ECUflash Excessive knock and crazy backfire

[jdm9221]

I was doing a test pull on a new tune, 1st gear pulled super hard as did 2nd but during 2nd gear the car backfired hard and I let off. It felt like when you blow off an intercooler pipe but it's definitely not that because it did the same thing last pull. This time I logged it on evoscan and my timing seems to go weird and I got 7 counts of knock! What could be causing this? I do have the full evoscan log I can post if you're interested in helping but I'm on my phone rn. In the picture left to right its throttle position,rpm,knock and timing advance

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[19gsx91]

I'm not familiar with evoscan but something doesn't look right to me.. at the cell where you're 5031.25rpm you have 0 knock but 3degrees of timing.. then at the very next cell you have 7 degrees of knock but 12 degrees of timing.. What does your table look like to have that big of a gap?

 

[jdm9221]

I'm new to the whole thing and had someone else setup the tune. After glancing over my evoscan log I definitely knew something was wrong so I hit the forums for a hopeful answer. The car was pulling hard and went from 0 to 7 counts of knock in an instant and I definitely need help figuring out why

 

[19gsx91]

Can you post a picture of your timing table? Something doesn't seem right with those timing numbers

 

[jdm9221]

Timing table in ecu flash or the timing table of the evoscan log?

 

[19gsx91]

the whole timing table in ecuflash, just post a screenshot like you did the first picture.

 

[jdm9221]

If I had any idea how to pull it up I wouldi have absolutely no clue how to make adjustments or even open the rom on ecuflash. I can send you the rom on the ecu rn and you can open it and check it out if you'd like?

 

[jdm9221]

So the timing map is the stock evo 8 map which is very close to the DSM map. Something caused it to advance

 

[jdm9221]

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[jdm9221]

so after looking at it when it popped the DSM timing map would be advancing 13 and the evo was only advancing 2. Could that be my whole problem?

 

[Vegas Smith]

Other things to look out for are low oil, bad rod bearings and improper position of knock sensor.

 

[jdm9221]

Oil levels good, I would have more problems if I had a bad rod bearing. How could the knock sensor be improper? There's one spot and it's torqued at 17 ft lbs

 

[19gsx91]

Yeah, the timing maps look fine, but something still seems goofy with that jump in timing to me

 

[Vegas Smith]

There are about 3 spots people can accidentally put it on the block. You may not know you have bad rod bearings yet. I'm not saying this is the case but something to think about.

 

[jdm9221]

I pulled the old knock sensor out and put the new one right back in

 

[jdm9221]

I'll consider it a possibility but I would assume I'd have a lot more signs of a bad rod bearing

 

[SOADweskey]

Yeah, the timing maps look fine, but something still seems goofy with that jump in timing to me

I'm with 19gsx91 on this, do you have a log of Engine Load % at the same time. Something made your timing jump 9 degrees very quickly. from those table it looks like at 5031 RPM your ecu thought it was at about 250% load and then by 5656 RPM the load had suddenly dropped to 180%.

I'm not familiar with evoscan at all but load should be calculated by cylinder pressure, which comes from airflow per rev.

 

[jdm9221]

I can log another pull while logging load but I don't wanna hurt the car for sure. Lmk if you want another one because I wasn't logging load at the time

 

[SOADweskey]

Well, I'm not a professional tuner by any stretch. If you are worried about the car then don't do it.

 

[Vegas Smith]

I'll consider it a possibility but I would assume I'd have a lot more signs of a bad rod bearing

1) Just because you replaced the knock sensor in the same location does not mean it was ever in the correct location in the first place. You wouldn't be the only person to ever have that happen.

2) You may not have any signs yet of bad rod bearings. There was a guy on the ecmlink forums just last month who was getting a bunch of knock and it turned out it was bad rod bearings causing the knock......and he had no idea they were bad.

3) If you don't have a log of this happening then there isn't much information to go off of.

 

[95REGF150]

The bigger problem too me would be how the log picked up a 500 rpm drop when he was at full throttle the entire time. He had a hiccup in some way for the engine too drop speed like that in the middle of a pull. And it was before the knock was registered. This points too a mechanical or electrical issue either with the engine itself or the sensors. But I would agree with the others above. If you do not even feel comfortable opening the ROM in ecuflash then you have no place attempting too make adjustments. Find someone who can troubleshoot this for you looking at the car so you dont blow it up. The forums can only go so far too help you as we cant see the whole picture.

 

[99ECLIPSEGSXDSM]

What plugs and gap are you running? I had this problem for about a year before I tired a tighter gap than suggested and if worked for me

 

[jdm9221]

Copper plugs at .22 Never stated any intentions of trying to change the tune myself. I've already been looking for someone to tune the car

 

[Tiki2777]

There's a big can of worms to open here, and your option is to have your tuner fix your problem (barring any possible mechanical issues) because he "tuned" it.

Or..... because it's really not that hard, learn to tune the parameters yourself, and start from modifying the original unedited stock maps. Of course only you can know if your knock sensor is in the right place...there's no odd electrical gremlins...etc.

Ceddy.us and the 98/99 flash tuning pages is where you need to go for doing this on your own

 

[kanusky1990]

Do you have any means of posting the tune that is currently in the car for others to look at for you? Perhaps you can get your tuner to email it to you?

If not, one thing that comes to mind is there are two separate timing maps in the ECU. A high octane timing map and a low octane timing map. Ideally you want the car to only use the HIGH OCTANE maps, as they are used when no knock is present. They are meant to be the upper limit of how aggressive your tune is. The LOW OCTANE maps are used once knock is logged. The tuner "should" have set the LOW OCTANE tables to be more conservative (ie, less timing) EVERYWHERE across the map.

If timing changes were only made to the High octane map, there could possibly be areas where the LOW map is actually more aggressive than the HIGH map. Once knock is registered, the ECU now looks at the LOW map, which might be telling it 14 degrees versus the 0 from the the HIGH, making the problem WAY worse.

If the tuner won't send you the ROM, and does not help with the problem, I suggest looking for a new tuner.