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Help with idle searching...already checked the common..

hosmer

Well-known member
Joined
Jan 17, 2009
Messages
121
Location
taunton, ma

..problems


Once the car warms up, its searching from 600-900 (average)...when it drops it *almost* dies but doesn't

checked for boost/vacuum leaks
pulled the (aftermarket civic size) radiator, and installed an OEM one
new radiator cap/hoses
grounded out for BISS adjustment, but it does nothing...still searches when plugs are grounded

now, if I unplug the (2g) MAF...it searches from 800-900...plug it back in and it goes back to the larger swing


setup right now is:
RS motor
20g/FP manifold
ETS i/c
550's
2g MAF on an FP 4" intake
running on a keydiver chip

The car did NOT used to do this, it idled fine with an SAFC hacked in by the PO (on the old setup...16g, OEM manifold, RS I/C, running on the chip and the SAFC which wasn't tuned at all). Unplug the SAFC and it searched but I assumed it was because of the mess at the ECU cannon plugs. So I completely re-did the plugs and I left the SAFC out afterwards as I was planning on going DSMLink

I'd love to solve this....car would pretty much be 100% if I did
 

2of9

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Joined
Aug 29, 2007
Messages
869
Location
IGH, MN
Possibly the Idle Speed Control (ISC). It's right underneath the throttlebody. Mine is also doing that.
 

prove_it

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Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
Also when you adjust the biss you need to ground both the biss adjustment screw AND the timing connector. timing will change otherwise which does effect your idle.
 

hosmer

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Joined
Jan 17, 2009
Messages
121
Location
taunton, ma

The ISC was deleted before I go the car...tried grounding the idle switch to see if that help'd but of course it didn't
 

Hertz

Staff member
Joined
Jul 29, 2002
Messages
13,501
Location
Chicago, IL
So you're trying to set the BISS to get the idle to stabilize and you don't have an ISC... you're expecting what to happen? /ubbthreads/images/graemlins/dunno.gif
 

hosmer

Well-known member
Joined
Jan 17, 2009
Messages
121
Location
taunton, ma
I'm not trying to set the BISS...I took a shot in the dark and grounded it out to see if it would help


I searched and have found NUMEROUS people who have the ISC deleted with no idle problems...I get that I have to warm the car up like I did 15 years ago with my 80-something Olds, but I don't understand why I can't get the idle to stabilize



I did NOT do this to the car...I bought it and later found the hackery under the dash...I'm just trying to save the thing, I've dumped thousands of dollars into it and hundreds of man-hours and this is the last real hurdle


Please don't assume because I just registered on this site at the beginning of this year that I'm a 17 year old kid who just got his first car and wanted something with a loud BOV to impress all my friends
 
Last edited:

hosmer

Well-known member
Joined
Jan 17, 2009
Messages
121
Location
taunton, ma
Correct...but the SAFC had no settings stored (it was a version 1 if that matters)


Do they set/adjust the idle just by wiring them in (I thought the keydiver chip would be enough to run the car as-is)?

If so, can I replicate whatever it is they do without re-installing it?
 

CarRacer

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Joined
Jun 28, 2007
Messages
4,371
Location
Shakopee, MN
Do a boost leak test after the turbo swap?
 

Rausch

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Dec 21, 2004
Messages
12,049
Location
Cleveland, OH
WAIT- ISC is gone, or just the FIAV is gone? I'm confused.
 
Last edited:

boostedinaz

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Joined
Apr 20, 2006
Messages
4,085
Location
Scottsdale, AZ
^^^^Agreed.


If the ISC is gone your idle is going to fluctuate when a load is placed on the motor. It will also have a hard time leveling out after RPMs drop a large amount.
 
Last edited:

hosmer

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Joined
Jan 17, 2009
Messages
121
Location
taunton, ma
It's not a boost leak. The car did the exact same thing on the old setup when I unplugged the safc. I assumed the problem was in the squirrels nest of a harness at the ecu.


As I said before, the car idled fine with the safc installed...but the safc had no values stored in any of the feilds. It did at one point but lost everything after sitting for a while with no battery in the car, everything was reset to default but the car still held a solid idle.

