Severe backfire and engine power cut - WOT, full boost @ 5.5k RPM
Thread Starter
Evolving Member
Joined: Mar 2010
Posts: 123
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From: Seattle
Guys I really appreciate all your input and ideas. I was given a biz card by one of the vendors I do business with, he's on here too and highly recommended speedware motor sports in redmond, wa. I may just hand the car to them and have them flash my ecu and fix the fuel mapping/fuel cut issue. No more WOT until this is fixed, at 95k miles, I'm not gonna risk having to rebuild this ***** before it's time.... Engine has never been tuned pre or post cat removal, so I think this is probably my next move.
Thanks again fellahs.
P.s. My avatar was a one in a million shot by a friend of mine during an open track day at PGP in Kent, Wa. I wish I could afford to get out to the track more often, but my playground is the streets and highways of the emerald city.
Thanks again fellahs.
P.s. My avatar was a one in a million shot by a friend of mine during an open track day at PGP in Kent, Wa. I wish I could afford to get out to the track more often, but my playground is the streets and highways of the emerald city.
Thread Starter
Evolving Member
Joined: Mar 2010
Posts: 123
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From: Seattle
If it's a fairly violent cut, like you nearly lose a tooth on the steering wheel, it's likely to be fuel cut. (Possibly the same thing as boost cut, I keep reading different things on boost cut).
The definition for fuel cut is that your load is exceeding a certain amount for more than a certain amount of time. Load is relative to boost, so basically your boost is too high for too long. The time is a matter of seconds. I don't know the amount of boost that triggers fuel cut in a factory ROM. My IX fuel cuts at 23 psi, but it has been tuned.
Boosting 30 psi is a bit much. If you don't have a boost controller it sounds like your wastegate isn't doing it's job, faulty or not being controlled properly.
Adjusting the fuel cut is fine if it's done someone who knows what they're doing. It is possible to delete fuel cut but I would never recommend that, it's like taking away your brakes cause you don't plan on slowing down.
Personally I would look into why your boost is going that high before looking at changing your fuel cut.
The definition for fuel cut is that your load is exceeding a certain amount for more than a certain amount of time. Load is relative to boost, so basically your boost is too high for too long. The time is a matter of seconds. I don't know the amount of boost that triggers fuel cut in a factory ROM. My IX fuel cuts at 23 psi, but it has been tuned.
Boosting 30 psi is a bit much. If you don't have a boost controller it sounds like your wastegate isn't doing it's job, faulty or not being controlled properly.
Adjusting the fuel cut is fine if it's done someone who knows what they're doing. It is possible to delete fuel cut but I would never recommend that, it's like taking away your brakes cause you don't plan on slowing down.
Personally I would look into why your boost is going that high before looking at changing your fuel cut.
Evolved Member
Joined: May 2011
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From: New Zealand
I haven't heard of removing the cat causing over boosting, but it would make sense. If putting the cat on stops your over boosting, then I'd recommend getting a manual boost controller and an ECU tune by a good tuner. Then you can can run with no cat and get more HP quite safely.
Thread Starter
Evolving Member
Joined: Mar 2010
Posts: 123
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From: Seattle
I haven't heard of removing the cat causing over boosting, but it would make sense. If putting the cat on stops your over boosting, then I'd recommend getting a manual boost controller and an ECU tune by a good tuner. Then you can can run with no cat and get more HP quite safely.
Thread Starter
Evolving Member
Joined: Mar 2010
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From: Seattle
UPDATE*
So, under PENDING codes I find today a P0234 stored in reference to wastegate system fault...figures. Smoke test reveals no vacuum leaks other than the mitsubishi standard throttle spring seal.
Scanner says could be an actuator, charging system pressure control system fault, or the ECM itself. Will spend time on monday continuing the diagnosis. Thanks again.
So, under PENDING codes I find today a P0234 stored in reference to wastegate system fault...figures. Smoke test reveals no vacuum leaks other than the mitsubishi standard throttle spring seal.
Scanner says could be an actuator, charging system pressure control system fault, or the ECM itself. Will spend time on monday continuing the diagnosis. Thanks again.
Good luck man. While installing the new solenoid, make sure the "pills" (restrictors) in the solenoid/actuator vacume lines aren't clogged shut either. They *will be harder to blow through than a straight vacume line. Do a search to see which ones have them/or someone chime in.
Reference:
https://www.evolutionm.net/forums/ev...-solenoid.html
Post #2 Attachment.
Last edited by evoredy; Nov 8, 2011 at 04:08 PM.
Thread Starter
Evolving Member
Joined: Mar 2010
Posts: 123
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From: Seattle
No. There's a short line coming out of the wategate actuator. That definitely has a pill in it. Actually, it is THE pill that most modify (restrict more) to allow ECU based boost control to higher the maximum allowable boost cap at the physical level. The restriction really needs to be pretty tight when using stock springed/stock preloaded wastegate actuators. Probably not an issue for you, but it's good to know all about the factory boost control system when you have issues like stated above.
Reference:
https://www.evolutionm.net/forums/ev...-solenoid.html
Post #2 Attachment.
Reference:
https://www.evolutionm.net/forums/ev...-solenoid.html
Post #2 Attachment.
Thread Starter
Evolving Member
Joined: Mar 2010
Posts: 123
Likes: 0
From: Seattle
No. There's a short line coming out of the wategate actuator. That definitely has a pill in it. Actually, it is THE pill that most modify (restrict more) to allow ECU based boost control to higher the maximum allowable boost cap at the physical level. The restriction really needs to be pretty tight when using stock springed/stock preloaded wastegate actuators. Probably not an issue for you, but it's good to know all about the factory boost control system when you have issues like stated above.
Reference:
https://www.evolutionm.net/forums/ev...-solenoid.html
Post #2 Attachment.
Reference:
https://www.evolutionm.net/forums/ev...-solenoid.html
Post #2 Attachment.
Sounds like your wastegate didnt do it's job like it was supose to and boost spiked, rev limit hits and fuel cut saves your motor. Your running 24psi now? Are you tuned? Do you have an wideband to watch ur AFR?