Can injectors burn out/up running too high duty cycle.They are electrical devices I would think they could damage somehow.

No.
What happens is that, if not given enough OFF time, they can get to the stage where they hang 1/2 open and 1/2 closed.
The fuel running past them helps to cool them some.
You can ruin the calibration, by running them dry. ie don't use good injectors on an ecm bench because you will ruin them.

I have seen injector coils go bad on rare occasion.

It is much more common for them to get clogged or stuck or leak somehow.

To check the coils you need just a digital voltmeter set to check resistance. For normal (saturated) type injectors about 14 ohms is normal - but anything over 12 is acceptable. For peak and hold (racing) injectors - which are NOT compatable with a stock computer - 4 ohms is normal.

Like I said - it is quite rare to have bad injector coils - but if you do it can cause all kinds of wierd stuff. It is easy to check - mite as well just to be sure.

?????
TBI injectors are nominally 1.25 ohms, and the TPI P+H 2.5, at least all the GM ones I know.

On the SEFI 148 some guys are running P+Hs with the stock drivers. Thou, it's been mentioned that adding a ground for the ecm case might be a good idea.

I disagree .. you can burn one out pretty easily if you keep it above 90% duty cyle most of the time. GM's are good upto 80% duty cycle.

Nope, not that I verify in controlled testing.
I have hundreds of hours of test time running various injectors on my ecm bench and just haven't seen that. At high DCs they run out of time to cycle and the're metering gets erratic, but that's it.

WOT on a typical street car only happens for a few percent of the time, there are other factors that would be more of an issue then 90% DC at WOT that would be the actual problem.

Anything is possible when it comes to electronics, however, if you go over the 80% duty cycle, it may not fry your injectors. They become static which means that they freeze up. too much input so they go static and ......get confused. but they easily reset. Anyhow, just my .02$

So you're saying an electric pintle like that can't burn from being run too fast... hhhmmmm..........

I'm not against you grumpy but would like you to stay open to new therory.There does'nt seem to be alot of research on the subject.I would also suggest an ecm bench cant simulate everything.I can just report what has occured to me.

"WOT on a typical street car only happens for a few percent of the time, there are other factors that would be more of an issue then 90% DC at WOT that would be the actual problem." grumpy

That is correct but I would argue that 90%dc can occur not only at wot.With prom burning I could set a 100%DC at idle if I want.Like me,my engine is a healthy 406sbc and am using 19lb injectors.I have ran 90%dc under moderate throttle just before the fp regulator raises the psi.Running too small injectors can exceed 90%dc under various loads in some lager displacement/high hp engines.

The logic behind my post is the injectors would start to take on heat @ high DC over time.If my injectors are way too small then on long drives @ high DC they could be damaged.Is'nt there springs in injectors?We all know spring can get tempermental.

Grumpy is posting actual data. If you disagree, go out and do some testing and come back with data disproving him.

People bringing "I heard..." info and presenting as fact kinda annoy me. Grumpy bringing "I tested..." info is a good thing.

You're invited to keep your disagreement with his communication style to yourself.

Grumpy did'nt post any actual data,testomonial yes.Futher more he was refurring to wot and duty cycle.I am talking under various driving conditions.As far as the "what I think" crap,I stated "this is what I have experience." Finally I did tell grumpy thay I agree with what he has said.As my consern is not wot/DC but running too small injectors and the effects of duty cycle.The truth is that nobody here has tested new injectors spray pattern and flow vs an injector exposed to 100% duty cycle for x ammount of time.So I guess speculation is part of therory,for now. BUT I would think that its possible to have an adverse reaction to being exposed to 100%DC for X ammount of time.

First off you can't get an engine to run at 100% DC with 19 lb/hr injectors, on a 406 at any reasonable FP.

You really need to take a serious look at what your saying.

On a normal car your looking at a PW of 2 msec at idle. At 600 rpm you have run a PW of 100 msec to be at 100% DC. That's 50x times as much fuel. 50x.

There is a difference in hammering a pintle vs fring the coil, two different subject matters all together.

I have run the bench for hundreds of hours trying to destroy ecms and injectors.

If you want to comment fine, but tring to *agrue* with facts is silly. If you doubt my results build a ecm bench and try things out for yourself, but just guessing aloud gets you nowhere.

I asked the question here,Iwas'nt trying to argue,I was just defining my question,no need to get mean.There was a bit of misunderstanding here .Instead of making my finger tired and type in my clarifcation,I will just use the infomation posted as it is sufficient.

Injectors DO fail. For the most part, what I have ACTUALLY SEEN is the windings in the injector break down. This causes a short/open in the injector, and resistance goes either way down, or is infinite.

A completely failed injector (open circuit) will simply give you a miss. An injector that is breaking down (reduced resistance) will cause all sorts of interesting driveablitly problems. Since this is a batch fire system, one bank of injectors are all on the same ciruit, one injector having a significantly lower resistance than the rest will allow an easier path for the current to follow, so one injector will pulse REALLY well (the bad one....) and the other three will give a significantly reduced "shot".

Age is a real killer of injectors. Consider the environment they live in. It is hot, they get wet, etc. Not a real pleasant place to be.

As for running at a high duty cycle causing failures, I have no data on that, but, I would think that the injector would behave as the folks have suggested, but, I do not think it would cause permanant damage.