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Fuel injectors

1375 Views 13 Replies 3 Participants Last post by  kennethbryant903
I have an 07 mustang 4.6 I had a p0202 code and replaced the #2 injector. Then I had a p203 code so I replaced the rest of them. Now I have a p0202, p203, and a p303 code I would appreciate any advice
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What kind of shape is your battery and charging system in?
Sometimes a failing battery or alternator (diodes too) can cause issues with the PCM.
Also check and clean battery terminals and grounds along with the ground strap from the engine to body or battery.
Could have gotten a faulty injector or 2.
One thing I do is I'll unplug whatever injector while it's running and note any difference in rpms.
Another thing is I'll swap out a known working injector like #1 with #2 and see if anything changes.
If it stays the same on codes and the way it runs, then the problem is with the connection either at the injector and/or the circuit supplying it.
If the code changes to show #1 is bad and #2 is good, then the problem is likely with the injector. You can do this with the #3 as well.
I'm leaning towards a poor connection somewhere, i.e. a bad ground. This is where a volt/ohm meter comes in.
The P303 will likely clear up once you get the the other codes taken care of.
Good idea to check out with a noid light .
Don't have one of those...yet, still doing it the old fashioned way.
May just have to get one. Bet it makes testing much faster.
Left side no difference unplugging any injector. Rt side lots of difference
Check your connectors. R.S.Logans' (#7) post above yours is a cheap easy way to do it.
You may have gotten a bad batch of injectors.
I would try a few of the old known working injectors. Also, make sure your coils and plugs are firing.
Power to all 4 on Left side by test light not sure how that 194 works
It's also known as a poor mans noid light. You take a 194 bulb like the one below, commonly used in older cars in the instrument clusters and marker lights, straighten out the terminals so they can contact the inside of an injector plug. Like using a test light but a little easier.
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