Running rich under light acceleration and overboosting

[Irace86.2.0]

Originally Posted by 1Saucyyy_brz

A bit of an update for you. I adjusted the vacuum lines to the wastegate to match what was in the video (leaving the top port open to atmosphere) I am no longer over boosting and the wastegate opens up all the way. But here's the problem, even though the wastegate us opening i am only making 10lbs of boost. The restrictor pill is still in place and hasn't been touched. I've gotten in contact with the new tuner at the shop I've gone to and explained to him my over boosting issue and now the issue of not hitting target boost pressure. He said the easiest way for me to manage my boost is to ditch the restrictor pill and install a manual boost controller. He recommended to me either Grimmspeed or Hallman (if you have any experience with either of these products I would like to know.) But, I think it is safe to say that my boosting issues are fixed. Thank you again for your input and time.

As far as the running rich situation I was told to try putting back the EVAP purge solenoid and just hard wiring it (because the harness is no longer there.) So that next on the list. I also noticed something a bit peculiar on the way to class today.. while looking at all the parameters on my phone i noticed that the fuel pump duty was in the 60% range while casually accelerating and, every now and then would randomly flicker to 70% while still casually accelerating. Also I noticed the fuel rail pressure was on the higher side (probably because the pump duty was high) but these were just some important things I figured I should mention. I'm looking around my local area for a shop that will smoke test my car.

I don’t know exactly how you have the vacuum lines routed. Do you just have a vacuum line running from the intake manifold area teed off the brake booster line to the side of the wastegate and that is it? And is the pill in this one vacuum line? Did you buy the pill, so you know what size it is and can confirm for sure it is designed for 18 psi? Or was this a trial by error thing to get to 18 psi?

I was going to suggest a manual boost controller earlier, but technically it isn’t much different than your restrictor pill; like the pill, they restrict flow. Alternatively, some bleed boost instead. Each has its advantages. It is a cheap and easy way to add boost or you can have them tune your EBC, which is typically better because there will be a line going to the top of the wastegate keeping it shut until the last possible minute, so there is no crack of the wastegate or spike.

Why was the harness ruined? They asked you to wire the EBC into the EVAP wires, and it went sour? Are you talking about this short line or the actual main engine wiring harness?




If it is just the small harness, I have seen used lines for cheap. You might be able to buy a new OEM/aftermarket EVAP harness for cheap too.

https://www.ebay.com/itm/2013-2018-S....m46890.l49292

Getting back to the rich issue: obviously the lines running to the EVAP are still attached to the solenoid, right? Hopefully fixing the EVAP wiring fixes some fueling issues, but let’s say it won’t. Are you running low compression on pump gas or stock compression on E85? What injectors? Aftermarket fuel pump or not? It could be a vacuum/exhaust leak. A smoke test would be good to test the vacuum system. Soapy water on exhaust components to test for air leaks there. Any chance they didn’t calibrate the injectors right, so you have larger injectors dumping in too much fuel because they are opening too long like the stock injectors would? Low speed is typically more direct injectors, so maybe there is an injector seal leak or something. Probably far less likely. I would think simply. Do you have a datalog that you can upload to Datazap and post here along with the specs I requested above?