they are high impedance then you do not need the dropping resistors ( I thought from memory that they were high impedance but I could be wrong). If you need the resistors, it is one resistor per injector. Look at the schematic for the relay board even if you are not using it. The schematic will show the main fuse value used for megasquirt. I have not filtered the power to megasquirt on my installs. But read through the sticky on resets for general ideas on spark plugs, wires, grounding, etc. Last, I believe the v3.0 pcb has an extra transistor or two that can be used for things like fan relay. The amplification stage (2222 transistor) is not an MSI vs MSII thing, it is more of a v2.2 pcb vs 3.0 pcb issue.

Since you have the v3.0 pcb already I would just buy the MSII processor daughter card and plug it in. That was my understanding, the v3.0 board can be used with either msI or msII.

I can answer one question. If you expect .7 ohms for the primary and your meter leads measure .2 ohms when touching them together, then you will add the numbers. So .9 ohms for the primary sounds correct.

Please do us all a favor and everytime you make a change in the msq file repost it so we can all look it. The last msq I see posted in this thread was on Feb 16th, have you changed any setting in the msq since then? Also, maybe put in your signature what basic things are configured on you megasquirt install, do you use a relay board, do you use dropping resistors, low impedance injectors, etc.

Here is the link to the tuning manual: http://www.msextra.com/doc/ms1extra/MS_Extra_Tuning_Manual.htm

To get the car to idle you should not have any kind of correction or autotune turned on, you should be following the megamanual for tuning to get the engine to start and idle.

I am not sure what path the OP is on, but he doesn't seem to know if his box has any real problems or just data logging to laptop problems. Until he figures that out he would be crazy to start hacking up the box with every fix that everyone suggest. I am not saying that these are not fixes, but the OP needs to get a plan and stick with. A plan that answers some basic questions, like is he really getting noise/reset problems or not. I have read all the threads by the OP and he does not have a solid troubleshooting plan and has not had one since the beginning of this problem. I know he has been trying all kinds of suggestions that are thrown out without understanding the real problems so maybe he will continue that way. This is a very very confusing path to be on. I just want to mention a couple things at this point: 1. If firmware is being lost and having to be reloaded then you have a noise/wiring/build/install/reset problem, no question about it. I have worked through enough installs to see that only the ones with noise/wiring/build/install problems have blown away the firmware. The others that were clean well prepped installs have runs for many years without ever losing firmware. 2. If the laptop log shows battery voltage problems you need to confirm 100% that you have a datalog problem that is causing this or you need to confirm that the battery voltage is bad at the megasquirt box like the datalog shows. 3. If you reach a point where you no longer have blown away firmware, no longer see "real" resets and see good constant battery voltage at the megasquirt board then you are ready for the next step (maybe see if the car idles OK).

Did you read the sticky on reset problems yet?

What is your grounding setup like for the battery/alternator/engine/chassis? Where do you connect the ground cable from the battery? How many grounds do you have from the engine to the chassis? This will start to give us an idea is this is a problem or you already have a good grounding approach.

I would concentrate on chasing the reset/noise/voltage problem, then when you are not seeing any resets and no spikes on TPS or MAP you will be able to tune the car. Read through the sticky on reset problems and start to figure out if any of the suggestions apply to your installation. Also, look at it this way: you set out to use megasquirt and if your install would have worked right away you would not have the chance to learn more in depth troubleshooting. If you take your time and start to lay out a good problem solving plan, this kind of project will help you move up to areas that most people will never be able to work on for their car projects. We all like projects to work out easily, but we rarely learn much from those kind of projects.

Make sure you watch for resets to occur while you are working on the car for the next few weeks. Also read the sticky about reset problems, it goes over many different areas to look into. If the reflash fixed it, so be it. I have a feeling you have an underlying problem that caused the need of a reflash. I had to deal with these problems on one megasquirt install and it took literally rewiring and working on every single piece of the electrical from battery, alt, ground wires, relay board, megasquirt. It wasn't fun, but it started from a shotty wiring and install job and took a long time to clean up. And the ongoing symptom was resets and having to reflash firmware every couple weeks.

