HCI done! How do I get the car to idle right??

pleasehelp

New Member

Mar 11, 2003

686

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Poplar Grove, Il

Jun 13, 2005

#1

• Jun 13, 2005

• #1

The things that were done to the car recently were: trickflow hci kit(so it has tw heads and stage 1 cam), 75mm pro m maf, 24lbs injectors(yes they match the maf), accufab 75mm fox style throttle body(elbow was deleted), egr and smog were deleted, asp underdrive pullies, mac longtube headers and pro chamber midpipe, new o2 sensors and 180 degree thermostat.
The transmission was swap for a tko unit along with new clutch, lightweight flywheel and aluminum driveshaft.
I replaced the fuel pump to a 255lph unit along with a fuel filter last year and balancer too. The wires were replaced a long with cap and rotor last year. The mechanic also changed the plugs.


The mechanic set the timing at 12 degrees and fp at 38 and made sure everythings else was working right with no vacuum leaks and said that the idle is the pcm not liking the cam. When I was driving it didn't seem to hesitate or buck when it was on load, it's just when it's idling that it fluctuates up and down and has a hanging idle(when the clutch is push the rpms stay where they were at for a couple seconds then they come down and wants to die).


I do not have any sort tuning device on the car at all. That's why I was hoping someone could help me out with just getting the car to idle right. Thanks.

 

super302

I'd do anything for free Bapples

May 29, 2004

2,878

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Davenport, IA

Jun 13, 2005

#2

• Jun 13, 2005

• #2

well....congrats on getting it all together

good luck with the idle

 

final5-0

Mustang Master

Apr 6, 2003

6,817

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79

DFW Texas

Jun 13, 2005

#3

• Jun 13, 2005

• #3

pleasehelp said:

I do not have any sort tuning device on the car at all. That's why I was hoping someone could help me out with just getting the car to idle right. Thanks.

Click to expand...

Your not the first to say that, lol.

Welcome to the world of idle woes after the old h/c/i upgrade.

Your mechanic is right about the pcm not being happy with what all you just got through doing.

You can always drive it for a few days to see how much that same pcm will adapt to those changes. Maybe it will be enough for you to be satisfied.

Sometimes you can do things to help the idle like:
clock the maf one way or the other
use the throttle blade stop screw to increase the idle speed
play around with the fuel pressure

If you search on ANY forum like this one or even tuner forums you'll quickly find a stable idle with mods such as yours is a topic that is always asked about.

If you have no luck with mechanical adjustments you'll have to learn to live with it or go for a custom tune.

Later
Grady

 

mootang

New Member

Dec 5, 2004

907

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texas

Jun 14, 2005

#4

• Jun 14, 2005

• #4

I used the throttle screw and turned the idle speed up so it idles at about 1k and It doesn't stall once i drive but when i first start the car up it will idle fine for about 30 seconds and then it will start freeking out and stall. but like i said once I start to drive it will idle at about 1k when i come to a stop.

I'm getting tired of not being able to let my car warm up with out giving it gas to keep it from stalling so my next mod will be a dyno tune.

good luck

 

91LX_5L

Founding Member

May 13, 2002

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36

British Columbia

Jun 14, 2005

#5

• Jun 14, 2005

• #5

Tweecer.

try these first

http://www.muscularmustangs.com/maintain.html

 

cavscout371

New Member

Mar 30, 2005

277

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0

Jun 14, 2005

#6

• Jun 14, 2005

• #6

I just have mine idling high for now 1000-1100 till I get a tune

 

zenboy99

Founding Member

May 12, 2002

2,212

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47

Madison, WI

Jun 14, 2005

#7

• Jun 14, 2005

• #7

I went with a JMS chip for $325 shipped. Car idled perfect when I first put it in without a hanging idle or stalling. I was very pleased.

