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  • Fox 5.0 Mustang Tech

won't start any tips

  • Thread starter Thread starter ebone84
  • Start date Start date Jul 5, 2009
E

ebone84

20+ Year Stangneter
Jun 8, 2004
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39
Jul 5, 2009
#1
  • Jul 5, 2009
  • #1
i tucked my wires that came out good. car turns over but won't start , what are some of the basic things to check for and how..... Thanks
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
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Dublin GA
Jul 5, 2009
#2
  • Jul 5, 2009
  • #2
No info about your car's model year, EFI or carb, no mods listed. Makes it hard to troubleshoot when we don't know what you have.

Therefore, no clue as to which wiring diagram you need. The wiring changed several times between 79 & 95.

That's why it is a good idea to use the sig under the user control panel (User CP) option. It allows you to post your car year & mods, which help greatly when troubleshooting things. No, it is not there for us to snoop and see any "Secrets" you have hidden away under the hood. Be a good stangnetter and update you sig for future reference & don't keep us guessing.
 
E

ebone84

20+ Year Stangneter
Jun 8, 2004
125
40
39
Jul 6, 2009
#3
  • Jul 6, 2009
  • #3
91 gt supercharged vortech 42lbs, typhoon intake, mds 6al ..... turns over
 

jrichker

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#4
  • Jul 6, 2009
  • #4
Cranks OK, but No Start Checklist for Fuel Injected Mustangs

A word about this checklist before you start: it is arranged in a specific order to put the most likely failure items first. That will save you time, energy and money. Start at the top of the list and work your way down. Jumping around will possibly cause you to miss just what you need to see to find and fix the problem. Don’t skip any steps because the next step depends on the last step working correctly.


Revised 19-Jun-2009 to clarify ignition switch & coil power states.
All text applies to all models unless stated otherwise.

Note: 94-95 specific changes are in red

1.) Remove push on connector (small red/blue wire) from starter solenoid and turn ignition switch on. Place car in neutral or Park and set the parking brake. Remove the coil wire from distributor & and hold it 3/8” away from the engine block. Jumper the screw to the big bolt on the starter solenoid that has the battery wire connected to it. You should get a nice fat blue spark.
Most of the items are electrical in nature, so a test light, or even better, a voltmeter, is helpful to be sure they have power to them.

No spark, possible failed items in order of their probability:
A.) MSD or Crane ignition box if so equipped
B.) PIP sensor in distributor. The PIP sensor supplies the timing pulse to trigger the TFI and injectors. A failing PIP sensor will sometimes let the engine start if the SPOUT is removed. See paragraph 5A - a noid light will tell if the pip is working by flashing when the engine is cranking.
C.) TFI module: use a test light to check the TFI module. Place one lead of the test light on the red/green wire on the ignition coil connector and the other lead on the dark green/yellow wire on the ignition coil connector. If the TFI is working properly, the test light will flash when the engine is cranked using the ignition switch.
D.) Coil
E.) No ECC or computer power - ECC or computer relay failure
86-93 models only: ECC relay next to computer - look for 12 volts at the fuel injector red wires
94-95 models only: EEC or PCM power relay in the constant control relay module. Look for 12 volts at the fuel injector red wires.
F.) No ECC or computer power - fuse or fuse link failure
86-93 models only: Fuse links in wiring harness - look for 12 volts at the fuel injector red wires. All the fuse links live in a bundle up near the starter solenoid.
94-95 models only: 20 amp EEC fuse in the engine compartment fuse box. Look for 12 volts at the fuel injector red wires.
G.) Ignition switch - look for 12 volts at the ignition coil red/lt green wire. No 12 volts, blown fuse link or faulty ignition switch. Remove the plastic from around the ignition switch and look for 12 volts on the red/green wire with the switch in the Run position. No 12 volts and the ignition switch is faulty. If 12 volts is present in the Run position at the ignition switch but not at the coil, then the fuse or fuse link is blown.
Note: fuses or fuse links blow for a reason. Don’t replace either a fuse or fuse link with one with a larger rating than stock. Doing so invites an electrical fire.
Ignition fuse links may be replaced with an inline fuse holder and 5 amp fuse for troubleshooting purposes.
94-95 models only: Check inside fuse panel for fuse #18 blown – 20 amp fuse
H.) Missing or loose computer power ground. The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery. It is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire. You'll find it up next to the starter solenoid where the wire goes into the wiring harness
I.) Computer.
J.) Bad or missing secondary power ground. It is located between the back of the intake manifold and the driver's side firewall. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges.
K.) Engine fires briefly, but dies immediately when the key is released to the Run position. Crank the engine & when it fires off, pull the small push on connector (red wire) off the starter relay (Looks like it is stuck on a screw). Hold the switch in the crank position: if it continues to run there is a problem with either the ignition switch or TFI module. Check for 12 volts at the red/green wire on the coil with the switch in the Run position. Good 12 volts, then replace the TFI. No 12 volts, replace the ignition switch.

