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This thread will be similar to some older ones I found of "spark blowout" issues under heavy acceleration but I haven't found a solution which helps my issue.
I have a 2001 VVT engine with a TD04 currently set to wastegate spring pressure of 10psi. I am running the Fab9 COP kit with a new, last December, coil ignition driver module and a 36-2 crank wheel sensor.
This is the first time I've got to running this setup and now I have the starting issues sorted (thanks to you guys) I've been able to get out on the road.
The problem is when I accelerate in 3rd gear, for example, and anything more that 25% throttle the engine begins misfiring like its hitting a fuel cut. When the wastegate actuator so its making almost no boost I can go wide open throttle in any gear at any speed with no issues. I tired changing the static dwell of 3.2ms to table based going up to 5.5-7ms under load with no help.
The tune is pretty much the same as when it was running a NA 1.8 with the same turbo but stock ignition system.
Uploaded the tune and a couple of logs if anyone might be able to see an issue. Thanks in advance.
Unfortunately I cleared out the garage a few weeks ago and for the first time ever I through out all the old bits I might need someday and in that were the OEM VVT coils!
Its a 2001 or 2002 VVT engine installed in a Westfield kit car. Originally it was running a 1994 NA 1.8 so the wiring is all 94. Its been running a Rev MS3 since day 1 with no issues and never had issues on the OEM 94 coils and the NA 1.8 before the engine swap.
Checked the plugs and they are Bosch FR6DC gapped at 0.025" which may be a bit hot? The IK22's the Fab9 kit came with died during my cranking issues. Will try from FR5DC as an equivalent of the IK22's as I can't find Denso or NGK plugs with the removable terminal in the UK easily.
Failing that there is a company in the UK that does a VAG COP kit I could try.
The log seems to show a spark issue and it doesn't appear to be anything commanded by the megasquirt so it looks like a coil problem. FAB9 doesn't seem to list instructions for their kit. Did they even list a dwell time? Changing a sparkplug heat range is unlikely to fix your problem.
I still run stock NA8 coils and have pushed them over 20 psi without issue. Grab a used set of those if your harness is setup for them anyway.
You also need to fix your VE table. Looks like you ran VEAL while it was misfiring so it added a bunch of fuel.
Turn boost control OFF, even if you don't have EBC hooked up. Set Overboost cut to just above your waste-gate pressure.
Just tried this, boost control off and overboost cut to 80kPa, usually 210kPa, to be match around the 10PSI spring in the turbosmart actuator and it was easily hitting fuel cut as soon as you accelerate hard.
Just tried this, boost control off and overboost cut to 80kPa, usually 210kPa, to be match around the 10PSI spring in the turbosmart actuator and it was easily hitting fuel cut as soon as you accelerate hard.
To be fair to you the tooltip is slightly deceptive but the number in that field is maximum manifold pressure, not maximum boost pressure. You have to add atmospheric pressure which is 100kpa at sea level.
Just tried this, boost control off and overboost cut to 80kPa, usually 210kPa, to be match around the 10PSI spring in the turbosmart actuator and it was easily hitting fuel cut as soon as you accelerate hard.
Originally Posted by SpartanSV
To be fair to you the tooltip is slightly deceptive but the number in that field is maximum manifold pressure, not maximum boost pressure. You have to add atmospheric pressure which is 100kpa at sea level.
Set boost cut to 180kpa.
Note: that comment was not to fix this problem. That was to protect you engine at such time as you begin to run EBC, or if wastegate was ever to stick closed. I've seen too many folks break their engines simply because they did not take the 5 seconds to set Over-boost Cut.
The log seems to show a spark issue and it doesn't appear to be anything commanded by the megasquirt so it looks like a coil problem. FAB9 doesn't seem to list instructions for their kit. Did they even list a dwell time? Changing a sparkplug heat range is unlikely to fix your problem.
I still run stock NA8 coils and have pushed them over 20 psi without issue. Grab a used set of those if your harness is setup for them anyway.
You also need to fix your VE table. Looks like you ran VEAL while it was misfiring so it added a bunch of fuel.
Nope, no instructions but the wiring they supply is PNP. They say to have default dwell at 3.2ms and increase to 5.5/6ms under load which didn't help.
Originally Posted by SpartanSV
To be fair to you the tooltip is slightly deceptive but the number in that field is maximum manifold pressure, not maximum boost pressure. You have to add atmospheric pressure which is 100kpa at sea level.
Set boost cut to 180kpa.
Ah that makes sense! I remember seeing a forumla to work out overboost on one of The Car Passion Channels video now.
Originally Posted by DNMakinson
Note: that comment was not to fix this problem. That was to protect you engine at such time as you begin to run EBC, or if wastegate was ever to stick closed. I've seen too many folks break their engines simply because they did not take the 5 seconds to set Over-boost Cut.
DNM
Thanks! I did increase the overboost much higher earlier to see if it was that but put it back to the 210 it was normally at. Boost control table is all zeros at the moment too as I just installed a 10psi turbosmart wastegate actuator.
It has a rolling road tuning session booked in for late April to sort of the tables properly as I know VE is not right.
Some news on the loss of power. I've found a UK company who have their own COP kit which also uses Denso COPs. They use Denso 12900-5150 units and the Fab9 COPs I have are 129700-4400, not sure of the difference. I am running their ignition driver now instead of the Fab9 one.
I ran the spark C and D wires from the MS3 to the ignition module so its now fully sequential instead of Wasted COP and I still have the problem but it now starts at a higher RPM. Before with wide open throttle in 4th gear I would get power loss from around 3000rpm and now its 4700rpm.
I was recommended to run 2 1k resistors, both resistors connect to the 5v pin/wire then to each coil leg for 3 and 4. On their early sequential kits they saw the same issues as what I have which could be due to the triggers needing a logic level and greater voltage to trigger.
Ignition Driver? My MS3 Basic drives my COP's directly. They are Denso 90080-19015. I bought them used. They have the igniters built in. I just ran the wires from the MS3, no capacitor, no nothing else. 3 wires to each COP. IDK. I thought that is what most everyone does. Power, Ground, Signal. 4th pin is un-used. Like this, but no cap used.
My wiring currently looks like this. Coil 1 and 2 are driven by the OEM wiring then I've run the two addition spark outputs to coil 3 and 4. The Denso coils are only 2 pin.
I think the idea is next to add 1k resistors from the 5v sensor wire to the spark 3 and 4 wires like this
02-27-2021, 05:57 AM
Loss of power under heavy acceleration
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