I'm to lazy to look back at all the prior posts. You have changed the fuel filter haven't you?
One other thing to try data logging if you haven't already looked at is the comparison of pump duty cycle and fuel pressure in relation to A/F.
__________________
ANSWERS
Off the cuff______________________ $0.25
Requiring Thought__________________$0.50
Correct and requiring thought________ $1.00
DUMB LOOKS ARE STILL FREE
I think he said it is good under load and at WOT its more like a part throttle deal. Not really sure though.
__________________
ANSWERS
Off the cuff______________________ $0.25
Requiring Thought__________________$0.50
Correct and requiring thought________ $1.00
DUMB LOOKS ARE STILL FREE
If he had aftermarket fuel rails I might suspect those! Did you ever remove your MMR rails?
I did and it really helped but I had so many other things fighting me I wasn't sure if they were a problem or not. They are back on right now while the car is at the dyno and they seem to be ok.
__________________
ANSWERS
Off the cuff______________________ $0.25
Requiring Thought__________________$0.50
Correct and requiring thought________ $1.00
DUMB LOOKS ARE STILL FREE
I did and it really helped but I had so many other things fighting me I wasn't sure if they were a problem or not. They are back on right now while the car is at the dyno and they seem to be ok.
Mine have remained off for now. Unless I can figure out how to feed the fuel from the front of the d/s rail.
STL, I am thinking this is a tune issue. I know these cars has an inherent issue around the idle stabilization, especially when you add cams and SC. I see he has the Stage 2 Comp cams, although a blower cam, he could still be seeing these same issues, especially with his rpm settling out at 750. Both of my Foose cars with the cams did that, especially with the rpm below 800. The canned Brenspeed tune fixed it on my latest car, but it came back somewhat when I had them tweak the tune recently for more HP. The first tune ran good for about 6 months with very minimal idle fluctuation. With this one, some days it seems better than others, but you learn to deal with it. So my vote is that this issue is probably tune, not fuel volume or pressure.
__________________
Victor
2007 Foose Stallion "The Prowler"
FRPP Polished Whipple SC - 8lb boost, FRPP Hot Rod Cams (M-6550-3V), FRPP Ceramic Coated Shorty Headers, FRPP Tuned Racing Suspension, FRPP Tuned Racing Exhaust, FRPP Axle Back, Steeda TriAx, Nexus Series - AFM, Vac/Boost, Fuel Pressure, Speed of Sound Dash Pod, Raptor Blue LED Shift Light. 425 RWHP 387 TQ
Yeah, I replaced the fuel filter.. The idle issues are very indicative of a bad throttle body, but I have not found a complete throttle body to swap into it to test, and I am not going to spend the money on a complete new setup unless I know it will fix it. I have examined and cleaned the factory TB and it appears perfect.. no binding, the action is smooth, and the tps meters smoothly across the range of throttle position. That's not to say something isn't bad, but since the issues are all intermittent, I would expect to see some glitch or catch in the TB, and I don't. I am running out of things to replace or fix.
After the weekend, I intend to remove the BAP (bypass it for now) and test, but I am not hopeful as I have metered the output and it seems solid. Replacing the FPDM is another thing to try, but I have been watching and datalogging the Fuel Pump Duty Cycle and the Fuel Rail Pressure and I have not seen anything that would suggest the pump is not getting the voltage. If anything, the PCM is a little slow to react, but usually pressure doesn't drop below 35 psi, even when the bogging problem occurs.
For the last test, I reloaded the original KB tune, and was able to recreate the issues over and over for a good 3 minutes. While the engine was sputtering and popping, fuel pressure dipped a little, but FPDC seemed normal, jumping a little on throttle, which was to be expected. If the driver was failing (or the BAP) I would think the duty cycle would drop..
I am looking back to the tune issues. The latest tune seems to have pulled fuel (Ken at KB didn't tell me what he adjusted, I think he wants to see results without clouding things with my opinions or analysis - probably a smart thing to do). The LTFT is substantially closer to zero with the latest tune he sent me, and is at flat zero at WOT and everything seems fine.. If anything, when the engine is cold it is running a tad lean (11.8-12 at WOT), but once warmed up it runs where it is tuned (about 11.3 at WOT). The bogging issues is still there but greatly reduced, and the idle issue is getting worse as the days pass, which is very frustrating. I feel like I am missing something.
If anyone has datalogged recently, what kind of LTFT's were you seeing at idle? My bank 1 LTFT is around -7, but bank 0 is around -1 with the latest tune, but with the regular KB tune bank 1 was around -18 while bank 0 was around -9 or -10. I think the base tune was way too rich and the pcm was pulling fuel, but in open loop it ignored ltft and stayed too rich, possibly flooding the cylinders and dousing the spark. That was the direction we were looking at before I started looking at the fuel pump, and now that the fuel pump is a bust, I am leaning back that direction.
For now, I am focusing on getting ready for our big show. I started repainting some parts under the hood last night and I need to wash and wax the whole car, then detail everything again. Between paint and buffing/waxing, my next few days are way too busy to be trouleshooting these problems. Furthermore, the weather has been crappy, and I haven't gotten much opportunity to drive. I hope we get good weather for our show.. there are people driving over 400 miles to be here.. it would suck to have rain all day..
__________________
____________________
2006 GT Premium Vert, 5 spd, Tungsten Grey Show: Painted gloss black stripes, Street Scene Gen 1 body kit, side and hood scoops, CDC light bar, sequential tails, purple underglow, 8" shorty antenna, redline hood struts, Steeda Ultralights, 20" Chrome Killers, S.O.S. pillar & 3 gauges. Go: J&M LCA's & Adj. UCA, J&M Adj. Panhard, CHE LCA reloc brackets & torque limiters, 3.73 gears, Kenne Bell Stage 1 2.6l supercharger.
...440rwhp/401rwtq
No, what should it be? I couldn't find a reference, so I just pulled the whole assembly apart and checked to see that it had a smooth change in resistance as I turned it back and forth.
__________________
____________________
2006 GT Premium Vert, 5 spd, Tungsten Grey Show: Painted gloss black stripes, Street Scene Gen 1 body kit, side and hood scoops, CDC light bar, sequential tails, purple underglow, 8" shorty antenna, redline hood struts, Steeda Ultralights, 20" Chrome Killers, S.O.S. pillar & 3 gauges. Go: J&M LCA's & Adj. UCA, J&M Adj. Panhard, CHE LCA reloc brackets & torque limiters, 3.73 gears, Kenne Bell Stage 1 2.6l supercharger.
...440rwhp/401rwtq
heh.. exactly the problem.. the issues are intermittent, so I know nothing will look wrong when just looking at it statically.. I have this suspicion that replacing parts is going to be the only way to find what is wrong..
I tend to get so focused on the problem that I forget how fun it is when the engine is warmed up.. Weather was great today so I took it for a spin.. almost went sideways passing someone in second.. Gotta love that..
__________________
____________________
2006 GT Premium Vert, 5 spd, Tungsten Grey Show: Painted gloss black stripes, Street Scene Gen 1 body kit, side and hood scoops, CDC light bar, sequential tails, purple underglow, 8" shorty antenna, redline hood struts, Steeda Ultralights, 20" Chrome Killers, S.O.S. pillar & 3 gauges. Go: J&M LCA's & Adj. UCA, J&M Adj. Panhard, CHE LCA reloc brackets & torque limiters, 3.73 gears, Kenne Bell Stage 1 2.6l supercharger.
...440rwhp/401rwtq
