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

A few Questions

  • Thread starter Thread starter Jbabycsx
  • Start date Start date Sep 14, 2010
J

Jbabycsx

New Member
Sep 14, 2010
3
0
0
Sep 14, 2010
#1
  • Sep 14, 2010
  • #1
This is my first post so I will explain my problem and hope that someone can help!

I have a 90 GT 5-speed car that is completely stock(not even a cold air intake). The car has not been molested or hacked to pieces. I just bought it two days ago, though I did own it a few years back as well.

My problem is I notice under moderate to hard acceleration that I lose oil pressure. Under normal cruising the gauge reads around the "A" in NORMAL. When the pressure drops it falls to 0psi. Any ideas? My only thoughts were that the oil pump is going out or maybe a cam bearing?
 
8

87AODGT

Founding Member
Jan 6, 2001
373
1
19
Toms River, NJ
Sep 14, 2010
#2
  • Sep 14, 2010
  • #2
i would put a mechanical gauge on it to see what's really happening, can't put too much faith in the stock sender
 
J

Jbabycsx

New Member
Sep 14, 2010
3
0
0
Sep 14, 2010
#3
  • Sep 14, 2010
  • #3
Thats good advice. I have an extra gauge in my shop. My car had a miss during acceleration when I bought it so I cleaned the MAF, throttle body and IAC. After doing this the car wont idle down. It stays at high RPM when you rev the engine. I bought a new IAC today and put it on, still will not idle down. Any ideas?
 

ttopstang

Active Member
Sep 6, 2007
306
1
28
Birmingham, AL
Sep 14, 2010
#4
  • Sep 14, 2010
  • #4
Check the linkage, could be hung up.
 
L

Lawbreaker5.0

Member
Feb 20, 2009
543
2
18
Texas
Sep 14, 2010
#5
  • Sep 14, 2010
  • #5
Do a base idle reset and then check tps voltage.
 
J

Jbabycsx

New Member
Sep 14, 2010
3
0
0
Sep 14, 2010
#6
  • Sep 14, 2010
  • #6
Ok thanks guys I will try that stuff in the morning. I ran a diagnostic on the EEC and found a few codes so maybe that will help. It is showing the following codes.
51-Engine coolant temp sensor voltage
23-TPS voltage
54-Air charge temp sonsor voltage
85-Canister purge solonoid
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
363
124
Cartersville,Ga
Sep 15, 2010
#7
  • Sep 15, 2010
  • #7
You have 3 codes that share the same circuit. 51 23 and 54. All 3 share the same ground source.

I would clean the larger 10 PIN connectors behind the intake first. Then re-run the codes. Those codes indicate an open in the wiring or a bad connection.
 

mob

the guy who hits on his mom
20+ Year Stangneter
Oct 3, 2003
2,566
136
104
Dallas, TX
Sep 15, 2010
#8
  • Sep 15, 2010
  • #8
Like others have said, before you assume anything or do anything, put a real gauge on there to find out what it is truley at. The stock oil pressure gauge is HORRIBLE, I was having the same problem until I put an electric autometer gauge in and some how the gauge fixed my problem! But really put a real gauge on it, and if the problem persists, you may be looking at an oil pump or bearing issue.

It would suck if you put the gauge on and you are still having the problems, but it will not be a waste of money, being able to accurately read what your car is doing is priceless.
 
K

kingmeirl

Member
Feb 3, 2008
65
0
7
Nov 21, 2010
#9
  • Nov 21, 2010
  • #9
i have the same problem recently with the oil pressure. stock gauge. 93 gt with a few minor mods. I noticed that between 3000 and 3250 rpms it drops to zero psi. It really worries me. Please let us know what you find out, and ill do the same. have you tried a new gauge? I was thinking today it would have to be low on oil to do this, but I have not had a chance to check it out..
 
You must log in or register to reply here.

Similar threads

7
Engine Random hanging idle
  • 706 Saleen
  • Feb 11, 2026
  • Fox 5.0 Mustang Tech
Replies
9
Views
453
Fox 5.0 Mustang Tech Feb 19, 2026
86HO5.0
8
P
Weird Voltage & Oil Pressure Gauges
  • PNN
  • May 22, 2026
  • SN95 V6 Mustang Tech
Replies
0
Views
34
SN95 V6 Mustang Tech May 22, 2026
PNN
P
I
98 Mustang GT dying
  • ItsMason
  • May 14, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
3
Views
77
1996 - 2004 SN95 Mustang -General/Talk- Thursday at 9:50 AM
lenzgt
L
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
Fuel Pressure Regulator or something else?
  • SuperStang83
  • Nov 17, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
14
Views
589
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 25, 2024
BrightVa
B
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?