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Wierd idle characteristics after lower intake install

  • Thread starter Thread starter RacEoHolic330
  • Start date Start date May 12, 2005

RacEoHolic330

I like to dress like a pretty girl
15 Year Member
Mar 4, 2003
4,014
1,698
203
Allentown, PA
May 12, 2005
#1
  • May 12, 2005
  • #1
The rear gasket on my holley lower intake was leaking oil so i tore everything down, fixed the leak, and then put everything back together. I readjusted the timing to 10* base, and checked my tps voltage. Now, when I start the engine when its cold, it will barley idle at all. It wants to keep dying unless I give it gas. My plx also reads LEAN (greater than 20:1). Once it warms up, my a/f at idle is at 14.7ish and the car will idle somewhat normally. It's still not the same as it was before. I'm pulling 2-3inHg more vacuum at idle than I was before. However, when it sits for a while idling (2-3 min)and i give it gas, it goes way rich and wants do die sometimes and is a ****** to start back up again.

I tried upping the idle. It helps to keep it idling when cold, but once it warms up it idles at like 1100 rpms. I don't understand how removing/installing my lower intake could cause all these problems. Nothing was changed on my PMS or anywhere else. I appreciate any help guys.

88 GT
vortech sq, stock pullies
anderson b-31 cam
afr 165's
holley systemax II intake manifold
42 lb injectors
255 intank, t-rex inline pump
 

Notchbck93

New Member
Dec 9, 2003
422
1
0
IL
May 12, 2005
#2
  • May 12, 2005
  • #2
Check the orange wire that grounds the 02 sensors. It goes on the back of the block, and most forget to hook it back up when they do a lower intake.
 

RacEoHolic330

I like to dress like a pretty girl
15 Year Member
Mar 4, 2003
4,014
1,698
203
Allentown, PA
May 12, 2005
#3
  • May 12, 2005
  • #3
I never needed to disconnect that wire. As you said, its on the back of the block. It didn't interfere with the removal of the lower intake.
 
L

LQQKIN4COUPE

New Member
Feb 8, 2004
41
0
0
May 12, 2005
#4
  • May 12, 2005
  • #4
If your pulling 2-3hg more vaccum sounds like you had a vaccum leak from the get go and the computer adjusted for that loss...I would say reset the computer by disconnecting the battery for 30 minutes and then start with adjusting idle and TPS...My 2cents
 

TheRedBlur

Active Member
Jul 7, 2003
15
0
38
seattle
May 12, 2005
#5
  • May 12, 2005
  • #5
LQQKIN4COUPE said:
If your pulling 2-3hg more vaccum sounds like you had a vaccum leak from the get go and the computer adjusted for that loss...I would say reset the computer by disconnecting the battery for 30 minutes and then start with adjusting idle and TPS...My 2cents
Click to expand...

I agree
 

ALMOSTFINISHED

Member
Jan 8, 2004
315
0
17
Westchester County NY
May 13, 2005
#6
  • May 13, 2005
  • #6
I'm gonna third the vacuum leak. Get some carb cleaner and while the engine is idling, spray it around the gasket areas, and vac line areas. If the idle jumps, or smoothes out in a certain spot, it will lead you to the leak. Good luck

Nick
 

RacEoHolic330

I like to dress like a pretty girl
15 Year Member
Mar 4, 2003
4,014
1,698
203
Allentown, PA
May 13, 2005
#7
  • May 13, 2005
  • #7
I reset the ECU today and I also replaced the upper/lower intake gasket. Its seems a little better at cold start-up but when i burp the throttle after the car idles for around 15 seconds it still goes waaaaay rich and make the car bog down and buck. It won't do it if the car idles for a very short time. Maybe I have to let the ECU relearn everything. This issue is beginning to be very angering
 
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