Replaced 2 injectors and tune is totally out of whack.
Posted: Thu Jun 15, 2023 3:00 am
Hi,
First all I am a tuning noob. I am decent at working on the mechanical side of my car but as for wiring and tuning, it's almost a foreign language.
I have a k20a2 in a 2003 Civic sir. I have a prb ecu and trans with exedy stage 1 clutch, lightweight flywheel (around 9-10lbs) mfactory helical diff, RBC ported to 72mm (TB side only) skunk2 thermal I'm gasket, 72mm ktuned tb, kpro v4, Aem 3.5" Cai, skunk2 alpha 421 rh (2.5") running to a yonaka 2.5 exhaust that had slight fabrication to clear my progress rear sway bar. I also have Aem uego x wideband and guage, baffled sump and all the geometry and suspension done. .
All of these parts were installed in the last 6 months and I have only done about 3500 kms since the build. I also have brand new timing components (OEM) and oil pump chain. The car was on a street tune and was running fairly well, especially at the track which is where this car spends 90% of it's time. I began to experience rev hang, high idle and stalling issues, All lead me to beleive either iacv, TPS or injector. I bought a new fuel rail and the pintle can and oring on cylinder 1 got stuck in the RBC. That explained all my symptoms.
A friend of mine gave me a set of four injectors and told me he believed they were form a k20a2. Anyway I fished out the cap and oring (with a Dyson because I dropped it into the manifold lol) everything came out a ok. So I pulled the bad injector out and installed the best looking 1 from my friends set. I only replaced cylinder 1 as all 3 other injectors looked healthy and put new o rings on. The injector turned out to be a a3 (270cc) against my other 3 OEM prb 310cc's.
So I reached out to another friend who I met today and he gave me 2 k20Z3 injectors. So I pulled the the worst a2 injector as well as another one that looked ok, but no where near as. Clean as the newer z3 injectors. I staggered them 1 prb then 1 z3 and repeated in the last 2.
I started the car and I immediately noticed it running better. However my aem wideband was reading 16-18/3-7 afrs. I figured with two 310ccs from the z3 would be almost identical to the a2s. So I plugged in and downloaded my street tuned map done by the shop that did some of the above mentioned work. I noticed the z3 injectors had a slight round edge on the metal caps, but they were the same in size other than that.
Long story short kpro kmanager was reading 14.6/14 7 at idle where as my aem wideband was reading the higher afrs mentioned above. I hope this isn't a stupid question but wouldn't all injectors with a 310cc rating behave the same based on my previous tune. This was not the case
A. Which reading do I beleive is more accurate? Kpro v4 or Aem wideband
B. Does the slightly different shaped metal cap make a big difference with spray pattern, or atomization make that big of a change 3D between my afr's?
C. Is there anything I can calibrate within the app, say a setting about the I injectors without having to try tune the variance out?
D. Should I just buy a matching set of OEM injectors 310ccs as I was topping out at 82% duty on the prb 310s before the one broke.
E. Should I leave these injectors in and just get a re-tune?
F. Or should I just get rdx 440s o a set of deutchworks (similar cc I think 350 or 55p with a higher flow rate, to future proof the car and get a re-tune.
Sorry for the rant. I just wanted to get some advice on what direction is most likely to make my car run well again. I plan on leaving the car.na as it's just my reliable track toy.
Sorry there is no data logs but I only got the car running again tonight.
Thanks so much in advance!!
First all I am a tuning noob. I am decent at working on the mechanical side of my car but as for wiring and tuning, it's almost a foreign language.
I have a k20a2 in a 2003 Civic sir. I have a prb ecu and trans with exedy stage 1 clutch, lightweight flywheel (around 9-10lbs) mfactory helical diff, RBC ported to 72mm (TB side only) skunk2 thermal I'm gasket, 72mm ktuned tb, kpro v4, Aem 3.5" Cai, skunk2 alpha 421 rh (2.5") running to a yonaka 2.5 exhaust that had slight fabrication to clear my progress rear sway bar. I also have Aem uego x wideband and guage, baffled sump and all the geometry and suspension done. .
All of these parts were installed in the last 6 months and I have only done about 3500 kms since the build. I also have brand new timing components (OEM) and oil pump chain. The car was on a street tune and was running fairly well, especially at the track which is where this car spends 90% of it's time. I began to experience rev hang, high idle and stalling issues, All lead me to beleive either iacv, TPS or injector. I bought a new fuel rail and the pintle can and oring on cylinder 1 got stuck in the RBC. That explained all my symptoms.
A friend of mine gave me a set of four injectors and told me he believed they were form a k20a2. Anyway I fished out the cap and oring (with a Dyson because I dropped it into the manifold lol) everything came out a ok. So I pulled the bad injector out and installed the best looking 1 from my friends set. I only replaced cylinder 1 as all 3 other injectors looked healthy and put new o rings on. The injector turned out to be a a3 (270cc) against my other 3 OEM prb 310cc's.
So I reached out to another friend who I met today and he gave me 2 k20Z3 injectors. So I pulled the the worst a2 injector as well as another one that looked ok, but no where near as. Clean as the newer z3 injectors. I staggered them 1 prb then 1 z3 and repeated in the last 2.
I started the car and I immediately noticed it running better. However my aem wideband was reading 16-18/3-7 afrs. I figured with two 310ccs from the z3 would be almost identical to the a2s. So I plugged in and downloaded my street tuned map done by the shop that did some of the above mentioned work. I noticed the z3 injectors had a slight round edge on the metal caps, but they were the same in size other than that.
Long story short kpro kmanager was reading 14.6/14 7 at idle where as my aem wideband was reading the higher afrs mentioned above. I hope this isn't a stupid question but wouldn't all injectors with a 310cc rating behave the same based on my previous tune. This was not the case
A. Which reading do I beleive is more accurate? Kpro v4 or Aem wideband
B. Does the slightly different shaped metal cap make a big difference with spray pattern, or atomization make that big of a change 3D between my afr's?
C. Is there anything I can calibrate within the app, say a setting about the I injectors without having to try tune the variance out?
D. Should I just buy a matching set of OEM injectors 310ccs as I was topping out at 82% duty on the prb 310s before the one broke.
E. Should I leave these injectors in and just get a re-tune?
F. Or should I just get rdx 440s o a set of deutchworks (similar cc I think 350 or 55p with a higher flow rate, to future proof the car and get a re-tune.
Sorry for the rant. I just wanted to get some advice on what direction is most likely to make my car run well again. I plan on leaving the car.na as it's just my reliable track toy.
Sorry there is no data logs but I only got the car running again tonight.
Thanks so much in advance!!