• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

1500 Idle After Mods

  • Thread starter Thread starter 87slvrstang
  • Start date Start date Sep 12, 2009
8

87slvrstang

New Member
Sep 12, 2009
6
0
2
Sep 12, 2009
#1
  • Sep 12, 2009
  • #1
Hey everyone, I am new to the forum and hope to get a little help. I have a 87 notch 5.0. I removed all the smog equipment, capped the lines and plugged the back of the heads, removed the pump and changed the belt. I also changed the exhaust to an o/r h with flowmaster mufflers. I changed all this today and then sprayed the engine down with cleaner and rinsed it off. Now when the car is in park or neutral it idles around 1500 rpm. No stalling or anything crazy in gear moving or stopped, only in park or idle. When I got home from driving it, it was around 800. I started again an hour later and it was back up again. Is it something I missed with the smog removal or possibly I sprayed water in something? Other than idle in park or neutral the car runs great.
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
363
124
Cartersville,Ga
Sep 12, 2009
#2
  • Sep 12, 2009
  • #2
Check your vac lines by the Solenoids behind the passenger side strut tower.
 
8

87slvrstang

New Member
Sep 12, 2009
6
0
2
Sep 12, 2009
#3
  • Sep 12, 2009
  • #3
they looked good earlier, but you might be right, I will go out and check them again.
 
8

87slvrstang

New Member
Sep 12, 2009
6
0
2
Sep 12, 2009
#4
  • Sep 12, 2009
  • #4
All the vacuum lines look good and fully connected.
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
363
124
Cartersville,Ga
Sep 12, 2009
#5
  • Sep 12, 2009
  • #5
Since you done away with the smog system, you can get rid of the two solenoids that are side by side. And all the vac lines that go with them. And if your not using the EGR you can do away with the one above it too.

It would atleast get rid of all the vacuum lines.

Anyways, you could do a code scan, pretty sure something will show that may help here.
 
8

87slvrstang

New Member
Sep 12, 2009
6
0
2
Sep 12, 2009
#6
  • Sep 12, 2009
  • #6
Just so I am sure, the solenoids I can get rid of are the same ones on the bottom behind the passenger strut tower right? I still have the egr. If I get rid of it do I need something to keep it from getting a code or light? Will resetting the cpu help with idle? I was just curious as I did not know if removing the smog system and changing exhaust affected it.
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
363
124
Cartersville,Ga
Sep 12, 2009
#7
  • Sep 12, 2009
  • #7
87slvrstang said:
Just so I am sure, the solenoids I can get rid of are the same ones on the bottom behind the passenger strut tower right?
Click to expand...

Yup, you can remove them, and it wont throw a CEL. Removeing the SMOG wont cause any issues.



You need to run the codes from the ECM.
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Sep 13, 2009
#8
  • Sep 13, 2009
  • #8
liljoe07 said:
Yup, you can remove them, and it wont throw a CEL. Removeing the SMOG wont cause any issues.



You need to run the codes from the ECM.
Click to expand...

The CEL won't set, but the computer will post 81 & 82 when you dump the codes.

Here's the fix for that...

TAB & TAD solenoid valve eliminators – eliminate codes 81 & 82.
You will still get 44 & 94 codes because the computer looks for a change in the amount of oxygen by checking the O2 sensors when the solenoids are actuated. Actuating the solenoids provides more oxygen in the exhaust, changing the O2 sensor output. No change and you get the 44 & 94 codes.

Don’t do this if you have a catalytic converter H pipe. The catalytic converters must have the air from the smog pump or they will eventually clog up and choke.

See US - Electronic Components Distributor | Newark.com for the resistors to replace the TAB & TAD solenoids

OHMITE|43F82RE|Wirewound Resistor | Newark.com
If the link fails do a search using the part number
82 ohm, 3 watt wirewound resistor, 94 cents each.
Newark P/N 64K8974
Ohmite part # 43F82RE.
Or use the following part number if the first part number isn't available:
OHMITE|23J82RE|Wirewound Resistor - Vitreous | Newark.com
Newark P/N 64K8241
Ohmite part #23J82RE

Pay a visit to your local Radio Shack to get some heat shrink and some crimp on tap terminals. They do not stock the resistors. Or you can use the Ford connector pin kit from AutoZone.


18 gauge crimp on taps Catalog #: 64-3053

Put the resistor inside the heat shrink tubing and crimp the connectors on. I would choose the Ford pin connectors since they should plug in the TAB & TAD wiring. That way you haven't modified the wiring so it is easy to re-install the TAB & TAD solenoids if emissions testing comes to your area.


Two flat pin connectors.
One 82 ohm, 3 watt resistor.
One piece 3/8" heat sink tubing 2" long.
Two pieces 3/16" heat shrink tubing 1 1/2" long.
Solder the pins onto the resistor leads using electrical solder.
Slide the 3/8" heat shrink tubing over the resistor.
Slide the two pieces of 3/16" heat shrink tubing over the two wires, leaving the flat part of the pins uncovered.


It helps to have the resistor leads straight and not bent as shown in the first picture when you apply heat to the heat shrink tubing. That way, the tubing shrinks more evenly.
Finally, apply heat to shrink all the tubing uniformly.



Bend the leads to fit the spacing on the female TAB & TAD connector sockets.



Push the connector pins of the completed resistor assembly into the empty female TAD or TAD connector sockets on the wiring harness. The resistor assemblies replace the missing solenoids: one resistor assembly per solenoid socket.

Do not crimp on the pins and wrap the mess with electrical tape and say you got the idea from me. If you do, and I hear of it, I will say unkind things about your intelligence and family heritage. Do Quality Work!

This information is for informational purposes only and is intended for use only on off road vehicles. It should not be used on any vehicle operated on public roads.

Operating a vehicle modified in such a manner on public roads is a violation of the EPA codes regarding modification of emission controlled vehicles.



Idle/surge problems:
See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.
 
8

87slvrstang

New Member
Sep 12, 2009
6
0
2
Sep 13, 2009
#9
  • Sep 13, 2009
  • #9
Thanks for the help. Great info!
 
You must log in or register to reply here.

Similar threads

Engine Surging idle on start-up
  • keel
  • Aug 11, 2025
  • Fox 5.0 Mustang Tech
Replies
16
Views
839
Fox 5.0 Mustang Tech Oct 31, 2025
keel
S
Fox '87 GT can't get to stay running
  • spilly
  • Mar 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
27
Views
653
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 20, 2026
spilly
S
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
SURGING IDLE / NO IDLE CHECKLIST FOR 1996–1998 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
696
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
SURGING IDLE / NO IDLE CHECKLIST FOR 1999–2004 MUSTANG GT (4.6L 2V) - Work In Progress
  • Noobz347
  • Aug 30, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
829
1996 - 2004 SN95 Mustang -General/Talk- Aug 30, 2025
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?