Jware93

Hey guys, question for the team. I have a 2008 IS-F. It has been so slow on take off. I went to the 1/8th drag strip and was getting best by g37s with some bolt ons. Which that shouldn't happen. I have a custom intake with afe filter, sikky headers, throttle controller, cat delete, custom exhaust with bullet mufflers. When I ran I was getting 9.1s consecutively with 60' being about 2.3.
The car has been dyno'd and claims to be making about 357 give or take to the wheels and 353tq. I have cleaned the throttle body, used fuel injection cleaner. Changed the intake filter. I'm being told I should atleast be around 390 or so to the wheels. I'm still fairly new to the isf as I've only owned it for a few months. I've checked for vacuum leaks none to be bored as I can see. Is there any other recommendations that anyone can give for me to check. I'm wondering if it could be a fuel pump related issue.

Thanks guys

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Helo58

Let's begin with the obvious questions to get them out of the way. What tires and wheels? Was traction control off? A 2.3 60' time seems really high. I only have a borla exhaust with stock everything else and Bridgestone S-04's (stock sizes) and can cut a 2.0 60' with ease and a 1.8 in ideal conditions.

Jware93

Axis shine wheels not really heavy, 255/35/19 toyo proxes 4 plus they hooked up great, traction was fully disabled with sport mode and throttle controller on.

Joker4096

iTrader: (2)

Maybe reset your ecu so it can relearn a higher KCLV setting. I have friends that work at the dealership and many cars come in for hesitation. they reset the memory module and have it relearn the settings.

Jware93

I left the battery unplugged this morning for a good hour and still not better even after cleaning the TB

Joker4096

iTrader: (2)

Do you have an air/oil separator?

Jware93

No sir I do not

Helo58

What type of air filter are you running, dry or oiled? Have you cleaned the Mass Flow sensor?

Jware93

Afe dry filter and yes it's been cleaned

Scott610

iTrader: (3)

What i think is that u must have a vaccuum leak somewhere and do u have a cel ? Try doing a smog test

Jware93

No cel hmm I haven't tried a smog test

Helo58

Have you eliminated all of the other "easy" variables such as: quality of gas, reasons for engine to "pull" timing, proper functioning of the throttle controller? Is your exhaust really sooty? Does the car reach high rpm smoothly and repeatedly (even if slowly)?

Jware93

Yes I use bp or shell all the times, all the others you stated are good and yes I got the functioning of the throttle controller, exhaust isn't really sooty. It reaches high rpm fine

Helo58

The symptoms of a bad fuel pump are irregular idle, hard starting, but most importantly in your case, an inability to "keep up" at higher rpm. If you are not having a sputtering, missing, etc. at high rpm, it would look less likely to be a fuel pump issue. If all of the easy fixes are good, then I'd look at the next level. What is your mileage? How are your spark plugs? Many reported drastically improved performance on replacing high mileage plugs. Are all of your intake connections secure and leak free? Do you have the ability to read engine parameters (techstream, torque, etc.)? Does the potential exist for a brake to be dragging? Do you have a friend from the forum with an ISF that could ride along with you to help you troubleshoot?

Scott610

iTrader: (3)

For me I think it's wierd that the car does not have a cel when my o8 isf was running sluggish found out that it was a vacuum leak from my oil catch can screw make Shure all your screws and clamps are tight the smallest hole would cuz a problem good luck