Please help me identify a relay ?

jones

Founding Member
Jan 6, 2001
91
0
0
Miami Florida
Ok,

I have a 93 Mustang GT. I have bought every god damn thing i can buy and am going krazy. I posted this before but maybe someone that had the same problems can help me now.

This is how it all started:

I had the car running very low on gas until it shut off do to no gas. I whent and put about 10+ gallons and it wouldnt start. I would turn the ignition key on and the fuel pump would prime but it wont shut after a few seconds like it should, it would just keep going and going as long as the ignition key was on, just like if it had no gas on the tank. So, i put some gas on the intake and it started for a few seconds. Its ovious the injectors are not opening up.

I got spark, I got fuel pressure in the rails but no gas is going past the injectors. The injectors are getting power (tested with testlight)


Changed TFI module, cap/rotor, wires, fuel pump, fuel filter, fuel pump relay, ecu relay, inertia switch is good. There is another fuse next to my fuel relay that i dont know what it is ??? :shrug: it looks just like the fuel pump relay and its right next to it.

How can i make my injectors open again so my car can get gas and start ?

Can anyone help me out :bang:

Thanks in advanced!
 
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I would verify that you actually have fuel reaching the injectors instead of just pressurized air with the fuel stuck behind it. Open the shrader to make sure that a good flow of fuel comes out. The fuel pump may have lost prime. I had that happen with a low pressure (carb) pump one time. Had FP bun no actual fuel reached the bowls for several minutes.
 
Cranks OK, but No Start Checklist for Fuel Injected Mustangs

1.) Remove push on connector from starter solenoid and turn ignition switch on. Place car 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:
A.) Coil
B.) TFI module
C.) PIP sensor in distributor
D.) ECC relay next to computer
E.) Fuse links in wiring harness
F.) Ignition switch
G.) Computer

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
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 ECC test connector and jump the connector in the lower RH corner to ground. See http://www.mustangworks.com/articles/electronics/eec-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.

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.
C.) Clogged fuel filter
D.) Failed fuel pump
E.) Blown fuse link in wiring harness.
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 Noid light available from Autozone, is one way to test the injector wiring. 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 connectors.


4.) Spark & fuel pressure OK.
A.) Failed IAB (no airflow to start engine). Press the throttle ¼ way down and try to start the car.
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 form the non HO engines.