LSX Intake & TB - Surge/Idling Issues ?
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Joined: Dec 2001
Posts: 601
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From: Texas
LSX Intake & TB - Surge/Idling Issues ? I recently installed the LSX intake/TB a month or so ago and I'm experiencing some erratic idle issues. The car turns over no problem, however I have to apply minor throttle to keep it running (else it turns over and immediately dies when cold). After about 30 seconds the car seems to idle (DIS=800; LS1edit) fine. Now here's the problem (erratic), when I begin driving and I approach a stop the car begins to surge between 400-1100 rpm until it stalls. Now what I've been doing is performing the idle re-learn which seems to hold for a little while but I really have to stop slowly at lights/stop signs or it intermittenly stalls again. Of course once it stalls and is restarted its really pissed and requires another idle relearn.
I haven't had a chance to have it re-tuned but is this really a tuning issue ? Is it possible the IAC is bad (car only has 9000 miles on it) ? When I installed the TB I verified that the blade completely closes so any ideas would be appreciated.
Thanks....
Here's a list of the setup:
A4
AS Stage 1x 5.7ltr Heads milled .030
TR224 563 on a 114
Nate's Billet Fuel Rails
Stock Injectors
78mm LSX Intake
78mm LSX TB
I haven't had a chance to have it re-tuned but is this really a tuning issue ? Is it possible the IAC is bad (car only has 9000 miles on it) ? When I installed the TB I verified that the blade completely closes so any ideas would be appreciated.
Thanks....
Here's a list of the setup:
A4
AS Stage 1x 5.7ltr Heads milled .030
TR224 563 on a 114
Nate's Billet Fuel Rails
Stock Injectors
78mm LSX Intake
78mm LSX TB
https://ls1tech.com/forums/showpost....9&postcount=28
Check this post out. Mine was doing that too. 90mm TB and LSX intake.
Check these mechanical things first for binding or that loose bearing. Then check your IAC counts and yes check for vacuum leaks. After all that then get her tuned.
Check this post out. Mine was doing that too. 90mm TB and LSX intake.
Check these mechanical things first for binding or that loose bearing. Then check your IAC counts and yes check for vacuum leaks. After all that then get her tuned.
Thread Starter
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Joined: Dec 2001
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From: Texas
Thanks to those that replied... I'm pretty positive its not a leak since all the seals are new and all the bolts were torqued to spec and later checked again.
Dustin Butts : I'll check the mechanical and the reading on the IAC, a big thanks for posting the link and excellent write-up. I'll post back my results tomorrow.
Andy
Dustin Butts : I'll check the mechanical and the reading on the IAC, a big thanks for posting the link and excellent write-up. I'll post back my results tomorrow.
Andy
Thread Starter
TECH Enthusiast
Joined: Dec 2001
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From: Texas
Ok, I pulled some stored data runs (idle) I had sitting on my laptop - before and after the LSX intake/TB. My IACP (idle air controller position) counts are as follows:
Before LSX Intake/TB:
range is 22-30
After LSX Intake/TB:
range is 89-95
So whats causing the counts to read higher ?
Before LSX Intake/TB:
range is 22-30
After LSX Intake/TB:
range is 89-95
So whats causing the counts to read higher ?
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Stock TB and Intake does the same thing after cam install. Mine does the exact same thing since my cam was installed. Crank at first and idels at 1000-1200 rpm and then after about 10 seconds, it drops down to 700 rpm and surges real bad. It dies once or twice ... only does it on cold starts and at stopsigns and stoplights.
Before my cam install, on cold starts, it wouldn't surge at all, however, it would choke down like it was going to stop running when I'd pull out ... only for about 5 seconds, then, it would run fine.
I changed my fuel filter and injectors and it didn't seem to help much, if any at all ... for what it's worth. It would be nice to know what this is. Think it would help to drill out the throttle plate a little bigger than the factory hole?
Before my cam install, on cold starts, it wouldn't surge at all, however, it would choke down like it was going to stop running when I'd pull out ... only for about 5 seconds, then, it would run fine.
I changed my fuel filter and injectors and it didn't seem to help much, if any at all ... for what it's worth. It would be nice to know what this is. Think it would help to drill out the throttle plate a little bigger than the factory hole?
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TECH Enthusiast
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From: Texas
Didnt get a chance to test anything today, guess it will have to wait till the weekend.
Thanks Ragtop for the explanation of high/low IAC counts, I searched and couldn't find an explanation...
JEB99TA, has your car ever been tuned via LS1edit ?
Thanks Ragtop for the explanation of high/low IAC counts, I searched and couldn't find an explanation...
JEB99TA, has your car ever been tuned via LS1edit ?
It's been dyno tuned It was dyno tuned when the cam was installed. The tuner said that he changed one of the tables that should either fix the problem or at least make it better. He told me if it didn't totally go away, he would change the same table, which hopefully would fix it. After it did not help and after my max RWHP/PWTQ numbers fell each time it was tweaked/dyno'd, well, I decided not to go back and have it 'tweaked' anymore.
Since he changed whatever he changed and there was no difference, it doesn't seem to be a tuning problem. The !EGR and !AIR were both removed and disabled by the tuner.
Since he changed whatever he changed and there was no difference, it doesn't seem to be a tuning problem. The !EGR and !AIR were both removed and disabled by the tuner.
Launching!
Joined: Mar 2003
Posts: 262
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From: Kuwait / USA
i am having the same problem with my Solid roller. the car have been built and tuned by Allen Futral. but the same problem, we couldnt fix it. Allan told me straight out, the fast throttle body is piece of ****. the car is been shiped overseas as we speak, but is there a way to fix it when i get it. i dont want to spend another ~$500 on something that doesnt work
Originally Posted by Solid346
i am having the same problem with my Solid roller. the car have been built and tuned by Allen Futral. but the same problem, we couldnt fix it. Allan told me straight out, the fast throttle body is piece of ****. the car is been shiped overseas as we speak, but is there a way to fix it when i get it. i dont want to spend another ~$500 on something that doesnt work
