roadtrip_69
15+ Year Contributor
- 66
- 9
- Apr 18, 2008
-
Cincinnati,
Ohio
Anyone,
Problem is I can not get the fuel flow/latency tuned in at all. And I'm at my wits end because it doesn't make any sense at all. Runs rich at idle but surges (responds very slow to throttle after being at idle or low throttle) and runs really lean at even partial throttle and AFR is all over the place the wider the throttle is open.
Here are the relevant mods
Authentic Wallboro 255lph HP pump (Brand new!), an Aeromotive AFPR (year old or so) and FIC 850CC injectors, BRAND NEW Stock Fuel Filter, rewired fuel pump with direct connection to the battery. And a wideband that is set up in the factory 2nd O2 bung, also wired into the ecu to log with. Using EVOscan and ECUflash as my modding and logging tools.
Things I've tried.. Adjusting fuel flow from the intended 850cc down to 690cc in Ecuflash.(car does run decent at the low setting of 690 but still has inconsistent AFR's with steady boost/throttle, and obviously is way underflowing what it should) I also sent the injectors back to FIC for a fuel flow test and leak test. They tested good. and average 830cc between the 4 with less than 1% variance. Tested and monitored TPS and it has a range of 12 % at idle to 100 at full press.
I've tried all types of latency changes, FIC sent me a very detailed spec sheet of multiple flow rates and latencys at different psi's. And while I can get IDLE and Cruise decently set(though idle is always richer than cruise, its WOT or anything above 20-30 percent throttle that AFR's are very inconsistent and typically very lean. I have my fuel map set to 11.0 at all loads above 100 for ease of tuning, and even taking into account the 1 or 2 second delay of the rear o2 location. The AFR's are way leaner than they should be and not consistent.
I also while replacing the fuel filter 2 days ago, disconnected the line from the fuel pump side, and blew pressurized air though the line between the pump and filter to make sure there are no clogs. So I know fuel should be getting to the filter at full volume/pressure. I checked the fuel hose from the filter to the rail for kinks and or leaks, and nothing. I also replaced the fuel hose coming off the fuel line to the AFPR. So also no restrictions. loosened the fuel rail and disconnected one injector and fuel came out, so injector is likely not "stuck" open(and again if it were, AFR would be RICH not lean! (though a restriction at this point or after would cause everything to run RICH not lean right? )
I also have read a few articles that mentioned some Aeromotive AFPR's have a seating problem, and cause pressure to leak through, which I guess would explain pressure holding at idle but either not raising or actually lowering at higher Throttle/RPM's? But when i took it apart, the hole for the return looked symmetrical and the ball/valve seal thing, while looking white/dried out/dirty a bit it was held together fine. I have adjusted the FP all the way up to 70 PSI for base pressure while at idle to see if it could adjust. I have it set to 43-44 psi with the vacuum line disconnected, and it drops to about 37 psi when vacuum line is attached. My boost gauge reads 19-20 in/hg at idle. Also, when i turn off the car the pressure in the line immediately drops to zero. Though I can not find a single leak(fuel) anywhere.
I have ordered a service kit for the aeromotive AFPR which arrives today and I will install, to see if that helps anything.
But does anyone have any idea what is going on or what I can check next? Could i over tighten the fuel filter some how and cause a restriction?(the old filter did appear to be clogged a bit, after installing the new one, base pressure raised 3-4 psi by itself) It did leak after I first installed it at the IN and i went back and tightened it up until it did not. But i have checked both lines, in and out, and neither seem to be kinked or bent more than normal factory bends.
Of note, I have a fmic with a 20g hybrid turbo, full 2 1/2 to 3 inch exhaust from the 02 Dump back(which is itself a SS part.) I have no leaks in the exhaust (though i did have a leak at the o2 dump/turbo connection till recently. Which i discovered because my wide-band was always reading super lean especially at idle but would richen up with more flow.) As mentioned before Vacuum holds steady at 19-20 in/hg at idle so no vacuum leaks i can find/tell.
Any ideas anyone?
Oh and on the occasion that the AFR richens up, the car does pull like a banshee, specially now with the new Wavetrac front diff i installed recently.
