car will not launch and is trapping very very low????
05-30-2009, 07:35 PM
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Staging Lane
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car will not launch and is trapping very very low???? ok so i have a 230/230 600 lift cam, ls6 intake, headers, true duals, 9inch, 3200 stall, torque arm and relocation bracket and 26x11.5 15lt hoosiers. when the car was cam only with no bolt-ons it went 7.9 at 88mph with a 1.89 60ft (all this is 1/8th mile) with crappy tires. since then i have added the above listed parts and picked up around 60 hp on the dyno.
the car has felt strong lately so i took it to the track last night. when we get their the car is trying to die at an idle and running kinda rough (after about an hour drive) i decided to try a run and when i launched the car fell on its face it pulled a 2.0 60ft. then it just felt rough the rest of the way down the track. it ran a 8.3 at 84mh.
i tried a few more passes and all ended the same. on the drive home the car would feel like it would miss out at times, and was idling rough.
before i went to the track i installed a K@N filter because mine was bad, then i found out it had just been recharged. so i was thinking the mass airflow sensor got dirty. so i bought mass airflow sensor cleaner and sprayed it off (slp mass airflow sensor). i took the car out after it sat for awhile and it didn't feel any better.
i am lost what do you think it could be. i think the car should run mid 7s at low 90s with a 1.75 60ft. i am getting frustrated please help!!
the car has felt strong lately so i took it to the track last night. when we get their the car is trying to die at an idle and running kinda rough (after about an hour drive) i decided to try a run and when i launched the car fell on its face it pulled a 2.0 60ft. then it just felt rough the rest of the way down the track. it ran a 8.3 at 84mh.
i tried a few more passes and all ended the same. on the drive home the car would feel like it would miss out at times, and was idling rough. before i went to the track i installed a K@N filter because mine was bad, then i found out it had just been recharged. so i was thinking the mass airflow sensor got dirty. so i bought mass airflow sensor cleaner and sprayed it off (slp mass airflow sensor). i took the car out after it sat for awhile and it didn't feel any better.
i am lost what do you think it could be. i think the car should run mid 7s at low 90s with a 1.75 60ft. i am getting frustrated please help!!
05-30-2009, 08:58 PM
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Hello, don't take this the wrong way ( I might have missed something) but you picked up 60 rwhp from a LS6 intake and exhaust?
I think you were headed in the right direction tho with your troubleshooting logic. Car picked up power on the dyno and all you did was change the airfilter and now it is running like dookie-that would lead me to an over oiled filter fouling out a MAF sensor. Was the K & N brand new (with no extra "special sauce")?
Do you have access to a known good stock MAF?
I think you were headed in the right direction tho with your troubleshooting logic. Car picked up power on the dyno and all you did was change the airfilter and now it is running like dookie-that would lead me to an over oiled filter fouling out a MAF sensor. Was the K & N brand new (with no extra "special sauce")?
Do you have access to a known good stock MAF?
05-30-2009, 09:26 PM
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Hello, don't take this the wrong way ( I might have missed something) but you picked up 60 rwhp from a LS6 intake and exhaust?
I think you were headed in the right direction tho with your troubleshooting logic. Car picked up power on the dyno and all you did was change the airfilter and now it is running like dookie-that would lead me to an over oiled filter fouling out a MAF sensor. Was the K & N brand new (with no extra "special sauce")?
Do you have access to a known good stock MAF?
I think you were headed in the right direction tho with your troubleshooting logic. Car picked up power on the dyno and all you did was change the airfilter and now it is running like dookie-that would lead me to an over oiled filter fouling out a MAF sensor. Was the K & N brand new (with no extra "special sauce")?
Do you have access to a known good stock MAF?
05-31-2009, 10:37 AM
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Staging Lane
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the k@n filter was just recharged before i installed it.
for the dyno numbers it only did around 330 the first time i added fuel pump, ls6 intake, headers, true duals, throttle body (ported mine was messed up) and it did around 390hp.
there is no ses light coming on.
i will try to borrow a stock mass airflow sensor.
thanks guys keep it coming
for the dyno numbers it only did around 330 the first time i added fuel pump, ls6 intake, headers, true duals, throttle body (ported mine was messed up) and it did around 390hp.
there is no ses light coming on.
i will try to borrow a stock mass airflow sensor.
thanks guys keep it coming
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06-15-2009, 10:19 PM
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Staging Lane
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ok i borrowed a good maf sensor from a friend and installed it, the car ran the same (like crap). but when i unplug the maf sensor the car runs better( doesn't miss or hesitate while driving). i guess the car goes into open loop when the maf is unplugged so does that mean its another sensor causing the issues?
06-15-2009, 10:29 PM
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no the car goes into SD mode when the car has the maf unplugged, still closed loop though, carful not to go above 4000 rpms as stock tunes make it go LEANNNN.
get the car tuned bro... your maf calibration is way off probly but SD tune for cammed cars is nice
get the car tuned bro... your maf calibration is way off probly but SD tune for cammed cars is nice
06-15-2009, 10:32 PM
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FormerVendor
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No, when you unplug the MAF you are in Speed Density for airflow meaurement-completely different subject from narrow band O2 trim input. Unplugging the MAF has nothing to do with Open Loop or Closed Loop fueling operation.
06-15-2009, 10:35 PM
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Staging Lane
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im lost the car has been tuned and running fine for months and all of the sudden this happens. the car i took the maf sensor from runs fine but in my car it ran like crap.
06-16-2009, 10:29 PM
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Staging Lane
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i was just saying hp numbers dont mean much, dynos are good for doing wide open throttle tuning so you dont have to do it at a track or on the street. and my lil cam car has been in the 11s on motor not great but seems ok to me.
06-17-2009, 07:08 AM
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My car did this once and it ended up being a full tank of bad gas. It took a long time for me to clear it out because I didn't drive it on the street much.
07-11-2009, 05:18 PM
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ok so i checked the fuel pressure and it is dropping to 20psi then jumping from 30psi to 15 psi but stays around 20. i have a walbro 255 that is about a year old. do you think its the regulator or the pump and is there any way to check?