Cranks OK, but No Start
Checklist for Fuel Injected Mustangs
Courtesy of Stangnet's Jrichker
1.) Remove push on connector from starter solenoid and turn ignition switch on.
in neutral or Park. Remove coil wire from distributor & and hold 3/8” away
from 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:
B.) TFI module
C.) PIP sensor in distributor
D.) ECC relay next to computer - look for 12 volts at the fuel injector red
E.) Fuse links in wiring harness - look for 12 volts at the fuel injector red
F.) Ignition switch - look for 12 volts at the fuel injector red wires
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:
A.) Moisture inside distributor – remove cap, dry off & spray with WD40
B.) Distributor cap
D.) Spark Plug wires
E.) Coil weak or intermittent - you should see 3/8" fat blue spark with a
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.
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
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 ECC test connector and jump the connector in the lower RH
corner to ground. See http://www.mustangworks.com/article...c-iv_codes.html
for a description of the test connector. 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 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
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.) Blown fuse link in wiring harness. Look for 12 volts at the Orange/Lt Blue
wire on the fuel pump relay
F.) Fuel pressure regulator failed. Remove vacuum line from regulator and
inspect for fuel escaping while pump is running.
Fuel pressure OK, the injectors are not firing.
A.) A Noid light available from Autozone, is one way to test the injector
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.
a.) Pull an injector wire connector off and look for 12 volts on the red wire
when the ignition switch is on.
b.) No power, then look for problems with the 10 pin connecter (salt &
pepper shakers at the rear of the upper manifold).
c.) 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
4.) Spark & fuel pressure OK.
A.) Failed IAB (no airflow to start engine).
Press the throttle ¼ way down and try to start
B.) Failed computer (not very likely)
C.) Engine ignition or cam timing off only likely if the engine has been worked
D.) Firing order off: HO & 351 use a different firing order from the non HO