Surging idle after "the" big install.

1FastSTi · 01-17-2006, 03:37 PM

I fired the car up for the first time after installing the following:

SZ55
PE 850's
Perrin turbo inlet
Perrin FMIC
Perrin EBCS

The car started up instantly no problems what so ever. I still have the stock pump on just to get it running. The car runs fine until it comes up to temperature. I have an appointment to get it tuned, is this something the tuner will work out or is there something else I can check out myself. Could it have anything to do with the injector scale? I forgot to check the correction factor on the dashboard so that may be it, any other suggestions?

WolfPlayer · 01-18-2006, 04:31 AM

When the car comes up to temp the idle usually drops down. Thus, fluctuations are a little easier noticed. Did you remove the intake manifold at all? This could be a slight vacuum leak.

t

1FastSTi · 01-18-2006, 04:59 AM

Quote:

Originally Posted by WolfPlayer

When the car comes up to temp the idle usually drops down. Thus, fluctuations are a little easier noticed. Did you remove the intake manifold at all? This could be a slight vacuum leak.

t

The intake manifold was kept intact. All hose clamps and vaccum lines have been gone over. I might add that the car stumbles when any throttle is applied. Im going to try and play around with the injector scale as soon as I get some time.

WolfPlayer · 01-18-2006, 06:18 AM

FWIW, most PE850 setups I have seen have the latency values cut in half.

t

**Siegel Racing** · 01-18-2006, 06:50 AM

The full PE injector latency by voltage table is published on here somewhere... If you set the injector sizing and latency correct it should idle pretty well.

SS

1FastSTi · 01-18-2006, 12:51 PM

Thanks guys, I can't seem to find that table anywhere though. If anyone runs into it please post it!

1FastSTi · 01-18-2006, 01:17 PM

Ok so I went out and messed with the injector scale for like 10mins or so and changed it from 3065 to 3590. The A/F Trim was fluctuating from -2.75 to about 3.50 or so. The car still surges ever 10 secs or so but it is much smoother now. Its still not perfect which I want it to be but its a starting point.

Defiantspaz · 01-18-2006, 01:25 PM

I have the same injectors and Tony at XX Tuning was able to tune my Cobb AP so it would idle smoothly. Your tuner should be able to do the same for you.

Nice set-up, post some numbers when it gets tuned.

AdamBlitzer · 01-18-2006, 02:11 PM

i am sure you did this.. but didn't see in your list.. did you do TGV deletes.. i believe you have to...

1FastSTi · 01-18-2006, 02:14 PM

Quote:

Originally Posted by AdamBlitzer

i am sure you did this.. but didn't see in your list.. did you do TGV deletes.. i believe you have to...

No, they are still in place. However I don't see any reason they would cause any problems.

aspensti05 · 01-18-2006, 02:46 PM

TGV deletes have nothing to do with this.

I have the same turbo AND the same injectors AND Tony from XX tuning tuned my car AND I have the same idle problem that 1FastSti has.

Defiantspaz · 01-18-2006, 03:48 PM

I had it aswell with the UTEC. When Tony retuned my car with the Cobb AP on Tuesday he manged to get the car to smooth out and idle fine. Aspen when you go in on the 28th he can probable get your car to idle smooth aswell.

Good luck with your tune by the way.

aspensti05 · 01-18-2006, 04:10 PM

That was the plan...fix idle/other drivability issues and retune for APS DR725.

Thanks for the well wishes. I'llbe very happy if I make numbers like yours!

1FastSTi · 01-18-2006, 06:03 PM

Quote:

Originally Posted by aspensti05

That was the plan...fix idle/other drivability issues and retune for APS DR725.

Thanks for the well wishes. I'llbe very happy if I make numbers like yours!

What other drivability issues were/are you having so I know what else I can expect. I hope I only have to make one trip to the tuner to get everything ironed out. I kinda doubt that will happen though.

Defiantspaz · 01-18-2006, 06:15 PM

If you are driving at a steady pace and then lightly back off the trottle sometimes my car would shutter violently back and forth, kinda like bucking on a start only it is at 75MPH. Bad Idle, poor fuel milage and the shutter were all of the issues that I had. Switching to the Cobb AP has so far solved all of these drivability problems for me.

