2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Major hesitation when boosting

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Old Aug 17, 2004 | 02:50 PM
  #1  
LowFreq's Avatar
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From: boston, ma
Major hesitation when boosting

On Saturday I installed 720cc secondaries. Took it for a 10 min run to test it out, no problems while driving. Got back to the house, and noticed that I was leaking some antifreeze from under the intake.
So I let it sit for a coupla days and today i pulled the intercooler off and tightened up the clamp on the hose under the intake. Took it for another 5 min run and noticed that there's major hesitation when it boosts. If I keep it out of boost it drives normal all the way thru the rpm band, but if I give it gas and boost it, then it hesitates.
I've got an SAFC installed that I haven't tuned yet.
My first thought was that since the SAFC isn't tuned, once the secondaries come on, it's flooding the engine with too much fuel, but it was running fine Saturday. Also, the secondaries come on whether you're boosting or not.
Then I thought--maybe a vacuum leak--but it idles fine.

Any ideas?
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Old Aug 17, 2004 | 03:20 PM
  #2  
Boost Lee's Avatar
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From: Tacoma WA
Uhh... you're dead on. You're running way rich when those secondaries come in.
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Old Aug 17, 2004 | 04:21 PM
  #3  
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From: Kansas City
I'm having the same problem with my AE..its funny we are running similar setups. What kinda hybrid are you running?
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Old Aug 18, 2004 | 04:42 PM
  #4  
LowFreq's Avatar
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From: boston, ma
Originally Posted by Arpus
Uhh... you're dead on. You're running way rich when those secondaries come in.
One of the clamps on the turbo to IC hose was bad. It only gave under boost which is why it idled fine.
I like those kinds of fixes.
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Old Oct 24, 2004 | 10:00 PM
  #5  
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From: Co springs, co
hmmm thats is the EXACT problem that i have except i dont have 720's thoughs come soon.... so if you say you get a hesitation is around the 2400-4000rpm range? i have the apexi safc gen 1 and i think that it gets to rich around the 2500~ish range. so i get a hesitation every once in a while. it works through it though which is why dont think its anything major. its seems to change when i adjust either dial
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Old Oct 24, 2004 | 11:50 PM
  #6  
RETed's Avatar
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From: n
Originally Posted by LowFreq
I've got an SAFC installed that I haven't tuned yet.
And you're asking us what the problem is???


-Ted
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Old Oct 24, 2004 | 11:58 PM
  #7  
ilike2eatricers's Avatar
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From: bay area
I dont think it's the injectors. I run 720 secondaries untuned and the car drives fine. Rich I bet but not so bad it stumbles or hesitates noticably. I think it's a intake leak that only is noticable during boost.
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Old Oct 25, 2004 | 01:55 AM
  #8  
DC350's Avatar
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From: British Columbia
its the s-afc man.... i have 720's s-afc and is also untuned. Car runs to rich, robs power.

Get it tuned i need to as well...
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Old Oct 25, 2004 | 02:39 AM
  #9  
NZConvertible's Avatar
I'm a boost creep...
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From: Auckland, New Zealand
At the very least you need to set all the corrections over 3800rpm to -13% to get your mixtures back to normal.
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