Hey folks! I've been a member of this forum since I started searching for my Evo a few months ago. I finally made the purchase a few days ago and I already need some help.

2006 Evo MR, 18K miles. The engine is completely stock (so I was told) and it also appears to be stock.

During the little bit of playing a new Evo owner might do, I am hitting the fuel cut off pretty regularly during heavy acceleration WOT and heavy boost.

I have done some research regarding the safety feature and have a pretty good understanding of why and how it works.

Since my car is stock, the only boost I gauge I have is the stock. I read that a stock Evo 9 should produce a max boost pressure of 20.3 psi at 3500 RPM and fall back to 17 psi at 6500 RPM.

It seems that I can easily peg out the boost gauge to 1.5 bar (21.7 psi) around 4000 RPM and it doesn't seem to drop off any as I approach 6500 RPM. Hitting the fuel cut off scares me and doesn't seem very good for the engine or the transmission when under such a load.

I realize that with ECU tune I can raise load limit but why am I hitting cut off so easily on a stock turbo, stock engine, stock tune?

I've read that colder temps can have affect since it reads from MAF sensor (its 28F here today) but the car did it while I was in San Diego at 60 F as well...

Is there mechanical adjustment to stock turbo or wastegate that gives the car more boost than stock?

Any help is greatly appreciated!

 

is it possible that the previous owner didn't flash the car back to stock if it was modified?

If you're bone stock and with that many miles, why not take it in to the dealer for warranty?

 

Check the sparkplugs!

 

Do a blt

 

Are you hitting the cut in certain gears at certain RPM? Any other patterns you've noticed?

The car could have been tuned, and had the boost raised.

I wouldn't recommend upping the load limits just yet, you've clearly read up on fuel cut and you know it's there for a reason. One thing to look at is the wastegate, might not be performing as it should, I've seen that a lot.

 

I'm sorry I forgot to mention the car has a salvage title so no chance of warranty. It is possible the previous owner didn't flash the car back to stock. As soon as I can get a cable I'll pull the map and see what's in it. Good start...

 

OK I will certainly do this! My brother and I own a motocross/steet bike race and service shop in the midwest. It's coming in the shop tomorrow for oil change. I can't wait to get under the hood and see what makes these things tick...

I am just trying to figure out what to be looking for when I get under there.

With only 16K miles spark plugs weren't the first thing that crossed my mind but its always a simple check!

Thank you!

 

It really doesn't cut out in 1st gear ever... It mostly happens when doing roll-ons to WOT in 2nd, 3rd, 4th gear... and usually around 4-5K or so...

I've really been studying the boost pressure gauge more when experimenting. I'm baffled at how far I can peg the gauge. Tonight I literally saw it go a few good ticks past 1.5 bar which is the max reading on the gauge. The car is pulling EXTREMELY hard when it hits cut off. almost feels like the turbo kicks in twice... regular turbo, then super fierce turbo...then fuel cut and you almost need a 5 point harness to keep from going out the windshield.

I have never driven any other Evo so I don't know what to expect.

So what are things to look for with the wastegate? Is it just mechanically operated with a spring?

Thanks for your help!

 

Just get a walbro 255 and call it a day. That will def will fix your problem.

 

Sounds a lot like an issue I saw on here not long ago. The boost would sit then would shoot up to 30 (over 2.0 bar) or more psi and then fuel cut.

Have a read through this thread: https://www.evolutionm.net/forums/ev...-5-5k-rpm.html - ended up being a wastegate fault (I think).

A wastegate is spring operated, i don't much more about them apart from what they do.

I'm pretty certain your turbo is surging and boosting far too high. I'd recommend not going WOT till you get it fixed, you'll be risking leaning out and doing hard damage to your engine. Fuel cut has stopped your engine from self destructing so far.

If fuel cut is load based, how does a larger fuel pump stop his load limit from being exceeded?

 

Check for a manual boost controller.

 

My car fuel cut at 5000rpm before! I change the spark plugs bam fuel cut gone, there can be lots of things wrong you just gotta go step by step. Good luck with the car

 

[QUOTE=AndyCT9W;9799793]Sounds a lot like an issue I saw on here not long ago. The boost would sit then would shoot up to 30 (over 2.0 bar) or more psi and then fuel cut.

Have a read through this thread: https://www.evolutionm.net/forums/ev...-5-5k-rpm.html - ended up being a wastegate fault (I think).

A wastegate is spring operated, i don't much more about them apart from what they do.

I'm pretty certain your turbo is surging and boosting far too high. I'd recommend not going WOT till you get it fixed, you'll be risking leaning out and doing hard damage to your engine. Fuel cut has stopped your engine from self destructing so far.


Thanks for the link.. I did read through this thread yesterday... he also had some mods and mentioned a backfire... I wasn't sure how relevant his issue was to mine based on the differences. Seems it is a fuel cut issue all in the same... I need to do more research on stock wastegate and boost controller.

Thanks again! You guys are great!

 

Thanks for the link.. I did read through this thread yesterday... he also had some mods and mentioned a backfire... I wasn't sure how relevant his issue was to mine based on the differences. Seems it is a fuel cut issue all in the same... I need to do more research on stock wastegate and boost controller.

Thanks again! You guys are great!

 

What do you mean exactly? Check to see if there is one on the car? Check into getting one for my car?

Thanks for the input!