Good day all,

On the 28th of March, I went for a drive and during the drive after trying to pull off on the main road my vehicle just stalled out and shut off. All the lights were still on but the vehicle was off. I pulled off on the side of the road and started it back up, it cranked up and did its normal thing where the gauges would go up and down and just died out again. This basically came out of nowhere but I tried to crank it a few more times and had the same issue. I first thought it was the battery but the fact that I could crank and start the car up several times before it died shows me that the battery seems to be just fine. I then thought it was the alternator for the car but I really had no way of knowing. About a half-hour later the battery died from me trying to start the car, I remember I had a jump pack in my car another 10 mins later. I popped the hood started it up and it stayed on and I hurried back home. When I got home I left the vehicle on and I did the old school method of change the alternator by removing the terminals and seeing if the car would turn off (not sure if this practice is still recommended.) afterward I got my multimeter to test the voltage and I was getting a good 13.9 which I'm assuming is normal and monitored it for a few.

I left the car for a few days and came back to check and notice that this hose was disconnected in the picture below.



I don't know how it got disconnected I don't know if some work was done on the car a long time ago before I bought it and the clamp was never set back in position because I never had any issues with the vehicle since I had it but I did try to wipe some dust off the engine like about a week before the problem maybe I knocked that hose off without knowing (yes I know the engine is very dusty, I live on a dirt road, unfortunately.

So do you guys think the hose was the cause of the car shutting off? I drove it yesterday and it doesn't seem like it's having any issues that I should worry about but I don't want to be driving when its rush hour and get stuck in the middle of the road holding up traffic.

Yesterday's trip I used a Bluetooth ODB tool to monitor the battery level while driving to see if it could be the alternator having an issue and went to the gym and the barbershop, both times the voltage was at 13.9v on average. I then decided to drive to my girlfriend's house and once again it was at 13.9 on average but on the way back home it was at 13.0V average all the way back home.

I believe that hose is from the brake booster or maybe PCV system to the intake. Basically, it keeps vacuum where there needs to be vacuum by having the car continually sucking air while on. It is pretty important and could cause issues by being disconnected like that. A possible issue of a vacuum leak is stalling.
Another issue with the hose like that is you are sucking non-filtered air into your engine and living on a dirt road that could be some bad news.


Your car dying doesnt sound exactly battery-related to me if it cranks just fine when trying to restart and voltage checked out good.

EniGmA1987 wrote: ↑

Tue Apr 13, 2021 10:09 am

I believe that hose is from the brake booster or maybe PCV system to the intake. Basically, it keeps vacuum where there needs to be vacuum by having the car continually sucking air while on. It is pretty important and could cause issues by being disconnected like that. A possible issue of a vacuum leak is stalling.
Another issue with the hose like that is you are sucking non-filtered air into your engine and living on a dirt road that could be some bad news.


Your car dying doesnt sound exactly battery-related to me if it cranks just fine when trying to restart and voltage checked out good.

Ok well hopefully that was the issue, at first I was thinking the hose was for the mass airflow sensor.

biglo wrote: ↑

Tue Apr 13, 2021 10:21 am

Ok well hopefully that was the issue, at first I was thinking the hose was for the mass airflow sensor.

That sensor is farther forward in the intake. Basically what is going on with that hose being off is you are defeating the sensor by bypassing it with some of the engine airflow. This causes much more air to be in the engine than the computer for the car thinks there is. Quite possibly thinking you are at idle air even when much faster. Obviously, this can cause some issues.

EniGmA1987 wrote: ↑

Tue Apr 13, 2021 10:24 am

biglo wrote: ↑

Tue Apr 13, 2021 10:21 am

Ok well hopefully that was the issue, at first I was thinking the hose was for the mass airflow sensor.

That sensor is farther forward in the intake. Basically what is going on with that hose being off is you are defeating the sensor by bypassing it with some of the engine airflow. This causes much more air to be in the engine than the computer for the car thinks there is. Quite possibly thinking you are at idle air even when much faster. Obviously, this can cause some issues.

I meant to say throttle body lol sorry, but thank you for your response. I'm gonna drive my car tomorrow and see how it goes. So far it feels good as new from yesterday. Already shelled out 220 bucks on a battery that I didn't even need.

biglo wrote: ↑

Tue Apr 13, 2021 10:26 am

I meant to say throttle body lol sorry, but thank you for your response. I'm gonna drive my car tomorrow and see how it goes. So far it feels good as new from yesterday. Already shelled out 220 bucks on a battery that I didn't even need.

Yah, I don't know enough about the Fuga to say for sure, but I think Enigma's guess of a PCV breather hose is right. If the other end goes to a valve cover, that will confirm it. With all the visible dirt, if the hose was off for awhile, there's a good chance a lot of that crud ended up in the PCV plumbing. That's to say, inside the valve covers. So you might want to get the engine flushed out.

VStar650CL wrote: ↑

Tue Apr 13, 2021 1:54 pm

biglo wrote: ↑

Tue Apr 13, 2021 10:26 am

I meant to say throttle body lol sorry, but thank you for your response. I'm gonna drive my car tomorrow and see how it goes. So far it feels good as new from yesterday. Already shelled out 220 bucks on a battery that I didn't even need.

Yah, I don't know enough about the Fuga to say for sure, but I think Enigma's guess of a PCV breather hose is right. If the other end goes to a valve cover, that will confirm it. With all the visible dirt, if the hose was off for a while, there's a good chance a lot of that crud ended up in the PCV plumbing. That's to say, inside the valve covers. So you might want to get the engine flushed out.

Personally, making a quick guess I do remember wiping down some of the dust of the top of the engine and maybe it was around that time where I knocked the hose off without noticing. If that is what happened I would say the hose was off for about on the 20th of March which was when I changed the oil on the vehicle. So I'm starting to think I may have knocked that hose off when I was wiping it down and maybe it came loose easily because the clamp was never on correctly. But you may still be right. Better safe than sorry.