heres the list of mods k&N fipk, off-road h-pipe flowmaster 2.5 catback, 2.8 upper, 100mm aux idler, predator pulley tune, and boost bypass mod. Heres the problem first gear car pulls strong all the way up to 6500 rpm in first. Second gear car falls flat on its face like the bypass activates or it hits a rev limiter at around 5500 rpm anyone have any ideas. Also will the factory boost guage run past the 10 psi mark? Also I could not squeze on the 74 inch belt that is recommended with my setup is there a a trick to it I had to use the 74.5 inch belt could that be the problem.
problem after pulley swap
- Thread starter 03SilverCoupe
- Start date
ok..
- boost gauge yes it will stop at 10psi. it has a tab that stops it there, you can grind it down and use the hilton mod to read more psi.
- belt size. You are supposed to run .5" bigger when using an idler as you are, so 74.5 is the correct size.
- engine falling on its face can be alot of things, fuel? spark? etc. Try checking the plugs after a WOT run and see what they tell you. check for any vac. connections which are off etc.. GL bud!
- boost gauge yes it will stop at 10psi. it has a tab that stops it there, you can grind it down and use the hilton mod to read more psi.
- belt size. You are supposed to run .5" bigger when using an idler as you are, so 74.5 is the correct size.
- engine falling on its face can be alot of things, fuel? spark? etc. Try checking the plugs after a WOT run and see what they tell you. check for any vac. connections which are off etc.. GL bud!
i have ngk tr6s gapped at .032. If it was fuel or spark wouldnt it cause the same problem in all gears. The car pulls hard all the way to the red line in first.
Sounds like the good ol' PPRV hesitation. Does it only hesitate briefly right after the 1st to 2nd shift on hard acceleration? Try shifting faster and see if it doesn't do it...
yes it does hesitate at the first and second shift sometimes and cuts out at the 5k to 55k in second. what causes that. the redator perfomance tune didnt do that. after i installed the pulley and the pulley tune it started doing it
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if you did the manual boost bypass isnt that bad? the tune should do it shouldnt it?
im going to swap the fuel filter and see if that helps. also should I have loaded the stock tune back into the car and then load the pulley tune?
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no help with the fuel filter I guess Ill be pulling the pprv over the weekend
Sounds like the car is leaning out and detonating to me. If you value your engine I wouldn't boost it and get it on a dyno and have it diagnosed.
This would be good advice to follow. For $75 you could save your motor.
You could gap them at .035" probably and also there's no need to take the car to 6,500 rpm's because it probably hits its peak hp a lot earlier so shifting that late will actually slow the car down. You can find out your shift points or close to them by having the car on the dyno to see the graph.
I did some data logging with my predator. Im asuming that the fp percentage is the fuel pump duty cycle? under full throttle it jumps up to 50%. fuel pressure is about 60 psi but I haventy been able to measure the fuel system psi when the car fals flat on its face at 5 to 55k rpms. Im going to put the 3.0 pulley on and see what happens if there is no change whats the solution. Could the pprv be bleeding off puel pressure and making the pumps work harder? I had the shift issue even before I did the pulley swap and tune. Also could the pprv wear out my car has 130k miles on it. Either way Im going to pull the tank and take that piece of junk out
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Ill try that tonight before i go pull the tank to remove the pprv. im measuring the fpdc with a predator so actually its doubled correct it 50% to much are the pumps maxed out. Ill check the plugs right now and let you know if the plugs are black more than likely im getting spark blow out?
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Depending on how you are reading fuel pump duty cycle 50% could be 100% and that would explain your symptoms perfectly.
It sounds like one of your pumps might not "playing nice with others".
Which could be one bad or weak pump, or one of the internal hat lines perforated/split.
Or it might not be either of those and simply a clogged fuel filter.
The symptoms you are describing, to me, sounds like a problem with fuel delivery.
okay so I gapped the plugs to .025 and still the same problem. I had a friend ride with me and monitor the fuel pressure it peeked at 69 psi and then the car fell flat on its face. fuel pressure dropped to 35 to 40 psi. Isnt the pprv set to release at like 64 or 67. Im thinking that might be my problem. Even over time wouldnt that valve wear and release at lower fuel pressure?
Im going to pull the gas tank saturday and do the pprv delete. If that fixes my issue Im off to the dyno to get some a/f numbers and hp and torque. But wouldnt the pprv make sense. Im seeing 67psi at the rail and the valve is designed to relieve pressure at 64 psi?
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Have it dynoed, a/f on the dyno will spill the beans on the problem, plus all these pulls could be taking a toll on your expensive engine if your leaning out bad which it sounds like you are.
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