My Fuel injectors are NOT opening ??? Why?

jones

Founding Member
Jan 6, 2001
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0
Miami Florida
I been having fuel problems on my 93 GT for a while now. I changed the fuel pump, fuel fileter, EEC relay, fuel pump relay and i checked all fuses. When i turn the ignition key the fuel pump starts running but it wont stop after 2-4 seconds like it should, and the car wont start either.

THe car has spark but no gas is going past the fuel injectors. I Put gas directly into the air filter and the car started for a couple of seconds. I pushed in the little valve on the fuel rails and it has a real good pressure on the gas, but there is no gas going past the injectos and inside the engine so it wont start.

My question is:

How can i make the injectors open? Is there another relay that i can change?

THe only thing i can think of right now is the computer relay that i bought new was bad and i need to buy another one. :shrug:


Please, someone help me out here. am going crazy.......

Thanks to all of you.
 
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i would jet your sensors and all connections involved with the sensors and relay;s that are associated with the fuel system. my friends bimmer had a problem where at high rpm's no fuel would get to the injectors do to a poor connection on the main injector harness. Once a new one was soldered in it worked fine.
 
DirtyD916 said:
i would jet your sensors and all connections involved with the sensors and relay;s that are associated with the fuel system. my friends bimmer had a problem where at high rpm's no fuel would get to the injectors do to a poor connection on the main injector harness. Once a new one was soldered in it worked fine.


I had the car running very very low on gas one day and it shut off. The fuel pump sayed running after the car shut off, oviously because it had no gas to pump. After that i changed the fuel pump and all and it continues to do the same thing with a full tank of gas.

As soon as i turn the ignition to start it, it will crank and i can hear the fuel pump. The fuel pump wont shut off like it should and the car wont start :bang: . I think it has to do with a relay.

Thanks for the help :nice: , i will eventually have to plug it into a diagnostic computer.
 
There is a tool called a "noid" light that when plugged into any one of the injector connectors, should flash as you crank the vehicle, also check for power at the injector conectors with a test light w/ the clip on the ground side of the battery... A good guess would be ignition module, as since you have spark tells me that the distributor pick-up coil is ok, and the module is what relays TDC to the ecm to begin the injector firing sequence... If you have a known good spare module, give it a try...
 
swiller of beer said:
There is a tool called a "noid" light that when plugged into any one of the injector connectors, should flash as you crank the vehicle, also check for power at the injector conectors with a test light w/ the clip on the ground side of the battery... A good guess would be ignition module, as since you have spark tells me that the distributor pick-up coil is ok, and the module is what relays TDC to the ecm to begin the injector firing sequence... If you have a known good spare module, give it a try...


Hey, Can you please tell me where is the ignition module located? also, what is the difference between TFI ignition module and ignition module?

Thanks alot man, :nice:
 
jones said:
Hey, Can you please tell me where is the ignition module located? also, what is the difference between TFI ignition module and ignition module?

Thanks alot man, :nice:

Ignition module & TFI are the same. On 5.0s built before 94, the are mounted on the distributor.

If you crank the engine for and extended time OR press the throttle to the floor while cranking, it shuts off the fuel to the injectors. The computer thinks the engine is flooded and turns off the injectors in an attempt to clear the engine

Here's a checklist to help troubleshoot your problem. If you follow it, you can find & fix 99% of the no start problems.

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.

4.) Spark & fuel 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.
 
jrichker said:
Ignition module & TFI are the same. On 5.0s built before 94, the are mounted on the distributor.

If you crank the engine for and extended time OR press the throttle to the floor while cranking, it shuts off the fuel to the injectors. The computer thinks the engine is flooded and turns off the injectors in an attempt to clear the engine

Here's a checklist to help troubleshoot your problem. If you follow it, you can find & fix 99% of the no start problems.


I REALY APPRECIATE ALL THE HELP MAN. THANKS ALOT. :nice: