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347 only starts with wide open throttle

  • Thread starter Thread starter Mizark347
  • Start date Start date Jun 28, 2004
M

Mizark347

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Jan 21, 2004
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Jun 28, 2004
#1
  • Jun 28, 2004
  • #1
My car wont start unless i have the pedal to the floor. when it does start its hard to get it to idle. Could this be because im not getting enough fuel? stock pump and regulator.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
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#2
  • Jun 29, 2004
  • #2
pedal to the floor cuts the injectors (to clear flooding). i dont have an answer for you, but thought i would toss that info out. have you pulled a plug to see how they look (soaked with fuel, etc?)
good luck.
 
D

D347643

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Jan 28, 2003
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Jun 29, 2004
#3
  • Jun 29, 2004
  • #3
i thought that clear flood mode was only with carbs...... since the injectors pulse based on the pip sensor.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
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Jun 29, 2004
#4
  • Jun 29, 2004
  • #4
D347643 said:
i thought that clear flood mode was only with carbs...... since the injectors pulse based on the pip sensor.
Click to expand...
as far as i know, flooring the pedal does cut injectors and allow raw fuel to be pumped out.
 
M

Mizark347

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Jan 21, 2004
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#5
  • Jun 29, 2004
  • #5
yes the plugs do seem to have some gas on em......no one has an answere for this?
 
M

Mizark347

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Jan 21, 2004
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Jun 29, 2004
#6
  • Jun 29, 2004
  • #6
If my timing is off....would it cause this problem?
 

jrichker

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#7
  • Jun 29, 2004
  • #7
Look for failed IAB (Idle Air Bypass). The IAB is used to bypass air around the throttle to control idle speed. The computer opens the IAB when you crank the engine to give it some extra air to start the engine.

Just for reference, here's a checklist for fixing starting 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 - look for 12 volts at the fuel injector red wires
E.) Fuse links in wiring harness - look for 12 volts at the fuel injector red wires
F.) Ignition switch - look for 12 volts at the fuel injector red wires
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. 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
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.
 

bln92cpe

New Member
Dec 15, 2003
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Los Angeles, CA
Jun 29, 2004
#8
  • Jun 29, 2004
  • #8
I have 42 lb squirters and my mechanic told me when i start it i need to floor the gas to get them spraying....It works everytime for me.
 
D

D347643

Banned
Jan 28, 2003
1,095
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0
portland, OR
Jun 29, 2004
#9
  • Jun 29, 2004
  • #9
wow thats a new one for me. thanks guys! learn something new every day
 
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