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

Fuel or Electrical issue?

  • Thread starter Thread starter ironheart1
  • Start date Start date Jun 15, 2004

ironheart1

New Member
Mar 13, 2004
131
0
0
Connecticut
Jun 15, 2004
#1
  • Jun 15, 2004
  • #1
Ok guys, I have posted a couple times about my current problem and have recieved a number of useful replies. However, I think I have got the problem nailed down more specifically now.

The car is SLOW right now. REALLY, REALLY SLOW. As in, I got by a stock 4-door automatic Mitsu Mirage. We just did a tuneup (cap rotor wires plugs) and an oil change (castrol syntec and a Mobil 1 filter). After these things were done, my E-Brake light stopped coming all the time when it was engaged with the key on, and I had an insane amount of difficulty starting the car the past couple days. Also, I noticed that my fuel pump doesn't prime every time I turn the key on. It just clicks half the time and nothing else happens, and if I don't keep turning the key from on to off to on again until it primes, it will never start.

I want to get this fixed today. What do I need to buy? I just bought a fuel filter. Is there a relay or somesuch that I should pick up as well?
 

TC93

Well-Known Member
Sep 11, 2000
2,075
1
57
Ellerslie GA 31807
Jun 15, 2004
#2
  • Jun 15, 2004
  • #2
After you change the fliter,check for power at the plug for the fuel pump when you first turn the key on. If it get power everytime, then it may be a fuel pump going bad.
 

ironheart1

New Member
Mar 13, 2004
131
0
0
Connecticut
Jun 15, 2004
#3
  • Jun 15, 2004
  • #3
That sounds like a good idea. I want to go to a 255lph Walbro but money's a bit tight for that at the moment. How would I go about doing that exactly?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Jun 15, 2004
#4
  • Jun 15, 2004
  • #4
The relay is under the driver's seat, a little hard to get to without removing the seat.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-90 wiring

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

The Orange/LT Blue wire is the power feed for the fuel pump relay. The Pink/Black wire feeds power from the relay to the pump.
 

ironheart1

New Member
Mar 13, 2004
131
0
0
Connecticut
Jun 15, 2004
#5
  • Jun 15, 2004
  • #5
Nice, thanks jrichker. Just a couple more things I'd like to touch upon. Is it a safe assumption that the root of my problems is in fact the fuel pump or is fuel-pump related? Or should I keep checking things?

Secondly, I'm an electrical retard and have no idea what I'm going. How would I check safely to see if a wire is getting power?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Jun 15, 2004
#6
  • Jun 15, 2004
  • #6
ironheart1 said:
Nice, thanks jrichker. Just a couple more things I'd like to touch upon. Is it a safe assumption that the root of my problems is in fact the fuel pump or is fuel-pump related? Or should I keep checking things?

Secondly, I'm an electrical retard and have no idea what I'm going. How would I check safely to see if a wire is getting power?
Click to expand...

A fuel pressure gauge is a must have item for testing fuel pump output. Autozone has them for sale, and may have one to rent or loan. You can use a tire gauge in a pinch, but watch out for the squirting fuel.

A test light, or better still a voltmeter, is what's needed to tell if there is power on a wire. If electrical stuff isn't your thing, find a bud who is good at it. That will save you lots of time and trouble unless you want to get a crash course in automotive electrical theory.
 

ironheart1

New Member
Mar 13, 2004
131
0
0
Connecticut
Jun 16, 2004
#7
  • Jun 16, 2004
  • #7
I wasn't able to get into the mechanicals of the car last night but the odd thing is, it primes every time now. I'm really curious to know what in the blue blazes is wrong with this thing :damnit:

I've gotten a ton of suggestions, I can only hope that I'll have some success tonight. Does anyone have a picture of where the O2 sensors plug in on an 88? Also, has anyone had problems with Bosch 8mm wires breaking or snapping in some way?
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Jun 16, 2004
#8
  • Jun 16, 2004
  • #8
O2 sensors are on the H pipe in the area of the bellhousing. If you haven't dumped the codes, do so before spending $$$ on new O2 sensors.

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html
 

ironheart1

New Member
Mar 13, 2004
131
0
0
Connecticut
Jun 16, 2004
#9
  • Jun 16, 2004
  • #9
I'll have to wait until I get to my friend's place tonight to use the test light. My Check Engine light doesn't function I don't believe, I've had the car for over a year, had TONS of problems and never a check engine light. Plus, it doesn't come on when I turn the key to the on position.

Jrichker - You *are* the man.
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Jun 16, 2004
#10
  • Jun 16, 2004
  • #10
ironheart1 said:
I'll have to wait until I get to my friend's place tonight to use the test light. My Check Engine light doesn't function I don't believe, I've had the car for over a year, had TONS of problems and never a check engine light. Plus, it doesn't come on when I turn the key to the on position.

Jrichker - You *are* the man.
Click to expand...

The 88 had no check engine light, the Califonia models may be the exception. You have to use a test light or voltmeter to get the codes. The links all explain how to do it with a test light or voltmeter.
 

ironheart1

New Member
Mar 13, 2004
131
0
0
Connecticut
Jun 16, 2004
#11
  • Jun 16, 2004
  • #11
Really... That's odd, because I know for sure that the 85mph gauge cluster I have has provisions for a check engine light, apparently it lacks the hookups for it but my backlighting is so bright at night I can see the light behind the "Check Engine" display.

I of course believe you, but I do think that that is strange.
 
You must log in or register to reply here.

Similar threads

Engine Fuel not pumping
  • Creomod
  • Apr 13, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
51
Views
1K
Fox 5.0 Mustang Tech Jul 22, 2026
Noobz347
B
Electrical Why does my fox body keep frying eecs
  • brandyn200
  • Jun 20, 2026
  • Fox 5.0 Mustang Tech
Replies
8
Views
281
Fox 5.0 Mustang Tech Jun 25, 2026
AeroCoupe
L
1997 V6 Starting issue
  • leanzik04
  • Mar 20, 2026
  • SN95 V6 Mustang Tech
Replies
3
Views
252
SN95 V6 Mustang Tech Mar 20, 2026
Noobz347
C
98 gt fuel pressure issues
  • chasecollier1984
  • Jun 2, 2026
  • SN95 4.6L Mustang Tech
Replies
0
Views
94
SN95 4.6L Mustang Tech Jun 2, 2026
chasecollier1984
C
A
1987 5.0 speed density Foxbody crank no start
  • Alan2204
  • May 23, 2026
  • Fox 5.0 Mustang Tech
Replies
10
Views
318
Fox 5.0 Mustang Tech May 30, 2026
Mcmahst
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?