I have a RCSB tundra with the 5.7. I am running a master power turbo and tuning with a Unichip. I have had the system for about 9 months and 8k miles. Recently it has started doing something crazy and I cant figure it out. Under any type of boost, it pulls hard and then about 4k rpms it just shuts the throttle body. It maintains the rpm until I let off the gas. I know it closes the blade because it will build vacuum back to -13 on my boost gauge. I have cleared the pcm memory. unpluged the steering angle sensor and nothing has helped. I have No codes in the system and no lights on the dash. When this happens, no traction lights flash. I am at my wits end. Any advice???
Boost problems with 5.7
- Thread starter TURBO5.7
- Start date
The 1UZFE EGR Delete Kit is available for sale here.
I wouldn't think knock would cause the ECU to shut the TB? Normally when knock is detected, the ECU pulls timing.
The whole point is to quickly reduce load on the engine, so I suppose it's possible with DBW, but pulling timing has always been the accepted way. (perhaps I'm just showing my ignorance of contemporary DBW systems
)
The whole point is to quickly reduce load on the engine, so I suppose it's possible with DBW, but pulling timing has always been the accepted way. (perhaps I'm just showing my ignorance of contemporary DBW systems
)
spf_lexus
Active Member
I know the DBW has a stepper motor that requires a decent amount of voltage. If there is a cut in voltage the blade closes. I swapped a VVT engine a while back and realized my aftermarket ECU did not have a high enough output to power the DBW motor. Is there any way that the voltage feed to the TB is getting high resistance from your turbo's heat? When you dropped the boost, maybe the heat dropped along with it? Just an idea.
Its a remote mount turbo set up. The highest I've seen the intake air temp is 117 degrees. At lunch with no boost it was doing the same thing. It seems to be getting worse. What would be normal grams per second to flow through the MAF. Any other ideas.... Its got to be a bad sensor, right?
stevechumo
Active Member
Try to disconnect the air intake pipe from the turbo to the TB, so no air from the turbo is fed to the engine. The truck now drives like normal before. Then drive it hard to red line to see if the TB is shut down. After this, then we can move on to other areas.
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