WOT then lost all boost..

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Hoping for some input/guidance with my 2018 SCREW. Truck has 38000 miles. BMS JB4 and cold air intake. Otherwise stock.

Last week while driving WOT the truck lost all boost. I cant remember hearing much noise when it happened. Definitely not a turbo failure. Seemed like it went in to limp mode, but no warning lights. Got it home and started crawling around looking for a blown off charge pipe.. didn't find one. Disconnected the JB4 and went for a ride, still no boost. Only code was an under-boost code. Cleared that and disconnected batteries for the night. Next day started truck and still no boost. Got underneath with a friend giving it throttle to inspect waste gates, they free and functioning in unison. Turbos are quiet, no bearing noise.

Thought maybe the BOV was bypassing so I ordered a Turbosmart Veeport. Installed that today, still no boost. Truck starts and drives with no CEL, then after a while I get a wrench light. Its gone after restart every time, but there is never any boost at all. I am stumped.

Wondering Plugs/coils? However assuming I would have a misfire code if it was an ignition issue?

Truck has a ticking noise on cold start, but it has had that for as long as I can remember. Once warmed up it all but goes away.

I have Forscan and I've been fumbling with that trying to diagnose however not having any luck. Is there any procedure using Forscan that can help me diagnose what is happening?

Any and all input is very much appreciated!
 

smurfslayer

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1) Have you checked the oil? Low oil or a defective pressure sensor will cause the same symptoms.
2) You had the under boost code almost certainly due to the JB4, and you probably also exceeded a bunch of other sensor values.
3) do you have any current DTC? A wrench light should have DTC’s
 
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1) Have you checked the oil? Low oil or a defective pressure sensor will cause the same symptoms.
2) You had the under boost code almost certainly due to the JB4, and you probably also exceeded a bunch of other sensor values.
3) do you have any current DTC? A wrench light should have DTC’s

The oil level is good, right at the top of hash marks. Not sure how to test pressure sensor?

The only current dtc is P0299 - under boost.
 

smurfslayer

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Do you still have the JB4 connected? If so, disconnect (per the instructions). Clear the DTC via forscan. completely power off the truck then start the truck and re-test.
 

zombiekiller

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check the intake sensor in the tube ( the closest to the air filter). the message that you're getting is for low boost pressure. Either you have a leak in your tubing, or the sensor is bad.

Ive seen the sensor/wires severed, but not all the way on a jb4 setup.

The jb4s are terrible. They arent really so "shockproof" and get their brains scrambled. Once they start to malfunction, they'll blow your motor.
 

FXT

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check the intake sensor in the tube ( the closest to the air filter). the message that you're getting is for low boost pressure. Either you have a leak in your tubing, or the sensor is bad.

Ive seen the sensor/wires severed, but not all the way on a jb4 setup.

The jb4s are terrible. They arent really so "shockproof" and get their brains scrambled. Once they start to malfunction, they'll blow your motor.
good to know
 

Raptor911

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Same thing happened in my Focus RS. Lost power and engine no longer had boost. Looked under the engine and one of IC pipes was disconnected. Reconnected the pipe and had power again. I would check you IC pipes.
 
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Thank you for all the replys!

Do you still have the JB4 connected? If so, disconnect (per the instructions). Clear the DTC via forscan. completely power off the truck then start the truck and re-test.

First thing I did was take the jb4 out of the equation.

Check all connections to inlet tubes and boost tubes? Soapy water usually helps with any boost leaks.

I will go back over all connections. As i said in my original post, I just replaced the BOV. In doing that I had the inter-cooler out of the truck, so all connections are tight down there. Visually everything else looks solid however I will try the soap and water method. I swear I can hear some sort of vacuum back by the firewall, dead center and behind the motor somewhere. Is there anything relevant back there?

i would put my money on boost hose came off. held on with crappy worm gear clamps. replace with T bolts

They are tight at the inter-cooler. Will pull the front tires to get at the turbos charge lines.

check the intake sensor in the tube ( the closest to the air filter). the message that you're getting is for low boost pressure. Either you have a leak in your tubing, or the sensor is bad.

Ive seen the sensor/wires severed, but not all the way on a jb4 setup.

The jb4s are terrible. They arent really so "shockproof" and get their brains scrambled. Once they start to malfunction, they'll blow your motor.

I have a cold air intake installed, I will check that sensor and the mounting location, however not sure how to diagnose if its bad. Wouldn't I see a dtc in forscan pointing to a sensor out of range?

JB4 is removed.

Same thing happened in my Focus RS. Lost power and engine no longer had boost. Looked under the engine and one of IC pipes was disconnected. Reconnected the pipe and had power again. I would check you IC pipes.

Cooler charge pipes are tight. Very frustrating right now without any more codes. I think I'm going to take it for a drive, maybe I can get it to spit out some more data that will be helpful.
 
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