I am finishing my car up finally and have run into a problem.

I have an HKS pfc-fcon and am wondering if I need the AFM?

It starts up fine without it. We are having idling surges sometimes and at random times it wont really accelerate and will bog. We think part of those problems were our vacuum lines. We are going to relocate a few and we think we ran a couple to the wrong places.

Also there is a vacuum line that runs from what i think is the bac valve on the intake manifold and it runs to my intercooler pipe by the throttle body(Old HKS FMIC). That vacuum line has a sensor thing built into it and I am wondering what plugs into it.

I also have the HKS AIC, EVC(electronic boost controller), SBC (boost scrambler)

I can't seem to find anything with the searches talking about this. All the HKS pfc f-con searched threads end up the same way I think.

 

1. The ECU does not use the AFM for starting the engine at all.

2. When the signal from the AFM is open to the ECU, the value of the afm signal is defaulted to a preset value.

3. So taking the first two into consideration, you can see why the engine runs with the afm disconnected.

4. You have to use the AFM, yes.

 

Unless you go Standalone and run a map sensor then is whole different story.

 

Or you can use the piggyback mapecu which replaces the afm and it is a piggyback NOT a standalone. -mike

 

Whoa been a while since I've posted

What gen car you have?

If you have an S5, hunt down a HKS VPC unit for the FC (need help pm me). It goes with the F-con and removes the need for an AFM. It's a deleted piece of hardware now from the same generation as the PFC - Fcon's. These fella's aren't cheap though, even used...