Wiring Diagrams:…

Sorry, the AutoZone wiring diagram links no longer work. You can navigate to the diagrams yourself via http://www.autozone.com/autozone/repairinfo/repairInfoLanding.jsp and select the car year, make, model and engine. That will enable you to bring up the wiring diagram for your particular car.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring Mustang FAQ - Engine Information Everyone should bookmark this site.


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

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 94-95 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/94-95_5.0_EEC_Wiring_Diagram.gif

2.) Spark at coil wire, pull #1 plug wire off at the spark plug and check to see spark. No spark, possible failed items in order of their probability: [/b]
A.) Moisture inside distributor – remove cap, dry off & spray with WD40
B.) Distributor cap
C.) Rotor
D.) Spark Plug wires
E.) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil

3.) Spark at spark plug, but no start.
Next, get a can of starting fluid (ether) from your local auto parts store: costs a $1.30 or so. Then pull the air duct off at the throttle body elbow, open the throttle, and spray the ether in it. Reconnect the air duct and try to start the car. Do not try to start the car without reconnecting the air duct.

Two reasons:
1.) If it backfires, the chance for a serious fire is increased.
2.) On Mass Air cars, the computer needs to measure the MAF flow once the engine starts.
If it starts then, you have a fuel management issue. Continue the checklist with emphasis of fuel related items that follow. If it doesn’t, then it is a computer or timing issue: see Step 4.

Clue – listen for the fuel pump to prime when you first turn the ignition switch on. It should run for 5-20 seconds and shut off. To trick the fuel pump into running, find the EEC test connector and jump the connector in the Upper RH corner to ground. The EEC connector is near the wiper motor and LH hood hinge.


If the relay & inertia switch are OK, you will have power to the pump. Check fuel pressure – remove the cap from the Schrader valve behind the alternator and depress the core. Fuel should squirt out, catch it in a rag. Beware of fire hazard when you do this. In a pinch, you can use a tire pressure gauge to measure the fuel pressure. It may not be completely accurate, but you will have some clue as to how much pressure you have. If you have any doubts about having sufficient fuel flow/pressure, rent a fuel pressure test gauge from the auto parts store. That will tell you for sure if you have adequate fuel pressure.


4.) No fuel pressure, possible failed items in order of their probability:
A.) Tripped inertia switch – Coupe & hatch cars hide it under the plastic trim covering the driver's side taillight. Use the voltmeter or test light to make sure you have power to both sides of the switch
B.) Fuel pump power relay – located under the driver’s seat in most stangs built before 92. On 92 and later model cars it is located below the Mass Air Flow meter. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
C.) Clogged fuel filter
D.) Failed fuel pump
E.) 86-90 models only: Blown fuse link in wiring harness. Look for 12 volts at the Orange/Lt Blue wire on the fuel pump relay.
91-93 models only Blown fuse link in wiring harness. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
The fuse links for all model years 86-93 live in the wiring harness near the starter solenoid.
94-95 models only: 20 amp fuel pump fuse in the engine compartment fuse box. Look for 12 volts at the Dark green/yellow wire on the constant control relay module.
F.) Engine seem to load up on fuel and may have black smoke at the tailpipe. Fuel pressure regulator failed. Remove the vacuum line from the regulator and inspect for fuel escaping while the pump is running. If fuel is coming out the vacuum port, the regulator has failed. Check the regulator vacuum line for fuel too. Disconnect it from the engine and blow air though it. If you find gas, the regulator has failed.

