Sequencer almost ready to fire

[krisr]

Hey guys,

Thought i'd throw an update together. As of tomorrow I should be in a position to fire my engine with the sequencer - initally i'm going to be using wasted spark and if I have enough time I'll pull the distributor out and modify it so I can get a cam pulse. Bruce/Al, I really do apologise for the delay, with the rediculously hot weather, changing jobs and having my daily driver car stolen really kicked me in the guts time wise.

I have basically confirmed everything on the jim stim and have pretty much built a final harness to suit my car/engine. I've been very meticulous with the wiring and have kept it away from all the high amp leads. Each cylinder is colour coded and in total i'm running the normal 3 grounds on the green side and 6 grounds on the red side.

Fingers crossed for tomorow!

[krisr]

Well no luck can be had - a brief run down of what happened today.

*) Timing has not changed mechanically, is set at 11°BTDC as per where it was on my MS2.
*) 36-1 tooth wheel, sending a positive going transition to the sequencer. It was getting RPM, now it's not, I think because the battery is now dry.
*) Cam/distributor signal isn't wired up yet - tests on the bench told me that without it hooked up, it will just work in wasted spark/fuel mode.
*) Injector/Ignition wiring is wired up as per;
1-2-3-4-5-6-7-8 (sequencer)
1-8-4-3-6-5-7-2 (firing order)
*) I am using coil packs from an LS1 with dwell settings as per the manual, I've checked the wiring many times now.
*) Engine backfired once meaning something is working.
*) Cranking pulses are set to 40ms/cold and 15ms/hot - possibly too high?
*) Continuity checks out from injector/coil pack plugs right back to where the ampseal is soldered onto the PCB.
*) Could not get reliable signals on a scope or timing light - pulled a plug and could not see any spark.
*) Could not regain comms with MT after the backfire for some reason.
*) Similar power supply issues as Marc/Scott - will try the same cap Marc used across C60 to see if that helps. Will probe more tomorrow to verify it's exactly what Scott had.
*) Did not appear to have any noise on the MAP that Scott had, I have wired up my MAP sensor underneath the dash though well away from everything.

I had tried settings from Scott's MSQ file as we're running relatively similar setups.

Before I go ahead and change the capacitance of C60, i'll put a scope on VREF to see if it's dipping like previously reported. Will keep cracking tomorrow.

Kris

[grippo]

kris,

I will check your msq on the bench, but I know you have already done this. As far as losing comms with MT, I believe what is happening is that there are 2 processors in the Sequencer, and these need to come up together in an orderly way or one will sit around waiting for the other. There are 2 solutions to this - a new power supply that will only need 5.5 V to bring up the processor, and will go down to 2.5 volts before losing the ability to supply 5 V to the processors. This will prevent resets in the first place. The second is to tie the BDM header grounds of the ECU and router processors together, so that if one resets the other will also. These fixes have already been implemented and tested for the production version. Meanwhile, either cycle the key when this happens or better, tie the reset pins on the bdm headers together with a jumper wire. I also found a code problem, which was always there, that required a key cycle to get things going under certain conditions. This has also been fixed in the latest code.

[krisr]

Heya Al, Happy Easter and all that jazz!

I had found 1 problem with my MSQ, which may explain the backfire which made my neighbours come outside - input capture was on the wrong edge . Looking at some of the sequencer threads, i'm still a bit hazy as to what the "# of Injectors" should be or whether it has any bearing in the code - I thought it was just a req_fuel or duty cycle thing but in the original email it said it should eq the # of cylinders, but in looking at one iteration of Scotts MSQ, his is set to 1. Another thing that confused me a bit too, original email said to use "High to Low" on the output, but the INI still says "Going High (Inverted)" or "Going Low Normal)" - I assume the Going High (Inverted) logic is what we need?

I'll definately try tying the header grounds together tomorrow too.

You mentioned a code problem, will this be a fix for the 1st processor or will the unit have to be sent back to have the 2nd processor flashed? If the 2nd, any ideas on how we can possibly "rig" this up so I can flash it here instead of the whole freight to/fro across the pond?

Funny you mention the power supply aswell - I've spent most of the night looking at the LT1676 datasheet and some diagrams i've managed to find, tomorrow I was going to target that bad boy with my scope and try work out how to make it work. An EE friend of mine said that SMPS's dont really like a voltage drop period, so goto town with adding capacitance on the Vin - they found that out when using them with solar power devices etc.