01-17-2006, 03:37 PM	#1
1FastSTi Junior STI Driver Car: 04 STi Location: Mohnton (Berks County) Pa Posts: 131 Join Date: Apr 2004 Trader Rating: (0)	Surging idle after "the" big install. I fired the car up for the first time after installing the following: SZ55 PE 850's Perrin turbo inlet Perrin FMIC Perrin EBCS The car started up instantly no problems what so ever. I still have the stock pump on just to get it running. The car runs fine until it comes up to temperature. I have an appointment to get it tuned, is this something the tuner will work out or is there something else I can check out myself. Could it have anything to do with the injector scale? I forgot to check the correction factor on the dashboard so that may be it, any other suggestions? This ad is not endorsed by this member. Please register or login to hide this ad.

01-18-2006, 06:15 PM	#15
Defiantspaz Silver Member Car: 04 WR Blue Pearl STI Fav Mod: Ultimate Racing twin-scroll GT4094R! Location: CT Posts: 235 Join Date: Mar 2005 Trader Rating: (0)	If you are driving at a steady pace and then lightly back off the trottle sometimes my car would shutter violently back and forth, kinda like bucking on a start only it is at 75MPH. Bad Idle, poor fuel milage and the shutter were all of the issues that I had. Switching to the Cobb AP has so far solved all of these drivability problems for me. This ad is not endorsed by this member. Please register or login to hide this ad.

01-18-2006, 04:31 AM	#2
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,703 Join Date: Jun 2004 Trader Rating: (6)	When the car comes up to temp the idle usually drops down. Thus, fluctuations are a little easier noticed. Did you remove the intake manifold at all? This could be a slight vacuum leak. t

01-18-2006, 06:18 AM	#4
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,703 Join Date: Jun 2004 Trader Rating: (6)	FWIW, most PE850 setups I have seen have the latency values cut in half. t

01-18-2006, 06:50 AM	#5
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,262 Join Date: Mar 2005 Trader Rating: (2)	The full PE injector latency by voltage table is published on here somewhere... If you set the injector sizing and latency correct it should idle pretty well. SS

01-18-2006, 12:51 PM	#6
1FastSTi Junior STI Driver Car: 04 STi Location: Mohnton (Berks County) Pa Posts: 131 Join Date: Apr 2004 Trader Rating: (0)	Thanks guys, I can't seem to find that table anywhere though. If anyone runs into it please post it!

01-18-2006, 01:17 PM	#7
1FastSTi Junior STI Driver Car: 04 STi Location: Mohnton (Berks County) Pa Posts: 131 Join Date: Apr 2004 Trader Rating: (0)	Ok so I went out and messed with the injector scale for like 10mins or so and changed it from 3065 to 3590. The A/F Trim was fluctuating from -2.75 to about 3.50 or so. The car still surges ever 10 secs or so but it is much smoother now. Its still not perfect which I want it to be but its a starting point.

01-18-2006, 01:25 PM	#8
Defiantspaz Silver Member Car: 04 WR Blue Pearl STI Fav Mod: Ultimate Racing twin-scroll GT4094R! Location: CT Posts: 235 Join Date: Mar 2005 Trader Rating: (0)	I have the same injectors and Tony at XX Tuning was able to tune my Cobb AP so it would idle smoothly. Your tuner should be able to do the same for you. Nice set-up, post some numbers when it gets tuned.

01-18-2006, 02:11 PM	#9
AdamBlitzer Spec C Club Posts: 1,109 Join Date: Jan 2005 Trader Rating: (3)	i am sure you did this.. but didn't see in your list.. did you do TGV deletes.. i believe you have to...

01-18-2006, 02:46 PM	#11
aspensti05 Spec C Club Car: BMW M5 993 Turbo Location: Southwestern, CT Posts: 1,293 Join Date: Sep 2005 Trader Rating: (5)	TGV deletes have nothing to do with this. I have the same turbo AND the same injectors AND Tony from XX tuning tuned my car AND I have the same idle problem that 1FastSti has.

01-18-2006, 03:48 PM	#12
Defiantspaz Silver Member Car: 04 WR Blue Pearl STI Fav Mod: Ultimate Racing twin-scroll GT4094R! Location: CT Posts: 235 Join Date: Mar 2005 Trader Rating: (0)	I had it aswell with the UTEC. When Tony retuned my car with the Cobb AP on Tuesday he manged to get the car to smooth out and idle fine. Aspen when you go in on the 28th he can probable get your car to idle smooth aswell. Good luck with your tune by the way.

01-18-2006, 04:10 PM	#13
aspensti05 Spec C Club Car: BMW M5 993 Turbo Location: Southwestern, CT Posts: 1,293 Join Date: Sep 2005 Trader Rating: (5)	That was the plan...fix idle/other drivability issues and retune for APS DR725. Thanks for the well wishes. I'llbe very happy if I make numbers like yours!