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Injector hell

One day the car was fine. Next day I go to start it and it had the shakes, big time.
AAA’ed it to the dealer, they told me that 3 injectors were bad (V6 engine). All at the exact same time, all 3.
I was told that it is common for injectors to fail in groups. Why?? They are in separate chambers. How can this be?
The dealer recommended that I also replace the other 3 injectors as a preemptive measure, since they are at risk of failure.
What’s the deal with injectors?

The reason they sometimes fail in groups is that injector manufacturing is a highly automated, very well controlled, very consistent manufacturing process. Each is almost exactly the same as the one before and the one after. Ergo, their lifespans can be remarkably similar.

I agree with the dealer that you should change the others too. I would have suggested that too. You can expect them too to be at the end of their lives.

It’s hard to say?

Since you don’t provide the year, make, model of the vehicle, for all we know there could be a Technical Service Bulletin that involves a problem with the injectors on said vehicle.

Tester

Another reason for groups of injectors to fail is debris contaminating the gasoline supply , if it gets passed the fuel filter, or the source of the debris is post fuel filter, can clog any number, including all, of the injectors in a brief time. Did you purchase gasoline at a different gas station than you normally use in the past few fill-ups?

Did you have all 6 replaced & did it solve your problem ? Did the dealer replace or recommend replacing any other parts ?

Year, make, model, and engine size please.

I’ll defer to the experts but I have never had to replace an injector. (120K, 350K, 520K, etc.) Now when I was at the GM garage way back though with a sticking injector, the mechanic pointed to a Vette in the next stall that he said needed three injectors. Said the owner was not going to be pleased. I guess I’d listen to the mechanic depending on what they cost. If its the $60 variety, its not much more labor to replace the other three at the same time.

Had a 98 or so gm truck, mechanic could not figure it out, sent to the dealer, fuel injector, there was a recent post about problems, After numerous ages I suggested fuel injector, it happens sometimes http://community.cartalk.com/discussion/comment/3175929#Comment_3175929

Bing, if the injectors on that 'Vette were as hard to access as some of the horror stories I’ve heard, I can understand why the owner wouldn’t be pleased.

It WOULD be interesting to know the year, make, model, & engine of the OP’s car, as ASE requested.

I’d find it strange that 3 injectors failed. Depending upon the type of vehicle maybe the power source for the injectors is split in half with one circuit powering 3 injectors and another circuit powering the remaining 3. If a fuse lets go 3 of them die. It should be very easy to diagnose.

My Mercury was wired this way.

I’d replace all of them IF those 3 are legitimately bad but I’m a bit antsy about the diagnosis.
What happens if they replace all 6 and the same problem exists? You really need to be on the same page with the dealer about the “what if” part of this problem.