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Old 11-15-2013, 07:31 PM   #1
zenki14
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redtop sr slow startup

hey guys i have a 5speed converted coupe with an sr with s15 t28, fmic, lightweight pulleys, greddy intake mani, and xs power exhaust manifold

i got two questions i just cant find the answers for the life of me
1. the car starts everytime just seems like it cranks a bit longer then it should like 4-7 seconds of cranking what could cause that?

2. im pretty sure there is a crack in the exhaust manifold since i can hear an exhaust leak around the turbo and checked all bolts to the turbo, elbow, and down pipe and the boost is set at 10 psi but only hitting about 5-6.5 psi and its not pulling very well in wot. if there is a crack in the exhaust manifold would that cause this to happen because i havent found and vacuum leaks anywhere
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Old 11-18-2013, 10:55 PM   #2
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no one knows?
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Old 11-19-2013, 12:00 PM   #3
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1. Change spark plugs, run 91 or 93 octane gas... DO NOT use octane boosters or any other kind of fuel additives.

2. Exhaust manifolds can crack/leak becuse owner didn't utilize the stabilizer bracket that goes between the 4-bolt flange and the runners to keep it from pulling on itself.

Top weld of turbo elbow will eventually fail if exhaust-to-tranny bracketing isn't used.

RE-check all of your other connections, retorque everything.

Lots of people know. The problem is that you're asking about an exhaust leak in the area of the turbo... You're on the right track- no need for you to ask.
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Old 11-22-2013, 07:11 PM   #4
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Quote:
Originally Posted by Mikester View Post
1. Change spark plugs, run 91 or 93 octane gas... DO NOT use octane boosters or any other kind of fuel additives.

2. Exhaust manifolds can crack/leak becuse owner didn't utilize the stabilizer bracket that goes between the 4-bolt flange and the runners to keep it from pulling on itself.

Top weld of turbo elbow will eventually fail if exhaust-to-tranny bracketing isn't used.

RE-check all of your other connections, retorque everything.

Lots of people know. The problem is that you're asking about an exhaust leak in the area of the turbo... You're on the right track- no need for you to ask.
This is great advice here. Also I would consider verifying timing is set right as that can affect boost and sluggishness.
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Old 11-22-2013, 07:13 PM   #5
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Quote:
Originally Posted by Mikester View Post
DO NOT use octane boosters or any other kind of fuel additives.
Can I ask why?
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Old 11-22-2013, 07:14 PM   #6
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Can I ask why?
Seems to cook the plugs in sr motors they don't like additives.
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Old 11-22-2013, 07:59 PM   #7
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Do you have a fuel pressure Guage your fuel pump might be leaking gas back into the tank making the car re pressurize the system every time it's restarted

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Old 11-25-2013, 02:56 PM   #8
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Originally Posted by Dublj View Post
Do you have a fuel pressure Guage your fuel pump might be leaking gas back into the tank making the car re pressurize the system every time it's restarted

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Fuel pressure naturally bleeds off between starts- it doesn't stay under pressure for longer than a few mins when shut down. The unused fuel will follow the path of least resistance- back into the tank

Going back to the original question, verify your 4-bolt turbo flange has all 4 bolts and is properly torqued/sealed... This area above all will result in a pretty nasty exhaust leak; as well as an inability to generate the desired amount of boost.
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Old 11-25-2013, 10:10 PM   #9
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Orange wire at the ECU needs to see action during cranking.
Its called the "start signal wire", and is a common cause of slow starts.


Quote:
"Top weld of turbo elbow will eventually fail if exhaust-to-tranny bracketing isn't used."
LOL at this, I've had this happen running open downpipe. 2 Hours in the dark and an hour "fixing" a cast S15 elbow to take it's place. Cast iron elbow shouldn't fail. Experience ftw!
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