5.) Fuel pressure OK, the injectors are not firing.
A.) The PIP sensor in the distributor tells the computer when to fire the injectors. A failing PIP sensor will sometimes let the engine start if the SPOUT is removed.
A noid light available from any auto parts store, is one way to test the injector circuit to see if the injectors are firing. The noid light plugs into the fuel injector harness in place of any easily accessible injector. Plug it in and try to start the engine: it will flash if the injector is firing.
B.) I like to use an old injector with compressed air applied to the injector where the fuel rail would normally connect. I hook the whole thing up, apply compressed air to the injector and stick it in a paper cup of soapy water. When the engine cranks with the ignition switch on, if the injector fires, it makes bubbles. Cheap if you have the stuff laying around, and works good too.
D.) Pull an injector wire connector off and look for 12 volts on the red wire when the ignition switch is on.
E.) No power, then look for problems with the 10 pin connecter (salt & pepper shakers at the rear of the upper manifold).
F.) No power and the 10 pin connections are good: look for broken wiring between the orange/black wire on the ECC relay and the red wire for the 10 pin connectors.
G.) TPS voltage exceeds 3.7 volts with the throttle closed. This will shut off the injectors, since the computer uses this strategy to clear a flooded engine. Use a DVM, a pair of safety pins, and probe the black/white and green wires to measure the TPS voltage.
On a 94-95 Mustang, probe the black/white and grey/white wires to measure the TPS voltage.
It should be .5-.1.0 volts with the key on, engine not running. Note that if the black/white wire (signal ground) has a bad connection, you will get some strange readings. Make a second measurement using the battery post as the ground to eliminate any ground problems. If the readings are different by more than 5%, you may have a high resistance condition in the black/white signal ground circuit.

6.) Spark & fuel pressure OK.
A.) Failed IAB or improperly set base idle (no airflow to start engine). Press the throttle ¼ way down and try to start the car. See the "Surging Idle Checklist for help with all your idle/stall problems.
B.) Failed computer (not very likely)
C.) Engine ignition or cam timing off: only likely if the engine has been worked on recently).
D.) Firing order off: HO & 351 use a different firing order from the non HO engines.
HO & 351W 1-3-7-2-6-5-4-8
Non HO 1-5-4-2-6-3-7-8
E.) No start when hot - Press the throttle to the floor & try starting it if you get this far. If it starts, replace the ECT.
F. ) Engine that has had the heads off or valves adjusted. Do a compression test to make sure the valves are not adjusted too tight. You should have a minimum of 90 PSI on a cold engine.
 
E

ebone84

20+ Year Stangneter
Jun 8, 2004
125
40
39
Jul 6, 2009
#5
  • Jul 6, 2009
  • #5
my car turns over but the fuel pump only works when i jump the relay and then it still wont start, is there a circuit that turns everything else on.... i'll hate to pull out all of my wires again...thanks for any help...and i will go down the list if i have to.... just trying to get some tips....
 

AnthonyR23

Member
Sep 8, 2006
661
0
16
Ontario
Jul 7, 2009
#6
  • Jul 7, 2009
  • #6
What did you do in between last time it started and now. Did you change anything with the distributor? I'm confused with your situation. Have you had this car running and it just won't start, has it sat all year, did you change something. What's going on. Honestly I'm sure people here can help, just try to be a little more specific about your situation.


"won't start any tips
i tucked my wires that came out good. car turns over but won't start , what are some of the basic things to check for and how..... Thanks ???"

Confused sorry!
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
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234
Dublin GA
Jul 7, 2009
#7
  • Jul 7, 2009
  • #7
ebone84 said:
...and i will go down the list if i have to.... just trying to get some tips....
Click to expand...

It sounds like you really don't want to invest any effort to get the car running...

