hi i guys my mechanic was fighting this problem for almost 2 months and he can't find a problem.he did checked everything and everywhere as well as replaced an injector.

ok i have a 2004 ford freestar cargo van 3.9L Automatic


Throwing a code for open injector #4. OMG my mechanic is the best one ! But he can't find a problem !!! He check pretty much everything and still can't find a problem

Any suggestion ?

Thank you

:PS check a compression and it's good )

 

Hello Alex,
When you say open injector it could mean at least two things.
Is it staying open and allowing extra gas to go in or is the electrical circuit to the injector open causing the injector to not open when it is supposed to. If possible give us the code # it is showing.

 

Yes it was saying open circuit injector :-/

 

Open Injector circuit #4 would be the P0204 code.

Sometimes I tend to go right to the hard stuff and forget the simple things to check at times...Bang my head against the wall for a while...Then go "Dang it"..Should have checked that to begine with and saved all kinds of head banging...

Has he verified power and grounding to the injector? Also has he verified return voltage to the ECM unit? Injectors have a +12vdc at all times to the injector normally thru a relay and the ground is pulsed ON and OFF thru the ECM. The ECM also monitors for a +12vdc return on the ground lead back to the ECM. When the injector is activated, the +12vdc flows thru the + side of the injector coil back to the - side of the injector coil, then back to the ECM. Even though injector 4 was replacede, has he tried rolling it with another one in the vehicle to see if the problem moves or stays?

An operating injector needs 4 things.

1. +12vdc to the injector
2. A good - lead back to the ECM.
3. +12vdc back to the ECM on the - lead when the ECM pulses the injector - lead.
4. An ECM that is actually pulsing the injector - lead and seeing the +12vdc on the - lead when pulsed.