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I am running br8es gaped to 0.18 - 0.19 . I also tried br9es. It is running on spoolinup coil on plugs denso coils. Afr on boost is 11.7 - 12.0 but when has misfire afr spikes to 12.4 - 12.6 for split second. Timing is similar to my c16 tune around 6 degree at 6000 rpm and around 13 at 8500. I think it is pretty low timing for e85. Should I change my coils to gtr coils or problem is somewhere else.
I am running br8es gaped to 0.18 - 0.19 . I also tried br9es. It is running on spoolinup coil on plugs denso coils. Afr on boost is 11.7 - 12.0 but when has misfire afr spikes to 12.4 - 12.6 for split second. Timing is similar to my c16 tune around 6 degree at 6000 rpm and around 13 at 8500. I think it is pretty low timing for e85. Should I change my coils to gtr coils or problem is somewhere else.
Your plugs, gaps, COP and AFRs all sound good. Run a pull to misfire, chop the ignition, then immediately pull the plugs and take a look. (a.k.a. Plug Chop) Post pics of the plugs along with the log.
Upping boost from 35 to 45psi changes combustion dynamics a lot, and it increases demand on your ignition system significantly, especially at high revs.
Did you check the little springs in the Toyota coil boots are contacting the tops of the plugs?
Did you upgrade the stock power wiring yet to improve voltage at the coils?
Did you change the OEM dwell settings to optimize for the Toyota coils?
If so, you may be at the limit of the ignition system and need to consider upgrading to a CDI system.
It could also be a partially blocked injector that is causing a lean misfire - pull them and clean them.
Less likely is a compression loss on one or more cylinders - run a compression and leak down test.
Just checking....you really mean 0.018 - 0.019 inch gap right
Last edited by CDrinkH2O; Jul 19, 2021 at 11:08 AM.
Thank you so much for your reply. Yes sorry I was meaning 0.018 - 0.019 gap. I did cleaned injectors 1 moth ago because I also though this could be the problem but cleaning didn't fix the problem. I did leak down test and also compression test. Compression is in 160-170psi range. I am using stand alone Autronic Ecu I dont think this ecu has dwell settings but it did worked fine on c16 fuel. I did installed the wires and coils that came with the kit. Do I need to upgrade wires that going to ecu also? I just purchased the kit from spoolinup ( wires, coils). I did checked the springs in coils and look like it is contacting plugs. I will put new plugs make couple pulls and post picture here. But new plugs never misfire , they will start misfire after 100-150 miles. Also I can post log but my log doesn't log afr, I just have 2 widebands installed in car that I am watching them. I also changed both wideband sensors to make sure I have correct readings. Last time when I pulled plugs couple days ago I noticed cyl 3 and 4 spark plug porcelain had a little black smoke (sooty, charred) spot on the porcelain. I dont see my coolant pushing to the reservoir so I dont think I have head gasket problem. How possible is it that heads is lifting and coolant is pushed to the cylinder?? I am just thinking about anything possible. I have arp custom age 625 head studs but its always possibility. Thanks for all help. I am just tired to change plugs every week. When I was on race gas c16 I had to change plugs but maybe every 1000 miles which is normal with leaded fuels but 20$ a gallon was killing me to just drive around. I have more fun now on e85 because I can enjoy the car every day but I need to get rid of this misfire to fully enjoy it.
Pictures of a plug chop on new plugs will give an indication of whether the heat range is good from the color of the ground straps, and AFR lean/clean/rich from the color of the base ring.
If you are still on stock coil power wiring, the voltage drop caused by resistance to the ~15 amp current draw, could be failing to charge your coils fully.
It's possible that you have a HG leak into the cylinder, but you usually see coolant push to the reservoir and/or white smoke in the exhaust. If you want to check for sure get a pump with a pressure gauge that screws in place of the radiator cap. Pump it up to 20 psi and make sure there is no leak down.
If you can't log actual AFRs you're playing with fire at that boost level Figure out how to log your AFRs before you go any further please!
