lots of lag, low on power...can't figure this out
- Thread starter tErbo b00st
- Start date
Thank you for all the help and suggestions! I am going to redo my PCV system. Will probably have to bring my intake pipe into a shop to have a vacuum nipple welded on.
I have improved on the setup a lot. My idle still seems to be a bit lean (pulling 25% fuel, but idling at like 16:1) but... I cleaned the IC out with gasoline and got A TON of gunk out. I also unhooked my AVCR and simplified some of the vacuum tubing, and my idle vacuum went from -13 to -16. This also put me at wastegate pressure of 16 psi, which means I'm now pulling a nice mid 11 AFR (adjusted the AFC a bit) and 90% injector duty cycle. The car feels MUCH better, very strong. The turbo now builds about 10 psi by 4500, starting at about 3500. Then at about 5000 I have full boost and the car rips. I still think something is off, because I believe I should be at about 80% duty cycle at 16 psi. But for now, the car is strong, my AFR is safe, and 90% duty cycle isn't too bad.
Next on the to do list is to swap in a known good OEM FPR or AFPR, completely redo my vacuum line setup, setup the PCV system properly, and try and get the injector duty cycle down to the 80% range.
Any more suggestions or thoughts would be great!
I have improved on the setup a lot. My idle still seems to be a bit lean (pulling 25% fuel, but idling at like 16:1) but... I cleaned the IC out with gasoline and got A TON of gunk out. I also unhooked my AVCR and simplified some of the vacuum tubing, and my idle vacuum went from -13 to -16. This also put me at wastegate pressure of 16 psi, which means I'm now pulling a nice mid 11 AFR (adjusted the AFC a bit) and 90% injector duty cycle. The car feels MUCH better, very strong. The turbo now builds about 10 psi by 4500, starting at about 3500. Then at about 5000 I have full boost and the car rips. I still think something is off, because I believe I should be at about 80% duty cycle at 16 psi. But for now, the car is strong, my AFR is safe, and 90% duty cycle isn't too bad.
Next on the to do list is to swap in a known good OEM FPR or AFPR, completely redo my vacuum line setup, setup the PCV system properly, and try and get the injector duty cycle down to the 80% range.
Any more suggestions or thoughts would be great!
I definitely would have an adjustable FPR on there. Helps a lot to adjust base pressure to match your fuel curve. I basically have mine where I am just pulling basically nothing up top. (I have no boost cut) At that point I have to pull high -2Xs at idle but I have a 2J ecu.
If it's not the FPR going lean up top, I wonder if you need to check/rewire/replace your fuel pump.
I had a similar issue where I was running out of fuel up top when wired through the stock fuel pump wiring, maxed out fuel at 437whp/389tq on a Walbro 255 + 550ccs and adjustable FPR, stock cams.
I rewired everything fresh with a new relay and now don't have that problem anymore. I'm pretty sure I've had it up to 500ish whp on this fuel setup.
As far as the turbo, if it's 600-ish whp capable setup, then ya it's gonna lag like terrible. My car on stock 1J cams and a 600whp capable single turbo used to be absolutely no power until 4000 and then it hit like a freight train to full boost at 4650ish. Now on 272s it has smoothed the spool out a bit, makes better power and boost leading into the spool up but takes a bit longer to hit full boost.
If it's not the FPR going lean up top, I wonder if you need to check/rewire/replace your fuel pump.
I had a similar issue where I was running out of fuel up top when wired through the stock fuel pump wiring, maxed out fuel at 437whp/389tq on a Walbro 255 + 550ccs and adjustable FPR, stock cams.
I rewired everything fresh with a new relay and now don't have that problem anymore. I'm pretty sure I've had it up to 500ish whp on this fuel setup.
As far as the turbo, if it's 600-ish whp capable setup, then ya it's gonna lag like terrible. My car on stock 1J cams and a 600whp capable single turbo used to be absolutely no power until 4000 and then it hit like a freight train to full boost at 4650ish. Now on 272s it has smoothed the spool out a bit, makes better power and boost leading into the spool up but takes a bit longer to hit full boost.
Wanted to give a quick update in case anyone finds this during a search.
Ran codes and found code 21 and code 22, bad O2 sensor and bad coolant temp sensor. Replaced the coolant temp sensor, and at the same time found that I had a really shitty connection on the power wire to my AFC. Rewired that and it transformed the car. I had to completely retune and the car is a rocket with a nice 11.5 AFR @ 85% duty cycle. Not sure if it was the AFC wiring or sensor that fixed it, but one of those worked! Fixed some bad wiring on the O2 sensor heater and idle and driveability (and idle vacuum) improved.
Thanks for all the help
Ran codes and found code 21 and code 22, bad O2 sensor and bad coolant temp sensor. Replaced the coolant temp sensor, and at the same time found that I had a really shitty connection on the power wire to my AFC. Rewired that and it transformed the car. I had to completely retune and the car is a rocket with a nice 11.5 AFR @ 85% duty cycle. Not sure if it was the AFC wiring or sensor that fixed it, but one of those worked! Fixed some bad wiring on the O2 sensor heater and idle and driveability (and idle vacuum) improved.
Thanks for all the help