Extremely rich: (VPC) + (S-AFC)

[MK3Brent]

Just finished putting in the VPC with 550 chip.

With zero correction on both the VPC and AFC, my air fuel ratios are RIDICULOUSLY rich. 8:1 before redline.



Just curious if anyone else's VPC AFC combo ever went that rich.

mods if you need to compare:

550cc injectors, walbro pump, AFPR.
GT4088 turbo.

 

[rs4rush]

Im running the same thing exept I have 720cc injectors. I have some funky problems too. The sad part is i'm running lean????? The high throttle is set correctly and still I lean out. I'm going to get it tuned and see what happens from their.

 

[tubbie]

Check your fuel pressure. Mine was ridiculously rich from idle to redline. I had to drop the fuel pressure to get it to run normal. I have the 12v mod and pressure was at 42psi idle. I had to drop it to 32 psi and I could zero out the VPC and AFC.

550cc, mk4 tt pump

 

[tissimo]

what chip is in it?

 

[dbsupra90]

yeah they run pretty damn rich w/ the 550 chip. id use the 440 chip if you have it.

i still wouldnt expect THAT rich tho. like was said, you may need to back down the fuel pressure.

 

[MK3Brent]

I think I posted too soon... the car is running fantastic right now actually.

Does the VPC really "learn" or was that some story people have made up?
Because I'd believe it now.

I have the 550 chip installed.
At 14.5psi I need to take out -10% correction across the RPM range, and with 20psi I need 0 to +1,+2% correction.

I'm really enjoying the VPC right now, the response and smoothness of the speed density is really noticeable.

+1 Purchase.