I have finally tracked a misfire issue down to IPW dropping to zero during WOT. This happens very quickly then car will regain IPW and continue to accelerate normally. Seems to be load based as the problem doesn't occur under 30psi. I have tried another cam angle sensor but that didn't seen to affect anything. There is a definate trend as it occurs around 14.5-15ms (83-85%dc) and MAf hz around 2800. Load does reach 380-390 around 4500rpm, but problem occurrs around 6.5-7k rpm where load has dropped to 360-370. MAF hz max out around 3100hz @ 8.4k. Boost is around 32psi. If boost is raised to 36psi the event happens about 1k rpm sooner.
Is there anyway this is an ECU based problem? I have the load limit removed, but I'm wondering if I could have overlooked something.

 

You know, I have been running into a similar problem, but I haven't had a chance to log it yet. I just chalked it up to misfire running E85 at 30+ psi on stock ignition in the super cold weather. Maybe I can try to log it sometime soon to see if it's truly a misfire or what you are saying about the IPW.

Just out of curiosity, what ROM are you running. If it's a tephra ROM what is your 1byte load factor set at? I doubt that has anything to do, but just curious if it happens around that value. (I forgot the details on how tephra incorporated the 1byte load into the ROM and if it was only for logging or if it was used in any type of calculations.)

 

Be very careful. This eventually killed #2 rod bearing. My event is very violent and is not the typical gattling gun type of misfire. It's just a single bang.
I'm using 9653006 and the "set to 9" tables for fuel and load limits. If there is some other table I should be using to eliminate this that would be great. I've been chasing this for months now.

 

So, just a normal 96530006 ROM then? OK, I was just curious if it has anything to do with the 1byte loadfactor, which isn't the case if you aren't using the newer tephra versions.

I forgot all about the fuel and load limit (set to 9 values) since the SD patch doesn't need them and I never thought I would need to use them.

I'll still try to dig up my logs, but I think mine truly are misfire. Your issue sounds like some kind of ROM issue though. A posted log would help just to confirm what you are saying as well. It's been a while since I looked at he fuel and load limit tables that jcsbanks posted...are you sure you changed all of them (were there 2 or three?).

Edit: I did have a log of this and my issue isn't the same as yours, so I am pretty sure mine was truly just misfire. My IPW wasn't dropping to 0 as you mentioned.

 

Mrfred has a patch to double the load limit, want to look into that.

 

Might as well ask, since it's the simplest solution and just to make sure you haven't overlooked it.

What do you have your boost limit and timer set at? Maybe you are just hitting fuel cut because of the settings that you have.

The patch the 0xDEAD mentioned addresses that issue (if you still want to keep load limit/fuel cut in place).

 

Sorry I'm using V5.10. Where is 1 byte load factor? My boost limit is still 319 and my BCD timer is 1000ms or whatever stock is. I would love to know that that is all it is. I was under the impression that the "set table to 9" would have removed any limits or "cuts". I'm going to try to increase the BCD timer value and see if that works.

 

Ah...that's your problem then. You have your setting set so that if you are over 319 load for 1 sec, to cut fuel. The load/fuel limit tables that you changed to 0x0009 are just so the ECU can 'see' loads above 380 or so (IIRC) and to keep properly increasing fueling.

Change your timer to something longer than 1000ms. If you want to 'disable' it, set it to like 30000ms (30 seconds). If you want to keep the fuel cut, but want to be able to use higher load numbers, look into the patch that was mentioned.


Eric

 

I assume your on the stock MAS? Look at your MAS Hz once you fix the coding. The MAS Hz should be smooth and non jittery for the whole pull. If Hz is dropping off that is a BAD thing, it means the MAS is missing counts. The fuel cut code will not affect the Hz you should be logging.

1. Fix fuel cut code.
2. Look at your logs and make sure the MAS Hz look good, smooth, and aren't suddenly dropping on you.

 

Bingo. That 0ms injection dead spot is definitely fuel cut. It is quick and violent and just enough to get you to pull that right foot up. Increase the time to be sure.

 

WOW! It pays to stay on top of what is going on in this forum. Increased BCD timer and no more problem. I guess I mis understood what the "set to 9" tables were for. This car has been on E-85 and over 500whp for more than a year and never had fuel cut. Load was always 350ish and never a problem. Problem didn't start until I rebuilt the engine. I had installed the set to 9 tables initially because I knew the larger turbo and CNC'd head on it would definately raise the load values past 380 , and I thought that this would cancel any ECU imposed limits. Inittially I thought it was just a spark blow out issue but after exhausting that road I really thought well now what. This morning I looked at IPWs and saw what was actually happening. I friggin stoked that my car is fixed. Thank you very much for the insight and information posted here. Now I can utilized most of my 45psi boost gauge

 

is this what u guys are talking about? are u seeing this in your logs?

https://www.evolutionm.net/forums/ec...-new-post.html

 

My logs looked very normal other than the injector pulse width would go to zero

 

Did you see this thread?

https://www.evolutionm.net/forums/ec...006-patch.html

 

cool, guess i still for my worries lol..

good luck.