Attaching a log if that helps. This one is set at 757 CC Injector Rate, I will be setting it at 707 later just to regain some driveability and safety till I cant get this figured out! uuurrg
Problem is I can not get the fuel flow/latency tuned in at all. And I'm at my wits end because it doesn't make any sense at all. Runs rich at idle but surges (responds very slow to throttle after being at idle or low throttle) and runs really lean at even partial throttle and AFR is all over the place the wider the throttle is open.
Here are the relevant mods
Authentic Wallboro 255lph HP pump (Brand new!), an Aeromotive AFPR (year old or so) and FIC 850CC injectors, BRAND NEW Stock Fuel Filter, rewired fuel pump with direct connection to the battery. And a wideband that is set up in the factory 2nd O2 bung, also wired into the ecu to log with. Using EVOscan and ECUflash as my modding and logging tools.
Things I've tried.. Adjusting fuel flow from the intended 850cc down to 690cc in Ecuflash.(car does run decent at the low setting of 690 but still has inconsistent AFR's with steady boost/throttle, and obviously is way underflowing what it should) I also sent the injectors back to FIC for a fuel flow test and leak test. They tested good. and average 830cc between the 4 with less than 1% variance. Tested and monitored TPS and it has a range of 12 % at idle to 100 at full press.
I've tried all types of latency changes, FIC sent me a very detailed spec sheet of multiple flow rates and latencys at different psi's. And while I can get IDLE and Cruise decently set(though idle is always richer than cruise, its WOT or anything above 20-30 percent throttle that AFR's are very inconsistent and typically very lean. I have my fuel map set to 11.0 at all loads above 100 for ease of tuning, and even taking into account the 1 or 2 second delay of the rear o2 location. The AFR's are way leaner than they should be and not consistent.
I also while replacing the fuel filter 2 days ago, disconnected the line from the fuel pump side, and blew pressurized air though the line between the pump and filter to make sure there are no clogs. So I know fuel should be getting to the filter at full volume/pressure. I checked the fuel hose from the filter to the rail for kinks and or leaks, and nothing. I also replaced the fuel hose coming off the fuel line to the AFPR. So also no restrictions. loosened the fuel rail and disconnected one injector and fuel came out, so injector is likely not "stuck" open(and again if it were, AFR would be RICH not lean! (though a restriction at this point or after would cause everything to run RICH not lean right? )
I also have read a few articles that mentioned some Aeromotive AFPR's have a seating problem, and cause pressure to leak through, which I guess would explain pressure holding at idle but either not raising or actually lowering at higher Throttle/RPM's? But when i took it apart, the hole for the return looked symmetrical and the ball/valve seal thing, while looking white/dried out/dirty a bit it was held together fine. I have adjusted the FP all the way up to 70 PSI for base pressure while at idle to see if it could adjust. I have it set to 43-44 psi with the vacuum line disconnected, and it drops to about 37 psi when vacuum line is attached. My boost gauge reads 19-20 in/hg at idle. Also, when i turn off the car the pressure in the line immediately drops to zero. Though I can not find a single leak(fuel) anywhere.
I have ordered a service kit for the aeromotive AFPR which arrives today and I will install, to see if that helps anything.
But does anyone have any idea what is going on or what I can check next? Could i over tighten the fuel filter some how and cause a restriction?(the old filter did appear to be clogged a bit, after installing the new one, base pressure raised 3-4 psi by itself) It did leak after I first installed it at the IN and i went back and tightened it up until it did not. But i have checked both lines, in and out, and neither seem to be kinked or bent more than normal factory bends.
Of note, I have a fmic with a 20g hybrid turbo, full 2 1/2 to 3 inch exhaust from the 02 Dump back(which is itself a SS part.) I have no leaks in the exhaust (though i did have a leak at the o2 dump/turbo connection till recently. Which i discovered because my wide-band was always reading super lean especially at idle but would richen up with more flow.) As mentioned before Vacuum holds steady at 19-20 in/hg at idle so no vacuum leaks i can find/tell.
Any ideas anyone?
Oh and on the occasion that the AFR richens up, the car does pull like a banshee, specially now with the new Wavetrac front diff i installed recently.
Attaching a log if that helps. This one is set at 757 CC Injector Rate, I will be setting it at 707 later just to regain some driveability and safety till I cant get this figured out! uuurrg
