MicroSquirt.com read only forum (Jan.15,2018)

Earlier tonight I tried to get the engine started with the sequencer running the ignition and my MS2 controlling the fuel. This is a temporary setup as I am waiting for mouser to deliver some delphi connectors in order to connect the sequencer into GM fuel rail harness without hacking it up.

The sequencer is triggering off of a 36-1 trigger wheel I used to run EDIS. In order to get fuel I needed a tach pulse on the MS2 so I connected the tach out from the sequencer into the opto tach input circuit on the MS2 .. while cranking no tach on the MS2 but I have RPM showing on the sequencer so I'm thinking the sequencer code is not driving the tach out in cranking mode.

That is 1 thing I must admit that I never tested on the bench, the tach out... Maybe Scott can chime in if he hooked up the tach out when he got his running?

I've had some delays in getting my car wired & fired, I am waiting on the 7way delphi plugs for the LS1 coil packs and my 'run around' car was stolen last Friday so have delegated alot of time securing everything else. I'm praying the connectors will be here this week though!

Kris

The tach out, which is pin 35 of the Input side Ampseal works in both cranking and after-cranking modes and puts out a 12V square wave. However, its width is about 150 microsec. I don't know if this is long enough to trigger the MS2 opto in, but it seems as though it should be - it is > .1 ms. A 60 tooth wheel at 5000 rpm has a duration between teeth of .2 ms. For a 50% tooth duty cycle this would be a high duration of .1 ms and we know there are many cars out there running 60 teeth at > 5000 rpm, but I don't know what tach input they are using.

The source of the tach out is the TachO signal from the main processor. This signal goes to the sequencer processor as a trigger and MUST work if you are to get any ignition / fuel outputs. It is also teed off to a transistor that is held high by 12V raw and the collector of this goes to pin 35 (tachOut) of the Ampseal.

On the good side, I saw a short snip of Marc's cranking datalog and he has a good tach synch on the sequencer, so it should be firing spark.

After fixing Q1 on the sequencer - I was able to get a RPM signal on the MS2 which is running the injectors for now. The engine started but is running quite rough but its a start to sorting out the ignition side of the sequencer. I do not have a cam signal hooked up so its firing the engine in wasted spark mode. Time ran out tonight to sort what is causing the rough running. Another round tomorrow.

If you are running a bit rough with the sequencer running ignition only, take a look at a timing light.

When I went through my IGN issues (I think the thread was titled 'hard cranking is an IGN issue'), one of the culprits was noise introduced into my Map signal wire. I was getting nutty ignition pulses even though the log and MegaTune was reading the timing I wanted. The problem was that the Map wire was too close to something it didn't like. This introduced some funk into the 5v system (I think).

With this noise introduced , I was able to get the car started, but when it started, my timing mark was jumpy a little bit. Not so much that it was alarming (I thought it was possible that it was just from moving around the ign map), but after I re-routed the Map wire and fixed the noise problem, the timing mark was rock solid.

I've been out of town, but I'll try my tach signal to my tach before I pull the temp wiring for final wiring and splicing.

Do you have any idea what caused Q1 to blow? I think you have this set up to trigger the opto. This should not draw more than say 20 ma or so, the MMBT2222A transistor peak current is 1amp.

If it still gives you trouble triggering the opto, you may want to try the VR input and use the VR Offsetter circuit...

- Bruce

Bruce,

When I had D1&D2 bypassed on the MS3.0 board and trying to trigger off of the sequencer I noticed the IAC stepper driver was getting hotter (wet finger sizzle temp) than normal with no load attached (the IAC is disconnected). Maybe we had a odd interaction between the 12V power supplies ????? Once I replaced Q1 with the ZTX450 and re-installed D2 on the V3.0 its fine. I agree that the 2222 should not have cooked.


1st attempt
The hook up was - seq tachout >>>> MS3.0 opto input jumped to C12 0.001u/pin1 on 4n25 (R12 lifted). Noticed the IAC stepper driver getting hot - no tach pulse. checked seq tach out no pulse with no load. Found Q1 CE shorted.

2nd attempt

Hook up is seq tach out >>>>> MS3.0 opto input, D1 bypassed (jumper), C30 1 pin lifted, D2 installed. R12 bypassed (jumper). This works fine.

After several delays due to mechanical issues, the vortec 4200 roared into life with spark being provided by the sequencer and fuel by the existing MS2 box.

Next up is to move the fuel control over to the sequencer. The same power supply issues that Monkey had trying to start are showing up here as well so until I can get a 1F cap I'm running the sequencer from a 12V bench supply. Bruce mentioned that a permanent fix is in the works for the production boards.

ca434sbc4 wrote:... The same power supply issues that Monkey had trying to start are showing up here as well so until I can get a 1F cap I'm running the sequencer from a 12V bench supply.....

congrats on getting fired up.

what symptoms are you having for power supply? i had 3 items:

- the problem that Bruce is fixing is the voltage dip when starter engages - should be able to still fire up okay if you are getting that; just unsync'd IAC.
- my other problem was due to routing of wires - map signal wire too close to power sources - created funky dwells - reroute fixed it.
- other thing that i used a big cap for was on the ignition power wires to keep ignition spikes from showing up elsewhere - never really caused probs though, i just wanted to get rid of spikes.

for the first reset problem, i tested a new power chip for Bruce last couple days that got rid of reset; reckon Bruce is just working on configuring it to work with the board for production.

Very hard to start on the vehicle power system. The processor resets during cranking. I need to add some cap's on the switching power supply to help this issue. The ebay vendors that sell the 1F caps won't ship to Canada !@#$. I'll dig around the electronics suppliers to see what i can come up with.