When I first bought the car it didnt have any problem getting up to 7k rpm, this was when it had 92 gas with dirty spark plugs that needed to be replaced.

I replaced the spark plugs with new NGK Iridium ones gapped at .024(Same as the old ones that came off of it) and switched over the 92 pump gas over to e85 with the e85 map tune(Car has two different maps for pump gas and e85 according to the previous owner).
*Yes I did try to empty out as much pump as I can prior to filling up with e85*

Now that I switched over maps, the idle is very lean at 17 but the highway cruise is at around 15 which I think its still pretty high according to what most others get on average with 12.

So I decided to try something out and see where my a/f ratio mixture would be at WOT. So I went WOT at 70mph 14 a/f mixture and the car made a loud BANG at 4k rpm in front of the engine and I thought I blew my motor! My foot was still on the throttle when that bang happened but at the same time while my foot was down the throttle cut itself off, it almost felt like a fuel cutoff or when you reach a rev limiter. Luckily I was still able to drive it back home and checked the motor and any leaks and nothing was wrong with the car thankfully.

I have 1000cc injectors and a 255 walboro fuel pimp. I did plan on taking it for a tune but before I do that does it sound like I needed to upgrade the injectors to bigger ones or does this problem sound more like something else? This is my first turbo car and I want to do everything right, any suggestions would be welcoming. Thanks!

 

I don't know much about E85, but from the basics of what I've read on this forum, E85 seems to need more flow than pump gas, so bigger injectors and a bigger fuel pump (I see many installing the Walbro 400lph fuel pump) is apparently a must to run E85.

Either that or the tune is bad.

 

It sounds like your Evo is in limp mode. The previous tuner might have setup a fail safe in the event the ecu saw high knock. There was something wrong and the fail safe activated and put the Evo into limp mode.

Its either that or you could have also developed a major boost leak when you heard the loud bang. Which means that in that event the fail safe could have also activated.

 

Check your intercooler pipes. Sounds like you blew one off. If you're not tuned on speed density the reason your car is running like crap is because your MAF isn't getting an accurate sampling.

 

It sounds like you could have blown off an IC pipe but you would not have made it home if that was the case.

Do a compression check and that will let you know if you screwed it up but good.

 

definitely symptoms of blowing your intercooler piping off, check all piping you most likely have one popped off

 

Thanks for all the help guys! I will check the intercoolers and do a boost leak/compression test, fingers crossed that it cant be anything serious.

 

So let me get this straight, if I did in fact blew one of my intercoolers or any other turbo component, would that cause my car to run lean since it is introducing unmetered extra air into the system?

 

I agree with this. Some sort of fuel cut.

If your ic pipe blew off your car would barely idle, as soon as you try stepping on the gas it would die out. So if you continued to drive all the way home its hard to believe it was a ic pipe blowing off.

 

Im very new to the evo car scene, so today when I checked under my car I panicked and thought one of my intercooler pipes blew off, but apparently it was just an O2 dump whatever the hell that thing does....


I believe my car is in fact in limp mode, because when I go WOT it would shake and the exhaust would hesitate to increase. Sounds like "wwuhuhuhuuhuhuhuhuh" instead of, "wwhhuuuuuuuuuuUUUUU"

Anyway the search continues, I really need to boost leak test the car!

 

Try switching back to your 92 pump map and fuel of course and see if the problem goes away. If it does than its probably your tune.

 

Sounds like you hit the load/boost limit that is setup in the rom, or a wideband failsafe.

An exhaust leak pre-wideband is what is causing your lean idle. Rule of thumb is that a rich idle = vacuum leak, lean idle = exhaust leak. Check and fix exhaust the exhaust leak and test. If there is a wideband failsafe in place and it is a big enough leak, it will trigger on the lean condition.

 

Yes that is exactly what I plan on doing, granted if I could get it fixed somehow before I empty the e85.

Makes sense.. I just found an exhaust leak by the test pipe and the mid pipe. It looked like the previous owner who did it didnt even bother to put a new gasket in there. Ill be stopping by at GrimmSpeed to pick one up soon

 

UPDATE: So I have a Tephra mod ECU, and I unknowingly activated the 'Valet mode' which cuts off fuel at a certain RPM to keep friends/thieves/unwanted people from abusing the car. This feature is what caused my car to get a loud bang at 4k rpm. Makes sense because I did noticed that when I turn the key to the ON position the Service Engine Soon light flashes for 5 seconds before shutting itself off.

Im such a noob, still learning the ins and out of this car. Thank you all for your help!

 

Glad you got this fixed, going to make one more recommendation---that if you ever see your running lean or any other unusual problem-- dont go out and floor it to check anything--ever. You got lucky this time around and happy for you., Too many folks go WOT to "test" something and the engine doesnt make it.. Plenty of examples on this forum.
Good Luck.