You only need one 7 pin (or 8 pin) HEI module to use a VR dizzy with the V2.2 megasquirt. I did this setup in a few chevy TPI engines. The basics are the same, the dizzy used a VR sensor. The 7 pin HEI picks up that signal and sends a trigger signal to the megasquirt for rpm/tach. The megasquirt controls the 7 pin module to fire the coil. Look at this picture from the link that Matt gave for the 7 pin:

Yeah, but not very many calories so don't go thinking that you are going to shave a half second off your quarter mile by drinking ice water all the time

Please don't make posts like that, it doesn't come off good that you ask a question and wait one day then start to whine about no response. I looked at your msq file and one thing I notice is that you have wideband correction turned on, but you do not have an 8x8 AFR target table turned on for correction. I would recommend that you use an AFR target table. You will need to set the ini file for megatune to tell it which type of wideband you have so the gauges will work correctly in megatune.

good one

In the first pic you can see the type of stock stainless header I used and the idea to use it for the collector and then I welded pipe to it and crossed over (not in this pic). For the drivers side I used the same exact stock stainless header (I used two drivers side headers from camaro). This time it is flipped so both sides exit forward, one down and one up. It was a low cost system that ended up matched length and works well for me.

I just bought some of the stainless steel early camaro headers (I think 98 style) and used them for my turbo setup on my LSx RX7. But, if you don't have a welder and some fabrication tools I don't think you will get far.

You are tuning idle with the engine completely warmed up right? Otherwise warm up enrichments will be going and tuning idle won't accomplish anything.

Good to hear. Now whats the next upgrade?

I like Inside the Fire by Disturbed. I can't get that song out of my head for days when I hear it.

Looking at you msq, maybe it is not loading correctly for me, but just to verify: Under "crank/warmup", then under "more cranking stuff", what is your "cranking RPM" and "TPS value for flood clear"? Like Zmanco pointed out, the cranking rpm is loading as zero for us. I also see the flood clear as zero. If that is true I think when you are cranking the car megasquirt thinks it is in flood clear all the time(the TPS at rest will read some raw value above zero from my experience, usually less than 30). That would explain why it won't fire any more even if it gets spark. It is only getting the priming pulses I guess and nothing more. This value should be something like 200. Let us know if your megatune show a zero for both of these. If it does, set cranking rpm to 300 and flood clear to 200. That won't fix any spark issues like Zmanco said, but these need to be fixed or it won't fire up correctly and transistion into ASE and WUE smoothly. Maybe the msq is not loading correctly for us. Otherwise settings look in the ballpark and I don't see anything else obviously wrong.

Post your megasquirt settings file (.msq) so we can all look at it. I want to see what you have for required fuel, priming, ASE, WUE and VE table. Tell us what code you are running (MSNS_extra, hi_res, what version)

I am pretty sure what he meant is when you hook up megasquirt, you start with very basic things like this: 1. Calibrate TPS 2. Calibrate timing between table and engine (timing tab, timing light) 3. Set required fuel by using the calculator for engine size, injector size, target afr 4. Now follow the megasquirt manual on firing the engine and starting to tune cold start, after start, warm up. 5. When the engine is warmed up start working on fuel table adjustments. I think the previous poster just meant that calibrating the TPS and calibrating the timing happen right away before even trying to fire the engine for the first time. It is a large project to tune everything on your car for the first time. It took me about 5 cars before I started getting the hang of it. Now I know the process really well and can go from first firing to tuning the VE table in little time, but every car has different problems so any kind of guide doesn't address every problem. Best advice, follow the mega manual for tuning and think about why they tell you to turn off correction to tune AFRs, turn off accel enrichment to tune AFRs, have a warmed up engine before tuning AFRS, etc. Accell, warm up, ve should all be tuned independently. I really messed up some ve tables early on by tuning with accell enrichment turned on. Just keep at it is all I can say. EDIT: I notice you are 8 hours from me. Maybe load the car on a trailer and plan a weekend at my house. Tuning party!

I put together an engine similar to what you describe in the past, but I had flat top pistons with the small 57cc combustion chamber and the compression did not come out as high as I hoped. Like was pointed out, once you figure in how far down the hole the piston sets at TDC and gasket volume plus other small details you fall short. But it will still run good at 9:1 and be fun to assemble. I also understand Doc's input, because given what I know now I would not put any sbc engine together without a decent set of heads. But given what I know now I only work with gen 3 or newer chevy engines unless your talking big block.