Hopefully someone can help with a dsm related issue. 2g 4g63 2g maf & tial bov.

Anyone have their bov sound just change out of nowhere? Mine used to be more of a flutter and now it's a phst that is really loud, even at 3psi shifts it's loud.
Also if I rev to 2k and let it drop the car will stall. This just all happened the other day while driving, never had this problem before and I've had a tial bov for over a year.

I did a boost leak test and found 2 very very small leaks. Fixed them both and it's still acting the same.

And upon acceleration 2k-2500rpm it bogs really bad. If I give it 50% throttle it will be fine.

I am wondering if this can all be related to a maf issue.

 

what pound spring do you have in the BOV?

 

White spring, 9psi.
Lots of people are saying it's because I upped the boost (which I never really did, I just fixed the boost leak) but if that were true how would it affect free reving at idle.

 

This is odd but try it.

1.) Check to make sure your plugs are properly tightened.
2.) Then with the car running see if the BOV is leaking any air by putting your hand around the vents.
3.) Check to see if your MAF screen has been pulled in any.

Email me your logs Paul.

 

Hmm, I never thought about the maf screen, I'll check it out today. I checked the bov and it's not leaking at all.

I will check the plugs late tonight when I get home from work.

 

It sounds like what happens when the MAF isn't getting a good signal for a IC pipe coming off and the ECU is going into limp / open loop mode.

If your BOV sound just got a whole lot louder it would seem to point to the BOV is no longer recirculating back into the intake. Check the hose from the BOV to the intake to make sure it hasn't come off because that wouldn't show up on a boost leak test.

that's the only thing i can think of that would explain a louder BOV sound... so aside from that and assuming the recirc pipe is still attached, you could check the following for your MAF:

Make sure the MAF dongle is plugged in all the way and there's no moisture in the plug. If you've had the MAF off recently (it's silly I know...) make sure it's on the right direction, and make sure there's no gaps where it bolts to whatever it bolts to & the hoses in front of and after the MAF are on tight.

If you log your air Hz you should be able to see if the signal from the MAF is messed up.

 

I've herd you need at least an 11lb spring to work properly if you have a MAF sensor.

 

It's a tial w/o recirculating back to the intake. The bov did get a whole lot louder also.
I reseated the dongle and it was in all the way and looked at it last night, dry as a bone.
I tightened them all up last night as well. I have logged my airflow hz and it seemed normal. I'll look again. I'm on ecmlink so you guys would need the program to see it.

 

I'm pretty stumped then.

I have one last one for you to check before I'm empty.

Pull the tial apart to see if there's a tear in the diaphragm.

Aside from that i really have no idea why the sound would change so noticeably.

Did your other symptoms (bogging while accelerating and stalling when letting revs drop ) at the same time as the noise change or were they always there?

 

Pretty much the same time with the bogging. The car would hiccup at 2k rpm for about a month now and I figured the maf needed to be cleaned or replaced. I cleaned it but it didn't help any.

 

I believe you need the 11lb spring so it stays closed around 2-3k Rpm that would explain the bogging.

 

I have an 11psi spring I can try, but I never needed it before so I wonder what changed.
Could the isc be the issue at all? It's not idle surging though, that is what someone else suggested on ecmlink forum.

 

Here is where I'm at so far.
Pulled out the spark plugs and they all look good.
Pulled out the maf and checked the screen, Nice and secure. Sprayed some maf cleaner on it too.
Pulled out the isc and tested it and everything ohms out to 29ohm or 30ohm, so that is good. I resealed it and put it back on.
Put the 11psi (uncolored) spring in the tial bov. Lost a screw in the process after it flew off (good thing I had a backup)
Checked out the diaphram and it's mint, no tears or nothing going on in there.
Pulled off the intake pipe and reclamped all the ends.
Inspected the vacuum line going from the valve cover to the intake. No problems there.
Inspected the vacuum line going from the SMIM to the tial bov and no problems found there either.
So I'm back to square one because it's still acting the same.

 

What do you have the ability to log?

And does ecmlink have the ability to export logs in .csv file format?

If so, could you log timing, afr, maf hz, knock sum, rpm and post it or e-mail it?

Without seeing a log or being able to test stuff... I'd just start checking easy things like pulling the valve cover off & doing a quick visual, compression test, change out plug wires or coils / distributor (sorry i don't know what it has), check the ground cables...

Sorry I can't really give any better input

 

I can log almost anything. Sorry no .csv files.
Ground cables are all good, I added one to the throttle body (just took it off when I did a boost leak test) I know they are good since I have a new alternator and battery and finally I'm getting a steady 13.5v
I checked all the plugs and wires they are all good. No distributor, it's a coil pack.
Let me do a log and I'll see what I can send you.