As far as I know the only advantage of sequential injection is smoother idle and lower emissions. Most HP cars switch to grouped injection when it all starts happening but that doesn't solve the problem here. Usually to melt pistons so violently it's quiet obvious eg timing or fuel so best put the thinking caps back on. I haven't had much to do with E85 as the cars here using it are flex fuel and it really wont matter what mix you have. The racers buy in 200L drums to be sure. Not from the pump.

 

A lot of considerations in this thread.. One thing, if all other have proven to be good, you are running and aftermarket IM. You have detonation, melted the same piston on two occasions, have checked the mixture of the fuel, injectors and the control box--Several have pointed at excessive knock in your logs, I assume you have either rejected that or fixed it. The intake and head porting both effect fuel distribution which in effect can cause one cylinder to go exceptionally lean and could easily show a good mixture when tuning. Just a thought. A poorly ported stock manifold can cause the same thing. Not a condemnation if anyone's manifold, mistakes can be made. Good luck.

 

Has anyone ever documented cylinders running more lean than others because of an intake manifold? I am running an AMS VSR which is a proven part on many cars with no known failures. I have considered this may be the issue however this is a pressurized system, at any given time the manifold pressure is equal to all four runners how could it be forcing more air into the number 1?

On that note I am having the head tested on a flow bench to see how it is flowing between the cylinders.

 

wow, finally got around to viewing these logs....pretty much says it all.

why the issue was rectified after the 1st pull, is beyond me.

your coolant temps are ~18f higher than they should be before the pull is even started.....

find another tuner.... if it's you, have someone else tune your car.

why isnt your accel fuel sorted as well? just because you see reasonable afr's @ 5500 & peak boost, your afr's are really being muddied by the accel fueling that is going berserk.

 

I do not have a lot of tuning knowledge only the basics and learning as I go. I had a professional tuner dyno tune the car both times it melted down. What do you mean by sorting the accel fuel? Is this a setting or something in the tune that is not done right or not setup properly causing it to melt down even though it looks safe?

 

I see 3 differrent potential problems that all can lead to your failures.

1. detonation
2. running hot, pistons expand & bite the cylinder walls, even worse with detonation.
3. accel fueling being applied during WOT (wrong), which will add fuel when in reality it shouldnt be added, causing lean conditions when accel fueling is stopped, the sudden / random lean conditions will not be picked up in a data log, especially within a wideband sensor who knows how far away from the piston/combustion chamber!

This is only noted with a handful of useful channels being logged within internal log file.

on top of that, the air temp is already fairly warm @ 100f / 39c, who knows if your tuner even has ign trims applied for airtemps...my guess is not, because the ign map is still rising during the pull, as temps are increasing.

 

Hmmm...we may be getting somewhere now, would the accel fueling during WOT be something the tuner had to setup?

Also just for information my wideband sensor is located in the post cat o2 bung.

 

Here is an update from AEM for my EMS, perhaps this contributed to the failure:
"Inspection found unit to need mods. All mods updated and unit is fully functional. Passes all tests on bench."
"All of our EMS units start off with a specific MOD and Revision setting A and A. Though long term usage and diferent configurations, we sometimes find limitations and such that would cause the unit to either function poorly, not as intended or simply fail. The fixes to the internal board are labeled as MODs and Revisions. As we make more changes, the lettering goes up in the alphabets. Your unit was missing mods to bring up to current standards and that is what was done."

 

Since you are in Colorado, why not take your car to Jacks Transmission and have them sort you out. Sometimes you just have to admit that the problem is beyond your ability to fix.

 

I have already talked with Jack's about building the motor and going through everything for me. They informed me they will only build the motors listed on their website and will not overhaul other setups.

 

I may have missed it but can you take a picture of the rod bearings and the mains?

 

Seems at odds with whats listed on their website
"13) We are very flexible and can usually build an engine in any way you want using any parts you prefer. Some parts are just not good enough, so please let us know what you had in mind and we will give our honest opinion."

Why not ask them to just to a rebuild with the parts you have. If something needs to be replaced they will tell you.