Boost Issues
Thread Starter
|
Tuned
Joined: Oct 2015
Posts: 388
Likes: 84
From: Roebuck, SC
Boost Issues
Hi All. I haven't posted in a while, truck has been doing good recently.
Now, boost issues are cropping up.
I had noticed that randomly, boost would just disappear, then come back by itself. Running a stock tune.
I put EBP, MAP, BARO, BOOST and VGT on my edge CTS to see what was happening.
EBP looks normal and responds with the throttle as you would expect.
BARO is consistent, 14.3 in my area.
VGT responds normally, as long as I have MAP
MAP is the one that, at first, appeared to be the issue. It would read normally, then go to atmospheric and not budge. When that happens, VGT goes to 15% and won't budge.
I put a new MAP sensor on it, cleaned out the orifice on the intake manifold, confirmed the hose was clear and electrical connection was solid, then BOOST got worse. Now it rarely boosts as it should.
One other symptom to think about, not sure it's related:
When the truck is cold, 80-90 ECT, on acceleration MAP will go to around 30, BOOST to around 22, but absolutely no power. How could I possibly have that much boost but the truck feels like it is bogging down, about to stop running? I also get big time turbo fart when I let off the accelerator under those conditions.
I do have P0470 most of the time, even though the EBP value does display on the scanner.
When no boost appears I get P0069 MAP Baro correlation.
I also get P0299 underboost when the MAP doesn't read and the VGT goes to 15%.
Possible causes?:
Wiring/harness issues?
Bad new MAP sensor?
Turbo bad? (not spinning?)
VGT actuator issues?
Cat stopped up?
Anyway, any insight is appreciated. I am going to start digging into it now. The way my job is I don't have much time during the week to actually work on anything. Work, eat, sleep, repeat.
Now, boost issues are cropping up.
I had noticed that randomly, boost would just disappear, then come back by itself. Running a stock tune.
I put EBP, MAP, BARO, BOOST and VGT on my edge CTS to see what was happening.
EBP looks normal and responds with the throttle as you would expect.
BARO is consistent, 14.3 in my area.
VGT responds normally, as long as I have MAP
MAP is the one that, at first, appeared to be the issue. It would read normally, then go to atmospheric and not budge. When that happens, VGT goes to 15% and won't budge.
I put a new MAP sensor on it, cleaned out the orifice on the intake manifold, confirmed the hose was clear and electrical connection was solid, then BOOST got worse. Now it rarely boosts as it should.
One other symptom to think about, not sure it's related:
When the truck is cold, 80-90 ECT, on acceleration MAP will go to around 30, BOOST to around 22, but absolutely no power. How could I possibly have that much boost but the truck feels like it is bogging down, about to stop running? I also get big time turbo fart when I let off the accelerator under those conditions.
I do have P0470 most of the time, even though the EBP value does display on the scanner.
When no boost appears I get P0069 MAP Baro correlation.
I also get P0299 underboost when the MAP doesn't read and the VGT goes to 15%.
Possible causes?:
Wiring/harness issues?
Bad new MAP sensor?
Turbo bad? (not spinning?)
VGT actuator issues?
Cat stopped up?
Anyway, any insight is appreciated. I am going to start digging into it now. The way my job is I don't have much time during the week to actually work on anything. Work, eat, sleep, repeat.
Thread Starter
|
Tuned
Joined: Oct 2015
Posts: 388
Likes: 84
From: Roebuck, SC
Thanks xcrsp440, I appreciate your input.
I cleaned the EBP sensor, sensor mount, tube and maniifold fitting.
The tube and fitting seemed ok, they were clear.
There was some buildup in the 45 deg mount and I think it was stopping the sensor from reading correctly.
All is good and it is boosting normally now.
Jim
I cleaned the EBP sensor, sensor mount, tube and maniifold fitting.
The tube and fitting seemed ok, they were clear.
There was some buildup in the 45 deg mount and I think it was stopping the sensor from reading correctly.
All is good and it is boosting normally now.
Jim
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