I would see what boost you are running before you get a fuel cut flash, don't want to run 24-25psi and lean out.

 

Ryan...Shoulda, coulda, woulda.

Thanks for the offer Al. I'll try to get the CEL code pulled and a boost gauge installed before the weekend to see what I need to do.

Shiv. when I put the AEM intake on originally, I reattached the stock bov incorrectly. After about 10 miles of driving and with the help of Chris in HB, we realized my silly mistake. But I know for sure that it is correctly oriented right now. I didn't think to check the hoses for leaks in that area. I'll take a look at lunch.

The stumble was occurring at between 3500 and 4500 rpm's each time. I know from previous dyno runs (stock set up) my car spiked at 19psi quickly but briefly in that rpm range.

No cel from my second tank of 91/100 mix.

SC!

 

I have a CEL right now but it is from an aftermarket cat, i.e. 0420. From what I have read though the Evo's seem to throw a code fairly easily. Several stock Evo's with no mods seem to be throwing codes. I have to wonder if this is something that Mitsubishi may actually do something about as it will make inspections very difficult in states that just plug into the OBD II port to pass. I am hoping that the Texas Vishnu dyno day will help when I get the Xede installed so that it leans the A/F out some. In another post it has been said that the CEL will lean out the mixture when it comes on due to a catalyst inefficiency code which may or may not be true. It would kind of make sence as my car will throw a 0420 and after about 60-100 miles will then reset itself and then throw it again in about 60-100 miles. I have to wonder if this could be due to the ECU leaning out the A/F (the other post said a 1 point change) and then the cat can clean up the exhaust to an acceptable range at which time it goes back down one point to unacceptable again and then throws the code. It kind of sounds like a vicious cycle?

https://www.evolutionm.net/forums/sh...&highlight=CEL

here is the other link, read what Gruppe-S posted.

 

SC, i had the same problem with an EVO IV and noticed it was triggered becaused a high-temp inlet air going into the engine.

Findings: Air leaks on I/C and damaged compressor wheel. My boost pressure was 16psi, as usual, then I though my problem was that those 16 psi were reached with really hot air. In my case the I/C resulted almost untouchable (extremenly hot).
Result: i think detonation, knocking problem and, as a result of that, fuel cut at 3500-4000rpm.
Solution: At the same time and during testing & adjusting i replaced inyectors wiring, spark plugs, I/C and O2 sensor. The car felt a lot better but the problem was still present. Finally i replaced turbocharger and the problem has gone.

I´d like to do it all over again (step by step) because this is not the first time i´ve heard of this failure type in latest EVOs. Something is triggering the fuel cut.

 

Well, last night, with the help of Coolguy (Rob) of socalevo.net, we were able to pull the warning. It was the 'random misfire on all cylinders' (0300) warning...or something to that effect.

So I took off to the dealership this morning. They replaced my sparkplugs and reset the ecu. I have not seen the cel since.

But a few days of driving will tell me the whole story.

Thanks all who helped me firgure this out!

SC~

 

My car is doing the same thing! I have a bunch of mods, and can't figure out why the engine seems to shut down at 4000 rpm's. It just stops and you have to let off the gas to keep going...feels like a fuel cut. Did the spark plugs fix the problem?

 

I started having the same problem last night. If feels like your hitting a rev limiter but at 3500 to 4500 rpms. I have buschur stage 1 and 2. Im sure I have everything hooked up right, but the 1g bov does make some wierd noises. I adjusted the safc at that rpm range and gave it alot of fuel and it kept doin it so i dont think its fuel cut. any other ideas as to what the problem could be? Is there a need to advance your timing with all the mods? Im thinkin maybe the bov needs to be adjusted or somethin but I dont see how to do it on the 1g.

 

mine only does it at high boost. If i turn the avcr off and run stock boost levels, i get no cut. It didn't start to do it untill i put the buschur fmic on and instead of running the vacuum line to the bung on the lower intercooler pipe, i t'd off of the vacuum line going to the blow off valve. I also get a lot of vibration on the boost guage, the needle shakes all over....any help?

 

my car is completely stock (3400mi) and it does the same thing.
i took it to the dealer and they said nothing was wrong . i pulled
plug 1 and 4 . 1 was black 4 was brown , any ideas ?

 

It sounds like you guys need to change out your spark plugs. faulty spark plugs will cause bogging/sputtering when hitting boost.

 

my probem didnt start untill after i put in new plugs now that i think about it. The local import shop insisted that I needed new plugs with the horsepower increase from my mods. The guy said they were pre gapped, so i screwed then in hand tight and then about a half turn with the socket. Ill try putting the factory plugs back in to see if it helps the problem. Did I do it right? just screw em but not to tight is what ive always done before.

 

could be your spark plug wires as well.

 

well I changed out the new zex plugs that i had put in and put back in the stock plugs. Still getting the same problem. Noticed its only doin it at high boost so must be fuel cut with the ****ty 91 octane.

 

Nope...changing the spark plugs did not fix things. My cel came back on over the weekend.

SC

 

I am not sure if its the same; However , my evo just started this 14,440 miles, SES lights been coming on and off for the last couple of months, and two days ago it started drop shake like a *****, I was doing 80mph on the freeway and it made some noise started rock/shake felt like( 2nd gear start from a stop) , so down shifted to fourth it pick up, still in foruth freaking out and it did it again, shifted down to third at 65mph, ok for a while, drove home in thrid the rest off the way.
I thought bad gas, Filled up again, Still did it, it does it at of no where, freaks the **** out of me when it happeneds, taking it in today...