car won't boost? power fc

[poweredbysohc]

Alright guys. I Know I've Been dead for a while now, but I'm running into issues with a new s13 I picked up. It's a blacktop sr with a powerfc ecu. When ever the car goes into boost, it just retards timing a ridiculous amount so it doesn't want to stay in boost. Also, my fc commander doesn't show boost, so that leads me to believe something maybe have gotten disconnected and not put back on when the previous owner changed the turbo? Does anyone know where the ecu is supposed to get its boost reference from? I believe this is where my issues lie. I did a leak test and check the coils( slip fires, so I hope they're good) and the maf sensor and everything seems to be in order. Thanks in advanced guys.

[e1_griego]

The pfc doesn't show boost unless you have the boost control kit.

Are you sure you don't have a boost leak?

[poweredbysohc]

Well the previous owner was not mechanically inclined what so ever. The guy before him told me that it did show boost when he had the car. How is the ecu supposed to know then when the car is in boost and how much timing to retard if it doesn't know boost? And I'm 99% sure no leaks.

[e1_griego]

I'm assuming the car has a maf sensor?

[poweredbysohc]

Correct. It does indeed

[e1_griego]

That's all it needs. The ecu just reads airflow and compensates accordingly.

[poweredbysohc]

Copy. So what could be the issue?

[cotbu]

Copy. So what could be the issue?

The new owner!

Sent from a Highly Tuned Note 4.5!!!

[poweredbysohc]

I don't think that's funny. Haha. I guess I should re phrase my original statement. The car does boost, but it runs like garbage doing so. If you stay out of boost, it runs just fine. Any thoughts?

[cotbu]

Get a mechanical boost gauge, install that to very boost, then tell us the Wide-band reading. Log your pulls, do pulls in third or fourth. Try to document for us when and what you're doing when it happens. You might just need a tune.
So tell us what the mods are, if any. Pull codes.
Timing is supposed to retard, but if it's too much, it'll fall on its face.
So no I really can't just guess, but someone might get lucky.

Sent from a Highly Tuned Note 4.5!!!

[RussianSyndicate]

maybe the map sensor is not connected to the ECU. I'm a noob when it comes to FC commanders and other gadgets like it, but how do you know that it is retarding timing? If it truly is retarded, then I would check you knock sensor.

[poweredbysohc]

Get a mechanical boost gauge, install that to very boost, then tell us the Wide-band reading. Log your pulls, do pulls in third or fourth. Try to document for us when and what you're doing when it happens. You might just need a tune.
So tell us what the mods are, if any. Pull codes.
Timing is supposed to retard, but if it's too much, it'll fall on its face.
So no I really can't just guess, but someone might get lucky.

Sent from a Highly Tuned Note 4.5!!!

car has a wide band and a boost gauge. When it builds boost, it still has solid afrs, it's ~12.5.
The car has fmic, bov, isis turbo manifold, aeromotive fpr, and full exhaust. The previous owner said he had the turbo swapped at a shop from a t28 to a t25 and they told him it needed a tune and that's why it's running like shit. But. I refuse to believe going from or to either of these turbos will cause the car to act the way it is. The "shop" also did very shotty work. Radiator hose couplers, maf sensor not even clamped to turbo just pressed in, o2 sensor not even hand tight ect.

[poweredbysohc]

maybe the map sensor is not connected to the ECU. I'm a noob when it comes to FC commanders and other gadgets like it, but how do you know that it is retarding timing? If it truly is retarded, then I would check you knock sensor.

The knock sensor is currently disconnected. I reconnected to see if it made a difference, and it did not.

[poweredbysohc]

The knock sensor is currently disconnected. I reconnected to see if it made a difference, and it did not.

sorry to bring a post back from the dead but I fixed the problem. CAS was not put in properly so the timing was very retarded! car has been fixed for awhile now but figure I should post in case anyone comes across this and wanted to know the fix.