punctuation hommie, punctuation.

 

Go get tuned dude.

 

This is what I worry about.

 

I'm glad to see I'm not only one who initially thought it sounded like the gap burned out of the plugs. I'm betting dollars to pesos it would be fixed by closing the plug gap a bit.

This.

 

You need to get really F**king mad. I wouldnt even try to fix it because the damage that has been done already will probably cause you problems later.

 

What damage has been done?

 

There's a difference between accepting/enjoying a car that has quirks that make the car what it is vs. genuine problems that are occurring that need to be fixed.
At first I did the same thing.. Every problem that came up I'd be like, oh yea that's okay/normal, or whatever. It's what a lot of buyers do to justify their larger purchases for problems they know they can only accept.
A different mentality plays in when you HAVE to accept something vs. having a choice. And then they come up with every possible scenario in their mind to justify why that problem is actually okay in the end.

I'm sure everyone who ran into the problem without knowing something could be done with an aftermarket tune was like "ooh I like that my car stutters under acceleration, that's unique." I'm sure most would have at least mentioned something to their dealer.

If I bought a 60 in LCD tv and every once in a while the screen went blurry, and all of the other same models did the same thing, I wouldn't say "well that's normal," I'd go get my ****ing money back. No car on the market today should ever require to be tuned in order to function the way it was meant to function.

Also, it's this mentality that facilitates manufacturers to sit on their bums. They see that the general populous does nothing, or justifies it in some manner. Because of the sheer number of complaints about the factory tune, they HAD to do something about it. In similar instance, if everyone says that the increased weight is okay because the s-awc balances it out, why would Mitsu put more R&D into weight savings? Subaru owners had massive complaints/showed by not purchasing the car in 2008, and Subaru immediately made necessary improvements. I would just want my car to have the best, highest quality/reliability

To the OP, I suggest using the lemon law as many have, or just cutting your losses and moving on as I did

 

+1

To the OP: the issue is not detonation, it's misfires. This occurs from the overly rich A/F ratios of the stock tune and is easily fixed by a reflash. I agree that mitsu should put a much better quality tune on these things, but they don't and they wont. There is nothing wrong with your car, and it's not defective. Like this guy said, a reflash will solve many issues and provide many benefits all in one fell swoop, and isn't that expensive. If you can't afford to buy a reflash, then at least pick up a high flow drop in filter like a K&N and that'll lean out the A/F ratios enough to make the car run a bit better in the meantime.

 

Since you don't seem to know much about engine management, I'll give you a quick crash course. Mitsu tunes these things pig rich to keep EGTs low, so as to make the CAT last forever. They also want to ensure an unnecessarily large margin of safety for those who have to run 91 octane because 93 isn't available in their area. This is all fine and dandy, except here's the problem: It's terrible for the engine to run that rich because it can cause fuel dilution issues in the oil, as overly rich A/F ratios allow excess fuel to get past the rings and into the oil supply.

This effectively breaks down the oil and causes the oil to no longer provide proper lubrication properties, which can result in excess wear of the cylinder walls, worn rings, failed rod bearings, etc. It also causes spark plugs to get fouled out from excess carbon build up, only further causing misfires. Because running this rich is terrible for power output, mitsu's pathetic way of trying to make up for this is to run a crap load of timing. The problem with this is that no amount of timing can make up for A/F ratios that are this rich, and it increases the chances of knock. This is why it is fairly common to see datalogs of COMPLETELY STOCK evo 8s, 9s, and especially Xs, with a couple of counts of knock at high rpms.

You want to talk about safety? A tuned X with no knock is safer than a slower, stock X with knock. Now, I don't have time to educate you on all the intricacies of proper engine management techniques, but trust me, you are increasing safety by tuning your car and gaiing stolen power back in the process. If you want to learn more about tuning, you can contact me by PM and I will give you links to threads and articles that are a good place for a beginner to start.

 

...

 

This makes a lot of sense. However a reflash voids the warranty instantly. So the choice is up to you.

 

however the Cobb AP can flash your car and you can then but the origanal map in before taking it to the dealer.

 

Your issue DOES NOT sound like missfire. I know many seem convenced that it is missfire but a couple simple facts lead me more towards det than missfire:
1. Problem gets better or worse depending on which brand gas you use
(This screams det or more correctly knock retard)
2. Problem gets better in colder temps


You need to get on a proper dyno and find out what AFR you are running in stock trim to rule out a fuel supply issue. My VIII had a bad injector from the factory, took forever to figure out but in the end A bright flashlight and looking down the plug holes at the piston tops (3 were black one was just a little tarnished) pointed out that one of the injectors was not working properly.


If it were me I would do the following in this order:
1. run out most of the gas then throw in 5 gallons of 100 octane unleaded.
(if the issue goes away or gets a lot better, your issue is det, proceed with checking the fuel system for supply issues)

2. Change the plugs and check the old ones or have the dealer do it.

3. Get to a dyno and pay for a baseline with AFR and boost plots
(should tell you if anything is ammis with the engine like low power, lean afr, too much boost, etc)

Post up the results and let us think it over some more with added data.

 

Detonation would not feel like a "blip"as the OP describes it. It feels like the car just shut off then started up again a second or so later when the ECU reacts to it and you can usually hear a ping with it. His description sounds more like a misfire to me. I'm betting his plugs are fouled or the gap is burned out.

 

My car has been doing this from the beginning, so could the plugs be fouled from the beginning? The car only had 30 or less miles when i bought it new from the dealer.