 

rio95

Member

Nov 18, 2003

829

1

17

Grand Rapids, MI

Jun 14, 2005

#8

• Jun 14, 2005

• #8

I highly doubt you can get away w/o a dyno tune or mail order chip. Have you tried to bump the idle up first with the set screw?

 

94-302-vert

Active Member

Aug 16, 2004

1,947

2

36

NE CT

Jun 14, 2005

#9

• Jun 14, 2005

• #9

bud of mine had the same problem. it turned out that one of his injectors was stuck open. had then cleaned and a replacement for the bad one put in place.

 

1slow95

Founding Member

May 16, 2002

1,797

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48

ohio

Jun 14, 2005

#10

• Jun 14, 2005

• #10

Mine idles fine at around 1000 RPM's with no tuning. It does surge a little at times, but not enough to stall. I say just turn the idle screw up until it's idling high enough that it doesn't surge, until you can get a dyno tune or chip.

 

final5-0

Mustang Master

Apr 6, 2003

6,817

12

79

DFW Texas

Jun 14, 2005

#11

• Jun 14, 2005

• #11

All these things we tell pleasehelp to try are great and I think hes got nothing to loose by trying them.

however..............

When it comes to h/c/i idle gremlins and other drivability issues.

IMHO, this fact remains.............

Just cause one of these ideas works on one combo you could have another combo exactly like it and it can act totally different.

pleasehelp, I hope some of this stuff works for you.

Later
Grady

 

J

Jack's95gt

Member

Aug 15, 2004

443

1

18

Huntingdon Valley, PA

Jun 14, 2005

#12

• Jun 14, 2005

• #12

I kept my car running after the HCI with a idle air bypass kit. It still had a hanging idle with it, but it was running without stalling. Now I'm playing around with a tweecer and may get some wideband 02's.

 

RIO5.0

15 Year Member

Feb 16, 2001

6,892

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128

N.H.

Jun 14, 2005

#13

• Jun 14, 2005

• #13

As Grady said...the combo's can all re-act different....The Fox thing gave me surging after the first day...at first I ran it all Summer with the IAC unplugged...Surge/hunting gone...It was a temp fix only....once the cold weather hit it was back...I had to fix it....mine was hanging idle bigtime whenever I connected the IAC valve...

I did the full idle re-set in the link posted above...That cured mine....My idle is only set to maybe 700 or prolly less...its pretty low...

Mine was set last Summer and is acting up again...I'm gonna do the full idle re-set again...I guess adaptive strategy came back... :damnit: Price we pay for playing with em... I have so many different parts in there and stuff removed i really can't complain...Other than having to hold the idle for 20 secs or so on an occasional start-up, mines fine...
Just part of the tuning process with an upgrades that you did...

 

H

harley02

New Member

Aug 29, 2004

110

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Tarpon Springs, FL

Jun 15, 2005

#14

• Jun 15, 2005

• #14

This is the reason I want to stick w/a stock cam when the next engine is built. Dont have the time or experience w/tweecers or chips. Hopefully the S/C will take care of the HP woes. Yeah, I know I could get more HP w/a different cam, but I dont want major tuning issues.

 

final5-0

Mustang Master

Apr 6, 2003

6,817

12

79

DFW Texas

Jun 15, 2005

#15

• Jun 15, 2005

• #15

harley02 said:

This is the reason I want to stick w/a stock cam when the next engine is built. Dont have the time or experience w/tweecers or chips. Hopefully the S/C will take care of the HP woes. Yeah, I know I could get more HP w/a different cam, but I dont want major tuning issues.

Click to expand...

A blower can cause you to need or at least want some help with a custom tune even if you use the stock cam.

All the extra air flow it causes kinda hoses around with your stock load values in the pcm. This is just one of the things a blower can throw off in your tune and there are others to be sure, but this one of the biggies.

Threads like this one...made me see it...kinda sorta like this

Might not wanna embrace it............

but

You might as well face it................

You can only go so far with your quest for more performance until you need some help in the tuning department beyond twisting the dizzy & an afpr.

Later
Grady