Injectors are not injecting!! Why???
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New User
Joined: Jul 2002
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Injectors are not injecting!! Why???
My truck won't start!!! 88 F150 5.0 HO block.
There is pressure in the fuel rails, truck turns over fine, firing order is correct, timing is correct.
when attemping to start...acts as if there is no fire. i checked the plugs after trying to start...
they were dry. it seems to me that the injectors are not injecting!!
What could cause this??
oh..the injector wiring harness is plugged in and grounded. i don't know what else to look for.
Thanks for all the info.
Jared PSU tailgater
There is pressure in the fuel rails, truck turns over fine, firing order is correct, timing is correct.
when attemping to start...acts as if there is no fire. i checked the plugs after trying to start...
they were dry. it seems to me that the injectors are not injecting!!
What could cause this??
oh..the injector wiring harness is plugged in and grounded. i don't know what else to look for.
Thanks for all the info.
Jared PSU tailgater
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Injectors are not injecting!! Why???
Try posting that question here.
http://www.ford-trucks.com/cgi-bin/d...ID76&conf=misc
http://www.ford-trucks.com/cgi-bin/d...ID76&conf=misc
Injectors are not injecting
Senior User
Joined: May 2003
Posts: 455
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From: Alaska
The computer grounds the injectors to fire them, the computer is grounded at the negative battery terminal.
You can see if the injectors are firing with a noid light, lacking that, you can back probe an injector plug with a voltmeter or test light.
In cranking mode, one side of the injector will be a steady 12v, the other side will blink, if you have voltage on both sides and it does not blink, the computer is probably bad, if you have no voltage, check the fuses, EEC relay and wiring.
You can see if the injectors are firing with a noid light, lacking that, you can back probe an injector plug with a voltmeter or test light.
In cranking mode, one side of the injector will be a steady 12v, the other side will blink, if you have voltage on both sides and it does not blink, the computer is probably bad, if you have no voltage, check the fuses, EEC relay and wiring.
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Enjoy FTE....and
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From: Virginia
The first thing I would do is pull a plug wire off, stick a screwdriver up in the wire, and while holding the screwdriver by the plastic handle, get someone to crank the truck while you have the metal part of the screwdriver very close, but not touching a piece of metal on the engine block. You should get a nice blue spark.
If you don't get a spark, the next thing I would do is pull the distributor cap off, and while cranking the motor, make sure the rotor is turning. This is really important for the six cylinder guy, since I have heard of two of these engines now, stripping the teeth on the timing gear(it's phenolic material).
If the rotor is turning, but you still have no spark, I would try the ignition module mounted on the dist. The module sends pulses to the computer to let it now when the engine is turning and also timing info. If there are no pulses from the module, then the computer is not going to fire the injectors.
If you don't get a spark, the next thing I would do is pull the distributor cap off, and while cranking the motor, make sure the rotor is turning. This is really important for the six cylinder guy, since I have heard of two of these engines now, stripping the teeth on the timing gear(it's phenolic material).
If the rotor is turning, but you still have no spark, I would try the ignition module mounted on the dist. The module sends pulses to the computer to let it now when the engine is turning and also timing info. If there are no pulses from the module, then the computer is not going to fire the injectors.
