Hey so I have a 05 evo 8 mr with a 9 turbo, and few mods. Nothing crazy. I had it for about 2 years now and it’s my daily and I baby it.(of course I have drove it for the fun sometimes but barely, I only launched it once).....anyways about 5-6months ago it started to stutter/buck while I’m on the gas driving normally, it was like if the turbo stopped for a sec or something and it did it like maybe once every 1-2months. I thought the first time it did it because of bad gas(I really needed gas and there was no good stations around but still put 91) and it stopped after I put different gas but when it did it again like a month or two after I thought it was because I didn’t have the coil packs so I got a spoolin up kit and it was good for another 2 months before it happened again. So I took it to RRE(it happened again while I was headed there) and went test driving with them and it behaved perfectly fine, tried WOT from low and high rpm, stop and go normally, stop and floor it, half throttle, whatever way we can think of that will repeat that problem so they can diagnose and fix it(also fix something else really quick not related) I left it with them for about 3 weeks to test and check everything out,he said it did it once again when they were testing it but nothing seemed to show what would cause it.( also checked internals and compression test and everything) I got it back about almost 2 weeks ago and it happened again this morning on my way to work and when I was on my way back I was able to repeat it, every time it would start to build boost and hit 0 bar, it would stop/buck/stutter and would not go past 0 bar. It will drive if I stay out of boost but once it starts is when the cars would do that. If anybody knows/been thru/ or have any info about it, please let me know. Thanks again

 

Hey Danny @Danny Oh , Welcome aboard

Im sure RRE pulled the ECU logs & reviewed them?

Are you tuned for E85 as well?

Did they tune the EvO while it was there for 3 weeks?

Joe

 

No I don’t think they did that, and yes I am but I haven’t used e85 since I got the car because I don’t have any stations around. It was safe tuned when it had a head job done before so the head can break in. I wanted to retune it if the issue was a small boost leak or something but it’s working fine when they were test driving it and when I was in the car with them.we both agreed we need to find this issue first before tuning it lol I also asked them to replace my slave cylinder while it was there

 

Is it on speed density?

 

Don’t think so, if my understanding is correct it’s the normal mass air, we thought maybe the one on the intake filter was going bad but he said if that is bad, it wouldn’t be on and off, it’ll be consistent.....so I drove it again this morning when cold & hot and it’s doing it consistently now....I also tried to rev it while in N( pretty much tried the launch control without launching) and it would not even go up to 5k rpm, it stops like at 3.5-4K and doesn’t go higher and the boost stops/cannot built up. To be exact all my mods are ported cylinder, apr valves/studs/springs, 280 cams, injectors + pump, dual map safe tune to built in the head , nesei intercooler, 9 turbo, and couple bolt ons like exhaust,dp & intake. I talked to rob over at RRE again to explain it a bit better because it’s more consistent over the past 2 days and he said it might be lack of fuel or dirty fuel filter or a busted o ring around the fuel pump.

 

Does it have an AFR gauge? If so, what does it read when it won't rev?

I agree that it could be the fuel pump, or fuel system related.

 

No only the factory battery,coolant, and boost gauge, I should probably get some gauges to read other stuff lol
And yea right now I’m just trying to check it out on my way to/back from work because it’s only a few blocks so i wont get stranded. And also so i can see how consistent it gets...so I can help RRE diagnose this issue because it ran perfectly fine as soon as it was ready to see the doctor lol idk why cars magically fix themselves when you take it to the shop smh lol
i was also starting to think maybe the turbo was going out but when I felt how well and powerful it responded while we were test driving at the shop, that doesn’t seem to be the case....boost maxes out the factory gauge at 1.5bars and stays in there from around 3.5k-til redline...so yea turbo seems to be fine lol