High Idle...Again

sandman0023

New Member

Aug 21, 2004

116

0

0

Chicago

Nov 15, 2004

#1

• Nov 15, 2004

• #1

I've had a high idle problem for a while. I'll be sitting at a stop sign or light and the engine will rev up and stick. I'll be pushing around 2500-3000 rpms. While I'm shifting, same thing. I replaced the throttle body and EGR plate and it still did it.

Yesterday I went to Kragen and ran it on the code machine. It came up with 2 codes: 33 and 4. I looked up 33 and it said it was the EGR Valve. I replaced that today and it was fine for a few test drives. Then it came back. Not as bad as before but it is still there. I'm going to replace the vacuum line to the EGR Valve tommorow and see if that does the trick. Anyone have another idea? Also, what is code 4?

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

2,120

2

59

windsor, Canada

Nov 15, 2004

#2

• Nov 15, 2004

• #2

do the idle set from the corral tech area, then after (or before) spend some serious time looking for hidden cracked or broken vac lines..I hooked over the engine bay probably 20x's before I found the bad one in the passenger fender...TADA surge and hanigng idle gone like magic. Just a tip, hope all goes well.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

Nov 15, 2004

#3

• Nov 15, 2004

• #3

i'm with Dman - check for vac leaks. the lines under the upper (in the front) are notorious for leaking/cracking.

often the EGR and sensor interface is off. the new valve should have corrected this, but i might check the EGR seat to sensor interface to be sure.

not sure there is such a thing as a code 4. the codes are double digit for us, triple for SN pushrod motors, i think.

good luck.

 

DoubleAgentMan

Founding Member

May 2, 2002

151

0

16

South Texas

Nov 15, 2004

#4

• Nov 15, 2004

• #4

You have some great advice....Most of the time these idle problems seem to almost always end up being vac leak related...but here is something else if you haven't tried it already, and it's free....can't beat that right?

Ten pins

And if I'm not mistaken (usually wrong though.. ),I think the "4" you got might have just been the ingine ID bleeps you get when running the codes..I want to remember that 4 is for a V8 and 2 is for a 4cyl....I could be way off on that though...

Hope some of this stuff helps you out man...

 

I

Idwitheld-1`

New Member

Nov 30, 2003

335

0

0

Portland Oregon

Nov 15, 2004

#5

• Nov 15, 2004

• #5

That's quite a jump. Would be a big vacuum line... HISSIN is right. Look closely at the vacuum tree lines under the upper plenum, very prone to heat rot. Also, check the PCV line. I left this out once and started the car and it idled at 2500 rpm's like yours.

 

dastang2

Active Member

Dec 11, 2003

2,020

0

46

tx

Nov 15, 2004

#6

• Nov 15, 2004

• #6

while it is running spray starting fluid over all of the vacuum lines and ports, if the motor revs, look in that area for leaks

 

B

BlueThunder1988

New Member

May 19, 2003

102

0

0

Nov 16, 2004

#7

• Nov 16, 2004

• #7

I fought that same problem--the mysterious jump in idle to 2,800 or so at at stop in traffic--along with a high/hanging idle that would be fixed (at least somewhat) by cycling the ignition off/back on. I replaced the TPS and tada! Problem fixed! Finally fun to drive the 5.0 again! A few others have reported this same issue fixed with a TPS swap so do check into it.

 

sandman0023

New Member

Aug 21, 2004

116

0

0

Chicago

Nov 16, 2004

#8

• Nov 16, 2004

• #8

I just replaced the throttle body and control module on the front of the TB (can't think what it is called) I switched out the EGR valve and sensor yesterday. It was fine for a while then started up again. The TPS is on the bottom of the TB, correct? If so, the new TB has one. I'm going to do what Corral said and then start looking for vacuum today.
Thanks

 

sandman0023

New Member

Aug 21, 2004

116

0

0

Chicago

Nov 16, 2004

#9

• Nov 16, 2004

• #9

Well, I did just what the tech article at Corral said and drove it for a little while and it seems fine. I'll drive it to and from work tomorrow and let you guys know.

 

L

lit_mike_2001

New Member

Jan 25, 2003

163

1

0

Ada, OK

Nov 16, 2004

#10

• Nov 16, 2004

• #10

efi sucks

 

89MustangGX

I have nothing productive to add!

Jul 3, 2001

10,262

1

0

Mill Creek, WA

Nov 16, 2004

#11

• Nov 16, 2004

• #11

If you still run into trouble -- I agree with all of the above. I'll second the 10-pin connectors being cleaned out, as well as the IAB being helpful.

 

sandman0023

New Member

Aug 21, 2004

116

0

0

Chicago

Nov 17, 2004

#12

• Nov 17, 2004

• #12

Well, that didn't work. Starting to search for vacuum lines. Is there more than one way to do this?