i will assume that you read the entire TSB, especially the part about what causes the rough condition: air bubbles. this is exactly a cause for the symptoms you describe. spike into a lean condition/low fuel pressure. i would explore this more before anything else. i am currently struggling with the same problem. just on a much lesser scale. its almost not bad enough to fix. I'm in a tough position because my budget is shot this year because of my engine and my car is far past warranty. i will be looking at getting a GT500+return style system in a couple months hopefully.
__________________
2005 Mustang GT Paxton Novie 1200SL Supercharger, C&L 95mm Mass/Air sensor, 39lb injectors, Motoblue ignition coils, Motoblue throttle plate spacer, Borla XR-1 Long Tube Headers and no cat x-pipe, Hooker Aero Chamber muffler, Custom LaMotta Performance tune, G-force tires, B&M shifter, Kennybell b-a-p, Steeda streat wing, RKSport California Dream Ram Air Hood, AEM analog A/F gauge, Interceptor scan gauge, McLeod RST clutch
MMR shortblock all broken in!
intercooler/smaller pully to come...
I wish I still had my OEM pump. I'd just send it to you. Mayble someone else has one lying around.
Thanks, 10/5 is helping me out there, sending me his OEM to try. I am very grateful for help like this, it may end up saving me a lot of money in the end - something that is VERY appreciated.
I will give updates as I get them.
FYI, Today I datalogged again and I ran into something that leans me even further toward the pump being the problem (or at least convinces me it's a fuel delivery issue).
KB states in their instructions to NEVER go below 1/4 tank of fuel as the pump can suck the reservoir dry in hard accelleration or a turn. Well, I saw this while datalogging. I hit second coming out of a turn and dropped the hammer. The engine popped and sputtered, identical to the normal problem I have been having. I figured it was in fact the cold run issue and I was anxious to analyze the data. I realized after looking at the fuel pump duty cycle freaking out on the graph that I was low on fuel and must have sucked a little air. Thing is, the result was identical to my cold run problem. This tells me it is indeed not getting the fuel, and either that means a bad fuel pump driver, or a bad pump. Since the FPDM is showing normal duty cycle when I add throttle, I assume the pump just isn't delivering.
If the pump comes in before the weekend, I will get it swapped and test it out, otherwise I have to wait for next week, and I am getting dangerously close to the dyno day. I really want this running right for the dyno, because I have a couple custom tunes available I can try but am afraid to if I can't trust my fuel getting to the engine. The dyno pulls only cost $30 for the first and $10 for consecutive pulls.. Can't pass up some practically free pulls..
__________________
____________________
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
I sure hope that this does it! My eyes hurt from reading so much.
haha.. I tend to go on and on sometimes.. people complained that my emails and posts were like books, so I sat down and wrote a book this year.. a lot of fun.. Now I just need to find an agent to try to sell it to a publisher for me..
The more I think about the problem, the more I think it has to be fuel related.. if not the pump then the fuel pump driver.. That will be the next step if the pump doesn't work.
Did a 4th gear datalog today, didn't feel comfortable doing more than 115 through a construction zone so I let off at 5400 rpm.. man this thing pulls hard in 4th.. I was surprised.. only the third time i have had it in 4th since the supercharger went on, and the first pull in 4th I have done.. I have pulled all the way to the top of 3rd before, shifting at about 100 mph, but I never kept it going in 4th.. this time I did 3300rpm to 5400rpm.. Solid 11.4 AF all the way, data looked fine.. obviously the pump can do the volume with no problem. This was on an eighth tank of fuel too..
__________________
____________________
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
So I got a replacement pump today, and ran home on lunch break to install it. Installation, by the way, is damn easy in a convertible.. Took me about 25 minutes start to finish, 10 of which was spent fishing the passenger side fuel line up to where I could grab it. Tight in there..
Anyway, previously, if my fuel pressure was down, when I turned on the key, the old pump sounded like a horn honking behind me. I always thought that was odd. When I turned on the key this time, I could hear the pump build pressure, but it was very quiet. That got my hopes up quite a bit.
Then I started up and idled for a minute. Idle was smooth and seemed much better. I backed out of the garage, and while watching the fuel pressure, blipped the throttle, which resulted in a jump in pressure. That had never happened before, usually pressure didn't go up from 40 until I hit boost. Once again, my hopes climbed.
