Fuel Injection Not Functioning
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Fuel Injection Not Functioning
Hi. I am trying to get the injectors in a 1989 Ford F250 with a 5.8 automatic to work. Someone previous to me was doing some cutting and splicing to the harness without really knowing what he was doing. I have it just about patched back together now. The fuel pump relay works, eec relay works, I have spark, the 2 injector banks have 12 volts. The problem is the computer is not grounding out the injectors. What sends the signal to the computer to fire the injectors? I won't rule out a bad computer, but this would be rare. Any thoughts would be appreciated. thanks.
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From: Easton,Ks
Check the small black wire with a green or white stripe on it coming off the NEG post of the battery. This is the ground wire for the EEC Computer.
The PIP signal is what tells the Computer when to ground the Injector banks.
The PIP signal is what tells the Computer when to ground the Injector banks.
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From: Ottawa, Ontario
Originally Posted by subford
The PIP signal is what tells the Computer when to ground the Injector banks.
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Thanks for the replies. I see the PIP lead coming off the module that is mounted on the distributor. This lead has continuity going to the PIP pin on the computer plug. The computer has 3 grounds. One is the case ground (functional), two others are 'Batt' grounds according to the manual I have. Bolth of these are black with a green tracer. These 'Batt' grounds did not actually have continuity to ground, so for diagnostic purposes, I grounded bolth of them. The computer also has power coming in at 2 pins which I confirmed. If I were to try to verify that I have a PIP signal, how would I go about it? Is there something I am overlooking? If I am getting a spark (which I am), should I assume the hall effect is functional? Thanks
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From: Easton,Ks
Originally Posted by fleetboss
Bolth of these are black with a green tracer. These 'Batt' grounds did not actually have continuity to ground, so for diagnostic purposes, I grounded bolth of them.
Originally Posted by fleetboss
The computer also has power coming in at 2 pins which I confirmed.
Originally Posted by fleetboss
If I were to try to verify that I have a PIP signal, how would I go about it?
Originally Posted by fleetboss
If I am getting a spark (which I am), should I assume the hall effect is functional?
Here is a diagram showing the power inputs of the EEC.
The wave forms from a scope.
And one of the Ignition system.
Last edited by subford; Jul 17, 2007 at 11:53 AM.