I'm trying to figure out what the safc did to steady the idle and a way I can reproduce those results without the controller




If nothing else, I'll just reinstall the damn thing this weekend
 

turbowop

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Joined
Apr 29, 2001
Messages
11,971
Location
Yakima, WA
I don't understand how the idle is surging without an ISC? The ISC is what causes idle surge by trying to adjust idle when things are out of whack, like a misadjusted BISS, or a bad FIAV, etc.
 

grocery_getter

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Joined
Jun 20, 2004
Messages
1,225
Location
Kent - industrial suburbs of Seattle, WA
Not to look down on what you already know, but...

When you take out the SAFC from the harness, did you reconnect the 2 halves of the air flow wire? When installing the SAFC, this wire has to be cut in half and then the different ends of the wire have to connected to 2 different leads from the SAFC. Basically air flow signal into the SAFC and air flow signal out of the SAFC. I have seen a few cars where they have a problem after they disconnect the SAFC because they didn't resolder the 2 halves of the wire back together again.
 
Last edited:

grocery_getter

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Jun 20, 2004
Messages
1,225
Location
Kent - industrial suburbs of Seattle, WA
I have installed so many ISC&FIAV delete plate on cars with stock ecu and the idle is steady. About the only caveat is that I don't do it on cars with AC because of the big load that the AC compressor put on the car when the compressor is turned on. But other than that ISC delete and FIAV delete works just fine on cars with stock ECU, even with stock chip.



Quoting turbowop:
I don't understand how the idle is surging without an ISC? The ISC is what causes idle surge by trying to adjust idle when things are out of whack, like a misadjusted BISS, or a bad FIAV, etc.

 

hosmer

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Joined
Jan 17, 2009
Messages
121
Location
taunton, ma
Quoting grocery_getter:
Not to look down on what you already know, but...

When you take out the SAFC from the harness, did you reconnect the 2 halves of the air flow wire? When installing the SAFC, this wire has to be cut in half and then the different ends of the wire have to connected to 2 different leads from the SAFC. Basically air flow signal into the SAFC and air flow signal out of the SAFC. I have seen a few cars where they have a problem after they disconnect the SAFC because they didn't resolder the 2 halves of the wire back together again.




I dont have a CEL, so I *assume* I did?....but I'll double check

when I disconnect my MAF the surge goes from a 600-900ish swing to a 800-900 and I get a cel...plug it back in, the cel goes away and the big idle swing comes back
 

1qkfwd

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Joined
Sep 29, 2009
Messages
209
Location
Sun Valley, NV
Is the fiav in place stil or not? If it is then you will have to plug the plunger that bypasses air for cold idle. It wont show as a boost leak since its bypassing air from infront of the tb plate to the other side raising your idle thus making the car surge. The other thing to look at is what is your low fuel trim sitting at? If it outta wack to far one way or other it will affect your idle to the high side or low side. When it does that you are out of your target idle range that the Ecu is suppose to see. The stock target is 750 so without the isc if the car is either adding or taking away fuel its making the car idle to high or to low. When it does that the car will start surging. It can start surging if its 200-500 rpms away from its target. In order to not run the isc you have to get the idle right with the ecu. So if you get a chip with a higher target idle then you need to match that with the biss. If the screw is maxed check your fuel trims and readjust the biss as needed. Thats the joys of running the isc. If theres any kind of leaks it has a certain tolerance to keep the idle within a reasonable level to not surge. Without it you must keep everything in check on your own.

I run a Q45 on my talon there is no isc on that tb. My target idle is set at 950 so when I add fuel the rpms will go up a lil bit when they get to far away from the target it will start surging. So to cure that I would add my fuel like needed and then drop the screw down.
 

grocery_getter

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Jun 20, 2004
Messages
1,225
Location
Kent - industrial suburbs of Seattle, WA
Mark, I was agreeing with what you said. I was just posting my own experience with being able to get a steady idle without isc or fiav.


Quoting turbowop:
I think you misinterpreted what I said, Andre. I realize you can get good idle when deleting the ISC and FIAV.

 
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