Why is it dying?

[Bunta]

Ok yesterday me and my buddie installed (on my 1990 Talon TSi):

Super AFC-II
Greddy Profec B Spec II boost controller
2gmaf w/ dejon intake arm
Upper IC w/ Tial BOV
Walboro 255 HP FuelPump
(stock everything else)

We have it tuned similar to the RRE 1gTurbo 16g setup. When I drive it and go to a stop or when I'm not in gear/ on neutral, the car dies. Is this because A) He's using stock injectors B) The AFC isn't tuned correctly C) The 2gMAF is wired wrong? D) The Tial BOV is vented to the air

If it is the AFC then which part on the AFC should I turn up or down.

Please Help,
Thanks!

[CornFed2.4]

D

[CornFed2.4]

D) is the answer I would say... When you rev it in neutral does it kill, or just in neutral period? I love mulitple choice. I thought you couldnt idle vented unles you had a translator

[Bunta]

When I'm on idle the car is fine, revving it and everything. But when I start to drive the car and go to neutral for the stop sign or light the rpm drops all the way down to 500-350 then it dies, sometimes it finds it's way to bounce back to 1000rpm but sometimes it dies.

From what I remember you can vent the BOV, but you'll be running rich in between shifts.

[CornFed2.4]

From what I remember you can vent the BOV, but you'll be running rich in between shifts.[/QUOTE]

Thats true also but mine always died try to recirc it and see if it goes away

[Shane@DBPerformance]

Stalling when coming to a stop is the main reason people recirculate the BOV. You also sometimes get harsh bucking at part throttle with stock turbo 2Gs when the BOV is vented.

[Bunta]

So Shane are you saying that the BOV is causing the car to die.

[Shane@DBPerformance]

It's the mostly likely suspect, since it's an extremely common problem with vented BOVs.

BOVs open at high vacuum. So when you are coasting to a stop the BOV might be partially open. On a car that has a recirculated BOV, the BOV will suck air up the recirc tube, which is fine because the air it is pulling in, has already been metered by the MAS. On a vented BOV, the BOV sucks in unmetered air, then the car goes lean and dies. Sometimes the closed loop O2 sensor feedback will be able to compensate for it and add enough fuel to keep the car running, other times it doesn't see it quick enough and just stalls.

[awd-drifter]

doesnt the S-AFCII fix that issue when tuned? or do you some more mods to do so?

[Pimpin Dsmstyle]

Originally Posted by awd-drifter

doesnt the S-AFCII fix that issue when tuned? or do you some more mods to do so?

A GM maf + translator fixes that problem.

[HiImBrian]

I have a 2g and I have a recirculating 1g bov. I've vented to the atmosphere before just to hear a little more pshh, and my car has never stalled out on me. Granted, I only do this for short periods of time. Just thought that might help

[TheBlizzard]

Either way its not what you are supposed to do. The metered air should be circulated back into the system. You make get away with it but there is no gains from it at all. There is only draw backs, if you want to hear the pshhhh sound then buy one of those whistle tips that go whoooo whoooo.

Your problem is probably the vented TIAL. I have no clue why you went with a TIAL when you are still using the MAF, it doesn't make sense, you probably didn't do you homework before you bought the parts.

Your only way to a decent running car is to get a MAF translator or a standalone that will not care if you vent to the atmosphere.

And no the AFC will not compensate for venting the BOV.

[Kevin 1G Drummer]

Another thing that could be contributing to the vented bov could be the 255 hp. A friend of mine had one in his car without an aftermarket fuel pressure regulator and at idle it would run way rich and sometimes stall out cuz he was overpowering the stock pressure regulator.