Replacing injectors?

[Degnol]

I have had several problems, intermittent, with the code for "misfire, cyl #4"
I think it is the injector. Does it ever make sense to replace just one? Or should I replace all of them?$$$$$
This is a '98 350 Vortec in a Yukon with 125K on it.

I don't know dick about fuel injection, so forgive my stupidity.

Thanks,

Ed

 

[Mace]

try one first, it is possible the conections are bad as well.

You can also pull the injector and add power to it to see if it is opening properly.

Stupid simple way of telling is to pay attention to the "click" when it opens. IT shoudl be a very sharp sound.

Or, you could get yourself a sonic bath off of ebay. then just clean the injector yourself..

 

[ellington12]

degnol,

if i'm remembering correctly the injectors on that motor are located inside the intake manifold and replacement requires removing the upper intake manifold. these injectors are sort of known for being problematic. if you do in fact have a bad injector i'd replace them all. however, if i'm suffering from brain fade and you have injectors that are mounted external to the manifold, then i'd say you could replace just the one injector.

if you've already done this then please ignore for i by no means mean to insult your intelligence. have you swapped plugs with another cylinder to see if the misfire follows the plug?

 

[Degnol]

At 100K I had the plugs replaced with the GM, uh, Platinum? plugs, new cap, wires, etc. The "check engine" light came on within the next 1,000 miles and the garage replaced all the wires and the #4 plug. Same thing happened 3-4 times and plug was replaced, or wires or both. I ran a can of SeaFoam through it and it went away for 15K. That's why I lean toward the injector.

If the intake has to come off, I'll let the real mechanics deal with it.


Mace, if you mean an ultrasonic cleaner, I have three. Normally used for cleaning dental instruments, but on the weekend Should I clean it with some SeaFoam or Techron or???? That is assuming I can get to it and remove just the injector.


Thanks for all the replies.

BTW, I never felt a miss or loss of performance, just a code reading.


Ed