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Hesitation under boost????

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Old 01-06-09, 06:06 PM
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Hesitation under boost????

ok a little back round. 88 gxl. series 5 j-spec turbo swap. s4 n/a comp. and harness.
under load and underboost it hesitates and back fires like a mother. i can drive the car fine out of boost but as soon as i put the pedal down it feels like it hits a wall. its like its getting to much fuel but i cant figure out the problem. this car is some much trouble but i can turn away. its like a love hate thing. i love her she hates me
Old 01-06-09, 06:15 PM
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might be a bad ground
Old 01-06-09, 06:19 PM
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how would a bad grond do that though
Old 01-06-09, 06:19 PM
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removed emissions? if so check the vacuum line on the throttle body, front and back. Change the plugs, I do it every oil change. Could also be the fuel pump failing at higher voltage.
Old 01-06-09, 06:26 PM
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emissions have been rremoved but i could have missed something( the intake mai. was off, i checked it three times but i still could have missed something), plugs and BRAND new and i will swap out my pump.
Old 01-06-09, 07:22 PM
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Did you cap and zip tie the closed line on the front and rear of the throttle body when you removed the emissions? Mine pop off under high boost sometimes.
Old 01-06-09, 07:32 PM
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That's what she said...

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It seems that you may have your timing too advance.
Old 01-06-09, 09:08 PM
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ill check those lines in the morning. cant be the timing. it was running perfect before i took the intake mani. off
Old 01-06-09, 09:20 PM
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their is also a hose that is normally like 6-8 inches long that you hook to the block, it connects to the bottom of the UIM. Its really hard to do it cause yo have to have the UIM on top of the block to connect it. I've seen a lot of people forget to connect that aswell.
Old 01-06-09, 10:04 PM
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that one is connected. i think that is the easiest one. the ones that are a pain are the three on the front behind the alt. what is the long bar the connects to the TB?
Old 01-07-09, 08:07 AM
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you have not explained your frankenstein setup fully. Is this basically an s5 shortblock with s4 wiring? either way, check TPS.
Old 01-07-09, 06:59 PM
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yes full s5 turbo swap with ALL s4 wiring
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