for the 1st time I'm seeing ignition advance and retard spikes in my data logs. No key word searches that I can think of come up with other ppl having this problem. It does not happen all the time; just randomly. Here is a picture of one of my 4th gear WOT pulls. What could be causing this?

 

That's really weird. Corrupted cell in the ignition map?

Otherwise must be some other ignition compensation parameter that has gone wacky. Probably compensation based on a faulty sensor reading. You'll have to check all of your inputs and look for anything that correlates with the spikes.

 

which version board is this with?

 

Make sure your connection between ECU and computer is solid. Looks like it's corrupting data in the connection between ECU and computer.

Idk why but I seem to remember Honda S200 doing this too. I think it's how Hondata handles null or invalid data.

 

the only thing I can see that would adjust ignition timing up and down is ignition voltage compensation. Oddly enough there are small changes in voltage as the ignition spikes, and you can see the voltage compensation data cell move at the moment of the spike. BUT there are similar and equal voltage changes in the datalog where the voltage compensation does not seem to have an effect of cause a spike.

Here's a few more pictures of the same log with Bat voltage added. Notice the ignition voltage compensation scale at the bottom with the white highlighted cell shifting. It's the only ignition compensation or sensor I can find that shift as the spikes occur.




Here's the negative spike.



when I 1st saw this I thought the voltage compensation was it, but as you can see the batt voltage fluctuates all the time and the timing spikes are random to the batt fluctuations

Do other cars batt voltage flutter up/down like mine does?

 

S300 V3

 

So what would a computer connection have to do with it? The tune was loaded on the Ecu; not in the laptop. Do you say that because of the computers ability to make real time changes to the ECU?

 

The connection between computer and ecu is serial. There is no checksum or data verification. It's best effort data delivery. I would say the data is false.

​​​​

 

Yeah it doesn't look like the voltage change is enough to cause a spike like that. So unless there are any other compensation factors that could be getting a bad reading somehow, could be a bad connection somewhere as others mentioned

 

Did this ever happen before you set up flex fuel? That is very strange though. Hope you get it figured out asap.

 

Looks like bad bytes in the data packets, not an actual engine/ecu issue. There's no sign of misfire (lean spikes) or rpm fluctuations associated with the timing spikes, but it's hard to be 100% sure with the slow logging.

is that from an onboard log or recorded direct to the laptop?

 

All my logs are recorded on the laptop, the Ecu does not automatically record logs for me.

so today I did more driving and it's happening in all types of driving from idle, cruise, and wot. If I make a 4th gear wot pull I can feel when it does the spikes

heres a video of my idle this morning and if you listen you can hear some pops or hesitations in the idle as the log displays the spike. so it's does not appear to be a bad computer connection or bad data log.

put on headphones or have computer speakers for this. You need more than just phone speakers

 

I could always hear the pops at idle like is being recorded in the video above, but the ignition spikes never showed up before the Flex Fuel setup. Let me turn it off and see what happens


EDIT: looks like it could be related to the flex fuel sensor &/or the wiring. Soon as I turn off Flex Fuel the ignition spikes seem to stop occurring. I'm on e60 right now so it goes super lean, but the ignition spikes stop. When I turn flex fuel back on the spikes start again.

i had a couple connections that were not soldiered, and I now have those connections soldiered but the ignition spikes continue. So at this point I'm going to build a e60 map so that I can continue to drive the car. I'll make some logs to confirm that I'm not seeing spikes. And I'm going to rework the entire flex fuel wiring.

ill continue to update this thread as I find out more. Thanks everyone i really appreciate the help!

 

Can you show what your flex fuel settings look like?

 

Here's a picture of the settings. Nothing too it really.


As far as I can tell it's most certainly related to something in the Flex Fuel system. Be it the sensor or wiring idk what, I wouldn't think it had anything to do with Hondata though. I made a point to check my ground wire position. Make sure it's bolted to bare metal on the Chassis. That hasn't made any difference.

For now I'm kinda over it. I had planned on targeting a mix of e50 even with the flex fuel setup. I wasn't going to have to be as precise with my mix with the flex (maybe e45-e55) but now I'll just make sure it's close to e50
as I can get it. I've made a e50 tune and that's what it's running on now. Runs killer! This winter when things settle down with the car crowd I'll redo all my wiring from scratch and hope that fixes whatever it could be. Once I do that I'll update the tread. Thx everybody

 

VSS, tps and crank sensors can cause huge timing changes. I had a car come in with a similar issue. Huge timing spikes.. It also had Duty cycle spikes and had some limiters showing active. Well it was the speedo signal dropping out and with the settings it was going in to Antilag driving down the street. This doesn't appear to be your issue tho.

Iv seen bad ignition noise cause little strange hiccups like this.