Good troubleshooting takes time. Everyone seems to be looking for
the magic tip that says replace this $13 part and your problems are
cured. You don't have to think, dig or diagnose, just buy the part and
install it. Unfortunately, it doesn’t work that way 99% of the time.
Thinking is hard work and educated thinking requires much more
effort than simple parts swapping. The complexity and age of these
5.0 Mustangs works against that, as well as the number of hands
that have “modified” the original design. Sometimes that
modification is well done with good workmanship and other times it
is mechanical road kill. It is very easy to become the victim of the
previous owner’s efforts.

I spend a great deal of time trying to communicate the methodology
of structured troubleshooting principles. For those who haven’t been
beaten with this stick before, here they are again:

1.) Understand the system. That involves reading some books to get
an overall picture of how it works. For 5.0 Mustangs, that list starts
with the Chilton shop manual and the Probst book, Ford Fuel
Injection & Electronic Engine Control 1988-1993 by Charles
Probst :ISBN 0-8376-0301-3. It's about $30 from Borders.com, see
Amazon.com: Online Shopping for Electronics, Apparel, Computers, Books, DVDs & more. Select books and then select
search. Use the ISBN number (without dashes or spaces) to do a
search. Use the ISBN number and your local library can get you a
loaner copy for free for 2 weeks or so. Another resource is the
following website by Tmoss (diagram designer) & Stang&2Birds
(website host) for help on 88-95 wiring:
Mustang FAQ - Engine Information. Study
the diagrams and tech articles. There is an amazing amount of good
stuff in one place for FREE.

2.) Isolate the problem. You need to be able to break the system
down into functional blocks or subsystems. Once you know what
subsystem has failed, it is much easier to troubleshoot. Group
problem symptoms according to what system controls them. Don’t
look for a fix for ignition problems by adjusting the fuel pressure.
Have an organized, step by step, approach to work your way through
a subsystem and check its functions. Work all the way through a
subsystem before you quit and go off wildly chasing rabbits. You
have three tools to use in your efforts: measure, meter and
observe
. Use these three tools to narrow down the list of possible
failure points into a small, easily managed list of items.

3.) Install the fix. .Now that you have a short list of suspected
villains, plan your repair efforts so that you do the easy things first.
If an item from the easy list didn’t fix your problem, then look at the
high failure rate items. Spend some time here on Stangnet and you’ll
get an idea of what the most commonly replaced parts are, things
like TFI modules, ignition switches and fuel pumps.

If you make a change and it doesn’t relieve the problem symptoms,
put it back the way it was. I have a stack of parts from where I
swapped a part and it didn’t fix the problem. I put the old part back
on the car and the new part went on the shelf. Someday I will either
use them or trade them for something else.
 
E

ebone84

20+ Year Stangneter
Jun 8, 2004
125
40
39
Jul 7, 2009
#8
  • Jul 7, 2009
  • #8
this is getting deep, just looking for some thoughts or maybe a tip....like what might i check that triggers my car car to start.... to save me alittle time... the checklist is great, but a good tip can also help.....
 
J

jmd2914

Founding Member
Sep 6, 2002
937
0
0
Napa, California
Jul 7, 2009
#9
  • Jul 7, 2009
  • #9
thats what hes trying to tell you. the list he posted is the " tip" youre looking for, you just have to put in the leg work and go through it. the man knows what hes talking about, his suggestions and write-ups have helped me countless times with trouble shooing
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Jul 8, 2009
#10
  • Jul 8, 2009
  • #10
As noted, just run the list. You noted in your first post that you desired info on what to do and how to do it. If unclear about performing a test in the checklist, simply post your questions. Though not directed at you, sometimes people don't post that they didnt understand and they don't do the tests correctly. That's just a waste of time.

Because you moved, cut, soldered wires, all bets are off with anyone being able to guess about where the issue is. The list will help you narrow it down by the system and not by what work was done on the car (at least initially).

Good luck.
 
E

ebone84

20+ Year Stangneter
Jun 8, 2004
125
40
39
Jul 8, 2009
#11
  • Jul 8, 2009
  • #11
all tips are welcome.... anyway went to harbor freight, got some junk so now i can dive into this..... i'll buy the beer... pontiac,mi
 
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