[grippo]

I posted a message right after the last one that said I had tested at your msq on the bench and all looked good on the scope. Also, set no injectors to 1. So you should have 8 cylinders, 8 squirts and 1 injector. The last number is needed to get the duty cycle right - it has no effect on your engine because it isn't used in the code. It is an MT thing that requires a change in the MT code to fix and I don't know when this will happen.

As for ignition polarity, use whatever Scott used in his msq - he has the same setup as you and his works.

Tie the header reset pins (NOT grounds) together (they are pin 4 on each header). I originally wrote Ground but I swear I corrected it to reset, just like I swear I sent a second post - obviously I'm losing my mind. Anyway, this won't solve any of your problems, but it is something that will prevent a lockup.

Likewise there is nothing in the code fixes that is needed for you to run your engine. When you have a running engine and we have tested the hardware, I will send you another unit with updated code in the ECU and router processors - keep the old unit as a backup unless we need it to do forensics - but I don't think that will be the case. If it is I will give you an account number.

And by all means add capacitance across Vin. That has helped everyone.

[krisr]

Ok... progress! I put a 220uf 50V electrolytic cap across C60 and bingo, no more problems with the power supply. Also I jumpered the reset pins on the BDM which didn't really help my comm's problem, but I had found that in my wiring I had forgotten to send the bootloaders to +5V after fixing that gave me back *some* form of comms. I'm having ALOT of issues with comms and I dont know whether it's a noise issue or further inside the unit itself. See the attached log and you'll see what I mean, it makes making changes a real hassle.

The car is now running, sort of. In wasted spark it's very rough and abrupt, putting a timing light on each lead, some are firing, some aren't but I can't be too sure if it's because of a fuel delivery problem (i.e. nothing to ignite) but that shouldn't matter with a dedicated coil on the cylinder. I know with twin posts it can be problematic. Alternatively I could have a dead coil but 7 of them seem to be sparking intermittenly.

Anyhow, i'll do some more scoping and potentially pull out my distributor and setup full sequential but I was hoping that wasted would be a good place to start before "putting more links in the chain".

[krisr]

Thinking about the noise issue more, the way I have wired up the car is a typical "spinal cord" loom, same way I did my MS2. Everything is wrapped together through the engine and branches out, now, I have the power wires for the coils & injectors wrapped up in this loom with the only difference to my MS2 loom is the inclusion of power for the coils. Also with all the ground wires, bolted them all down to the same bolt on the bellhousing, the ground lead to the battery is on the next bellhousing bolt.

Another thing is that i've wired up the coil packs as per the manual but without the cap's so I could be introducing noise here? The signal ground is going back to the "Sensor Ground" wire while the Coil primary ground is going to the intake manifold just adjacent. This may be introducing some back feed noise into the sequencer too.

[grippo]

I'm amazed the car runs at all. You are getting both processor resets (about 5 in the 15 or 20 minutes of running) and constant extra tach pulses. You can see the resets by plotting the time column (PC time from MT) and the secL column - processor seconds which only resets to 0 when the processor reboots. If you plot the rpm and trigger+/- columns you can see rpm constantly going to 0 and the trigger constantly ramping up, except it goes back down to 0 when the resets occur.

So, your comm problems are not comm problems, they are reset problems because the 220 uf cap is still not suppressing all the resets. The resets are similar to what Marc experienced.

The resynchs I need to look at more closely. But you should be able to run wasted the way you have it - I don't think going to sequential is going to make a difference and I wouldn't switch at this point.

Bruce will get back with comments on the wiring - I know he doesn't like coil wires mixed in with ECU signals.

[krisr]

Yeah the engine will not rev at all and the plugs are black so fuel is going in, but there's alot of drama's with getting a bang in the cylinders. I wonder if I have the correct Spark Output, currently it's set to "Going High (Inverted)" but that was for the old VB921 setup. I dont have Scott's latest MSQ so i'm not entirely too sure what his output edge is where his engine is idling nicely and it's too late to go scope the engine without causing a neighbourhood dispute

I spoke to my EE friend again about how the wiring is done and he said that I should scope the +12V and if the supply is clean, then it shouldn't really cause much issues. I'm just a bit concerned that I have ALL of the grounds out of the Sequencer going to virtually the same place. Will wait to see what Bruce says though.

[grippo]

Scott used going high so I think you are ok there.