What happened:

Just cruising at 65mph then I feel a lost of pickup and it slows down.
When I pull off it will only idle.

when ever i pickup the throttle it seems to die out, then I sort out what and why: it seems to die out whenever I come off manifold vacuum.

I tried to slowly pick up the rpms and it will but as soon as you get into
any boost it dies out almost like a fuel cut out and it is only when you hear the BOV build.

I tried disconnect the battery and bead of the juice to do a ecu reset to help then tried all other maps no difference.

I did not see any build up of black smoke from the exhaust no cels shown.

So after some time I took off the coged blower belt and I was able to get home.

05 g35 vortex 303 pulley and Osiris tuned

Has ran perfect for over 6k..

Thanks for any help
Marty

 

by "come off manifold vacuum" do you mean when you go into boost?

if so then DO NOT BOOST THE ENGINE. Something has changed or went wrong. Take it to a mechanic to get it looked at before the engine blows up. Not a wise idea to keep trying to push it into boost if it keeps stalling when you go into boost.

 

Thanks but it did not matter if I pushed into boost just any time I cracked the throttle
and lost manifold vacuum I am sure it is a sensor or my MAF.

Something in that area it did not go rich or lean as far as i could tell and temp never changed.

Strange

 

I should say not stall but loose power if I kept the throttle open the yes it would die but let the vacuum pick back up and it would stay there.

 

Well I am still stumped, and no answers yet

I removed the coged belt and it ran OK
got up this morning with the motor cool and re installed the belt and it
started up but not normally, like it was loaded up and took throttle OK
but a slight lag from low RPM all of this in park. no load and with cold motor
so the cold idle circuit is on.

once It warmed up it went back to the same issues.

I re-flashed the ecu and still the same (hard start and falls on its face as soon as you crack the throttle and I see the vacuum drop) but if I slowly pick up the RPM it will go,I can hold it at 3k But if I tap the throttle it will fall and if I keep the throttle there it will just die but if I just lift it will idle.

Still no cels.

I then removed the belt again and it seems to have the same issues


Please help.... I am not a noob have plenty of experience on racing motors and mechanics just when it comes to all the electronic controls our VQs have shooting in the dark is no fun and I hope someone else has had the same issues and can help..

Thanks again..

 

do you have a data logger? check and see if injectors are still operating Propperly. Faulty coil pack? bad plugs?
I would lean towards something fuel/ignition. because if your losing when you get close to boost is when you afr gets rich, maybe not enough fire?... I think that would be my starting point

 

BOV or BPV?

You should have the BPV on the passenger side. Normally open and closes with the buildup of boost in the manifold.

Sounds almost like a post maf leak, like you popped off a coupler/pipe between the maf tube and TB.

 

Nah, even so it shouldn't be dying. it would still rev up and drive normal to an extent just with the mani in vacuum instead o building boost

 

Thanks for the help but checked all pipes and all fine.
It is the blow off valve and when the manifold vacuum pressure
drops it will close the valve to build boost. so when ever it closes
it dies out..

even at idle when I see the boost-Vacuum gauge drop vacuum it wants to die out but if I very slowly pick up the RPMs it will not stall out.

I even removed the blower belt and still it seems to be the same..

I will remove the MAF and throttle body and carefully clean.
will post later as it is a pia to remove the tower bar to get at..

Thanks again

 

So you have a BPV and a BOV?
Stock vortech comes with a BPV.

Is your filter clean?

 

OK stock valve BPV and filter seems clean still looks red..

What makes me feel it is a Something else is when I was stranded yesterday
I pulled the coged belt off and drove back home 22 miles and after a few miles it seemed to drive OK.

I was able pull though the gears fine but did not push past 5k and seemed fine so I do not think it was a filter clogged but it could be the MAF or throttle body dirty.

If not it should be a sensor fail

Off to Canada Day festivity's and leave the G,s stress behind today....

I get to enjoy me 4th of July next week as well!

 

look into your ambient temperature sensor or whatever.. The one that sits in from of the radiator, two wire connector. Sometimes if that goes wonky your care won't run worth a **** too. I thought i had a dirty MAF and it was that sensor. replaced and all was fine. mine was bogging at 4k like i was hitting fuel cutoff or a speed limiter..

 

ambient temp sensor does absolutely nothing for the ecu and tuning. You can remove it and nothing will change. The ecu only reads INTAKE temp sensor that is located in the MAF.


Cog belt on or off will make no difference with airflow when the car is in vacuum because the BPV is open therefore all the excess air escapes through the BPV. That's why it is acting the same in vac with or without your cog belt on. It's not a supercharger issue.

Without seeing logs of both banks for a/f ratio it is hard to tell. There are only 3 things to cause an issue: spark, fuel, air. We know the car is getting air so it's probably one of the other 2. Without logs it is going to be very hard to diagnose unless you want to just start changing parts.

 

Thanks for the info I think I will start with getting a few logs to check
both MAF voltage and A/F as well as throttle voltage and go from there
I will then check for a faulty throttle body and clean the MAF.

This is the first problem so far with the car!!

 

Codes?

 

No codes checked twice

waiting for throttle body after speaking to RT Tuning that is the most
likely problem that has that symptom occurred before.

Will post results

Thanks

 

Well I just received the new throttle body and installed it and hooked everything back up (MAF seemed OK) nothing in pipes to suggest any
supercharger problems all very clean but still same thing.

But it will pick back up the RPMs if I slowly bring it to 2500 and tap on the throttle it will close the bpv and drop rpm like it will die then jump up and rev. from an idle it will kill it and idle will go rough in and out.

Will need to make a few logs but it is pretty much undrivable with the belt on so it will need to be parked and try to make it respond a few times with the same throttle input and starting RPM.

I hope this will show the issue.

Thanks again.

 

you make sure the MAF isnt put in backwards?

 

I wish no it is on correct thanks...
But just thinking is this a problem that could be a bad MAF ?

 

could be. try cleaning it. There were a few times people posted problems and they put the maf in backwards so the car ran but didn't register the correct flow since the airflow wasn't directly over the maf wires.

Nothing can be done until there are logs.