I cannot figure out what's wrong with my car for the life of me. I changed out the spark plugs fuel filter etc.. still the car won't run faster than 13.6 with a 2.0 60ft. Only trapping around 80mph in the 1/8. Car has Mina intake and pulley, x-pipe and magnaflow mufflers. Also the 3in intake pipe. Long term Fuel trims are out of wack also 10.5 and 12.4. I tried spraying carb cleaner everywhere to find the leak but there was never a change in idle. Couldn't find a leaky hose anywhere the PVC makes a hissing noise but I think that's normal. Anybody has any suggestions? Car has almost 100k miles

 

If the trims head much nearer 0 when revved then yes you have a leak. They can be awkward to find as there are so many places it could be and the engine bay is full. Have you kept the factory-type plugs?

 

Yea the ngk iridums. The car actually had ngk laser iridum plugs in when I replaced them, that looked pretty good still.

 

Well 13.6 is not bad depending on your altitude. What's the elevation of the track you run at?

Have you tried correcting the time back to sea level to see what it would run there? It's not exact but might give you an idea?

You don't have your car details but the early 2003-2004 STR's had a bad short shifting problem. During one of the early road test's the car only ran a 14.1!!

Are you getting to redline in all gears especially 1st and 2nd?
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About to cause trouble but....... Can grade and make of fuel make a difference? Air filter?

 

You might also consider putting the stock intake back on and doing a couple runs.

The few aftermarket items we have are poorly documented and people have lost power when messing with the intake.
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Find and fix any air leak is my take on it.

 

Mine had an air leak from the brake vacuum line to the master cylinder(something like that). This caused a bit I hesitation and loss if power only under load in the overdrive gears and no codes, but the jag scanner showed a lean code on one bank. The way the tech diagnose it was putting a smoker device in my intake tube and looked or leaks. They nailed I immediately so I would do the same and get it hooked up to a proper jag scanner.

 

Yea that's what I'm thinking. I'm going to try the cigar method. I wanted to do a boost leak style test like I would on Dsm's in the past.

 

what did you mph in the 1/4?

 

Around here, a 13.6 is a fantastic time. Then again, the DA is usually ~8000 ft.

 

102mph. Last time I went I was trapping 104 consistanly. For a second i thought it maybe was my ic pump. I did 2 runs back to back and the mph didn't change.

 

What Did you change since running the 104? Wonder if that open element filter is slowing you down... Do you have the intake tube done too or stock?

 

I've always had the intake tube and filter. First mod I did. And only change was the new plugs and fuel filter. And a little bit more gas.