92 firing problems

Hey its me again. Well we finally got the car to fire, i had to rewire the coil because the previous owner did such a shotty job on it, so i did that, then we decided to use ether to start it, following jrichker's advice. It started up sure enough, but there is fuel pressure up to the schrader valve, where i have my fuel pressure gauge hooked up, so we were thinking, could the EEC possibly be preventing the injectors from...well...injecting?????
 
Put a noid light on a given injector. That will tell you if you have the key-on 12-volts and controlled-ground (from the computer), which are needed excite the injectors.
That does not mean they are actually firing, but for all of them to fail at once is not real likely. Now them missing one of the two ingredients is more likely.

Good luck.
 
i might have found the problem. there is a relay in my enigne compartment that had fallen down and rested on the headers, and melted big time. Its a 5-prong relay with only 4 wires connecting to it (white, pink stripe/white, red, and black/yellow stripe), so i found a replacement down at advance, and still won't start, so could it have damaged the relay connected to the EEC? I took that one off and am thinking about replacing it. Should i spend my money or do ya'll think it's something else? -Jordan
 
Where is the relay located? Starting in late '92, they started putting the fuel pump relay in the engine compartment next to the WOT relay. It is on the pass side behind the air inlet tube (next to the strut tower).


I do have to say that given the colors you provided, it sounds like you are talking about the WOT relay (not the FP relay).
 
ZephyrMotorspor said:
whats WOT? but the relay i'm talking about has 4 prongs and hangs right up against the computer, which is behind the kick panel on the pass. side, in my car b/c thats where the guy put it, b/c the engine used to be n/a
Jordan, you are confusing me. Above you mention a relay hitting the headers. Now you mention the EEC relay (which is right next to the computer in the pass kick panel).

FWIW, whether a car is N/A or forced induction, the computer normally does not move.

And WOT = Wide Open Throttle.

Good luck.
 
i just replaced the relay that got melted last night, i replaced the one hanging up against the EEC tonight. which one is the latter? i don't think there's anything wrong with my fuel pump, i can hear it, and my inertia switch isn't tripped...so what the balls?
 
The fact that you have fuel pressure tells me that you have power to the computer. Do you have spark?

For sake of not over looking anything, I'll repost the Cranks OK, but no start checklist for fuel injected Mustangs checklist. Tell me where you are on the checklist and we can work from there.

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.) MSD or Crane ignition box if so equipped
B.) Coil
C.) TFI module
D.) PIP sensor in distributor
E.) ECC relay next to computer - look for 12 volts at the fuel injector red wires
F.) 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.
G.) Ignition switch - look for 12 volts at the ignition coil red/lt green wire. There is a separate blue fuse link for the coil which can open up and rob the coil of power.
H.) Computer

See the following links for wiring diagrams...

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model cars


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. 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 have.

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. The fuse links live in the wiring harness near the starter solenoid.
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 wiring.
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 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 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.
 
i think here:

Fuel pressure OK, the injectors are not firing.

A.) A Noid light available from Autozone, is one way to test the injector wiring.
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. what exactly is a noid light? is it like a test light or what?
 
ZephyrMotorspor said:
i think here:

Fuel pressure OK, the injectors are not firing.

A.) A Noid light available from Autozone, is one way to test the injector wiring.
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. what exactly is a noid light? is it like a test light or what?
Hmm, For what little it is worth, you can see my two cents in my first post here. A wiring issue is a LOT more likely than a hard-part injector failure. Jrichker can provide you with a lot more info. Did you ever use a noid light on any of the injector harness connectors?

Good luck.
 
I'm broke right now but as soon as i can i will. I'm 17 and making minimum wage at a job where the mangers won't give me anymore time. And this car's starting to nickel and dime me pretty damn bad lol but as of now I have over 2100 in it, including the car which i talked down to 1700 from 2200. Looking back i might have gone with a like and old malibu with like a 350 cuz my dad used to be a race car driver, and pretty much knows the sb chevy inside and out, but i can't really change horses in the middle of the stream. Besides, i've always like the fox bodies and i wanted this to be a project car. I'm planning on saving up some cash and getting a Edelbrock performer, holley 4160, and a fuel pres. regulator, but along with that i have to save some cash for my girlfriend's birthday cuz i'm getting her something from tiffany's lol so it'll take me a while before i can sack this EFI crap.