How can you really tell that you are not running out of fuel and that this is a lean misfire? At 42.5 psi base fuel pressure, plus 45 psi boost pressure, plus flow losses (~3 psi), your fuel pump is having to push around 90 psi. Most single pump set ups can't handle those pressures without seeing a drastic reduction in fuel flow.
What is your fuel system? [Pump(s), filters, FPR, size of supply & return piping, injector size, and IDC%]
My fuel system is twin high pressure walbro 450 pumps. One is primary and second pump is turning on with hobbs switch on around 12psi boost. Fuelab fuel pressure regulator, 8an feed line 6 an return line. Injector fic 1650 with 85% injector duty on around 36-37 psi boost. My plan was to add kenny bell boost a pump on secondary pump to lower injector duty or just switch to 2000 injectors but at this setup and boost injector duty is 85% so I can even raise it a little more to be at around 90% and stop there. The ecu that I am using is autronic smc ecu it is old ecu that was used on rally back in the days. I know this is not the best option but I just dont want to change ecu at that time. It does have logger but it is not logging afr because they used some old sensors that I was not able to find. So my tuner advise to install wideband in car so we can watch afr while driving. To be sure I have correct readings I installed 2 widebands in car so I am watching them while driving. I will check headgasket with pressure pump. I will also put new plugs and make pulls and I will send pictures here. Wires for coils are the wires that came with the kit spoolinup kit. Where I can buy some upgraded wires? Also I know I am not running out of fuel because misfire usually happened at around 6000-7000 rpms and going away by the red line. By red line my afr is not climbing up but it is tuned to be at richer side at around 8500 rpms I see 11.4-11.6
thanks
To get the best out of your COP setup you should consider upgrading the 12V power wire that runs from behind fuse #1 in the junction box under the dash, to the white wire in each stock coil plugs. That power wire is only 1.25 mm2 (~18 AWG) and is not good for more than 10 amps. The Denso (Toyota Yarris) coils that are supplied with most COP kits pull 12-15 amps during the charge cycle. This causes a voltage drop over the skinny power wire and so less energy is stored in the coils as they don't fully charge. It also blows the stock 10 amp fuse #1 and forces you to upgrade to a 15 amp. I recommend you upgrade the power wire to 2.5 mm2 (14 AWG) which can handle the extra amps without a significant voltage drop. This will enable your COP coils to fully charge and give you the best spark possible.
The only to find out what is really going on with the spark is to monitor the coil voltage input and high voltage output with a dual channel oscilloscope. There is plenty of stuff on what you need to do this available on the internet.
If you can find the dwell tables in your ECU, the Denso coils in the COP setup will need around 4.4 ms of dwell time to fully charge. The dwell required to fully charge the stock coils is 3.6 ms. If your Autronic ECU dwell time is set too low, this could be another contributor to the misfire.
Last edited by CDrinkH2O; Jul 24, 2021 at 11:09 AM.
krys88 - It looks like the Autronic SMC has no dwell control and the functional description even says "Four Ignition outputs without dwell control (standard model only suits CD Ignition or Smart Ignition modules. Requires dwell interface option for use with most OEM ignition systems)".
I am so sorry for late response. I broke my t case and I was busy rebuilding it in the last week. The last time I run the car week ago I gaped plugs to .017 and it was fine with no misfire. I know gaping it that low is a band aid but I had to try. So my only option at this moment is to change my ecu for something good like Link g4 or just keep autronic ecu and get cdi ignition system? This might be a stupid question but what dwell settings does and how do you set them up correctly? Thanks a lot for all help!
A little update. I was reading on autronic forums to check if your autronic smc board has dwell settings you need to open ecu to check it. I am using autronic smc 1.99 and some forums told me that this board does have dwell. I opened the ecu and I see there is another board on top and it does say Dwell Interface. So than I opened my autronic program on my laptop and I cant find any settings for this? What is going on. Please help guys!
Ok, After reading some more on autronic forums I found some dwell options on this ecu. I am posting picture. Look like ignition output trig is set to CDI Ignition, but I am not using one. Does it means its wrong?
Jul 18, 2021, 01:08 PM