I installed the original tune just prior to this, because the tune I was running from KB forced it into closed loop even when cold, to allow the computer to correct the issues (at least that was the idea I think). The original tune would normally be difficult to drive with when the car hadn't been driven in a while (ie at least 5 hours). I took off right away and got into throttle with no hesitation. That seemed a good sign! I got out of my subdivision and hit the first main road. Immediately, the same symptoms came back. The engine was stumbling and the AF gauge showing lean when it happened.
*SIGH*
At the next light, the idle dropped to 300 and hung before jumping back to 1000 and settling at 750 after that.
So while it seemed to work fine for a couple minutes, it quickly changed back to how it was before.
So what is my next step? I am going to look at the FPDM and the BAP. My thinking is that it is still a fuel delivery issue. Since a replacement pump didn't cure the problem, I need to look at the other possibilities. Aside from injectors, the BAP was the only thing added to the fuel system when the supercharger went in. I have measured the output of the BAP, and it is correct, but that doesn't mean something isn't wrong when the FPDM or the BAP is cold.
Will it ever end?
__________________
____________________
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
My car was doing the same thing and it turned out to be a fuel pump.I chased so many dead ends and finally it turned out to be the pump.iT WOULD ONLY DO IT AFTER BEING DRIVEN HARD ON HIGHWAY AS SOON AS YOU ENTER TRAFFIC OR SIT FOR A WHILE PEDDLE WAS LESS RESPONSIVE IT WOULD BUCK AROUND 3500RPM.But when it was cold or cooler day the car ran awesome any sort of heat and back to running crappy.i CHANGED OUT PUMP NOW it runs awesome
Have you thought of completely changing your fuel system to a return style. It will eliminate a lot of the fuel pressure problems and make tunning easier. Like I previously posted, I have a stumble at tip in which is exagerated by a cold start. I had my tune tweaked but it appears the adaptive learning feature causes it to return. I just disconneted my battery overnight to reset everything and mine is back to driving like a charm. I have future upgrades in mind and I am pretty sure a return style fuel system will be one of them!
Have you thought of completely changing your fuel system to a return style. It will eliminate a lot of the fuel pressure problems and make tunning easier. Like I previously posted, I have a stumble at tip in which is exagerated by a cold start. I had my tune tweaked but it appears the adaptive learning feature causes it to return. I just disconneted my battery overnight to reset everything and mine is back to driving like a charm. I have future upgrades in mind and I am pretty sure a return style fuel system will be one of them!
I've thought about it, but it is very cost prohibitive. I don't intend to go over the 600 rwhp mark, even if I build the engine down the road, so at the very most, a GT500 setup should be adequate. I figure if thousands of other people can get it to work perfectly, I should be able to as well.
__________________
____________________
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
My car was doing the same thing and it turned out to be a fuel pump.I chased so many dead ends and finally it turned out to be the pump.iT WOULD ONLY DO IT AFTER BEING DRIVEN HARD ON HIGHWAY AS SOON AS YOU ENTER TRAFFIC OR SIT FOR A WHILE PEDDLE WAS LESS RESPONSIVE IT WOULD BUCK AROUND 3500RPM.But when it was cold or cooler day the car ran awesome any sort of heat and back to running crappy.i CHANGED OUT PUMP NOW it runs awesome
That sounds like the TSB where air bubbles form around the pump and cause problems after long steady use.. my problem actually starts when cold and aside from an idle issue runs fine after warming up. I did take that TSB into consideration on this, but I treated it like icing on the cake - just the thing to convince me it was a pump issue. I have had the car stall after long highway runs, but also after driving the car hard in the city. Thing is, the chances of having 2 bad pumps in a row are pretty slim. It's time to look elsewhere for the problem. I am not done with looking at the fuel delivery system, but I am finished with the pump for now.. After the electronics, I will probably start looking at evap..
__________________
____________________
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
I've thought about it, but it is very cost prohibitive. I don't intend to go over the 600 rwhp mark, even if I build the engine down the road, so at the very most, a GT500 setup should be adequate. I figure if thousands of other people can get it to work perfectly, I should be able to as well.
Must say I admire your determination! It does provide for a great sense of pride when you finally resolve it.
Mayble someone else has one lying around.
