How long do the stock injectors last? My car has over 100,000 miles on it and I'm troubleshooting the low rpm stumble... I've had a backfire or three in the last while and have reason to believe that my injectors might be going bad. Just curious if anyone knows the avg life on em

 

its possible you could have a bad injector but not likely. i would lean more towards the coil, coil wire, opti, plugs, wires, O2 sensor.

 

You also may want to check to see that none of your plug wires are arching. I would have your injectors cleaned.

 

Ive just replaced the O2's with no change, and not long before that had new plugs put in with no change either. I've popped the hood at night and looked for arching but couldnt find any (and you'd think it wouldnt only be at 1800-2000 rpm then as well).
So that leaves me with either injectors or the coil stuff. Would the coil pack only act up when the car is warm and at a specific rpm? Because to me it seems like the injectors would be the only thing that might do this @ a certain rpm.

again tho, does anyone know the average lifespan of the stock injectors?

 

Give us some more details about this "stumble."

 

Sure, only happens when the Car is warmed up. IT also happens intermettently, and seems to happen more often in colder weather. Bascially it happens when in overdrive and gradually accelerating. Once it hits 1800 RPM it stumbles until around 1900 or 2000 RPM. After and before that its just fine. By intermittent, i mean that sometimes its fine going between 1800-2000, other times if it stumbles (sounds like its missing a beat or having a hard time turning, total loss in power), I can slow down and accellerate again and it will usually stumble again. the cars gotta be in the right "mood" to do it. -=/ If i accellerate HARD, once it hits that rpm range itll do it briefly until its over 2000 rpm. Sometimes itll backfire (loud pop from the engine, its not the tranny mount because i know what that feels like).

 

When does it do it, straight from a cold start without stopping or only after you warm it up, shut it down and let it sit for a while. Like starting up going to a store, parking and shopping then come out and drive off then it stumbles. Know what I mean? This is important and can tell us a lot. While we wait for the answer, have you checked or replaced your fuel filter lately and I doubt this but have you checked your fuel pressure. I doubt it's ignition cause electrical things that leak so speek tend to get worse over time and less intermittant. Fuel problems can be wacky all the time.

 

Have you changed your plug wires?

Could be the coil/opti.

Does it miss near the redline?

Otherwise it could also be wires in the tranny shorting out.

 

Fuel filter was done very recently (3mo ago?). It only stumbles after the car reaches operating temp, i cant test the parking lot scenario because the problem is intermittent, but come to think of it i'm sure it has once or twice after going out to get something and drivng again. I don't have any thermostat mods done to the car.
I have not checked the fuel pressure.. Dont have access to the tools or a garage nearby =/ IT doesn't miss at high rpm and if the pressure was low woudn't the miss be at a higher rpm and/or not so "bang on" 1800-2000 rpm? Also it wouldnt matter if the car is warmed up or not i would thing too...

Oh, and the trannys getting rebuilt It took a dive just the other day =/ Should have the car back by tomorrow... so hopefully there aint no shorts...

Um.. Does anyone know what the average life for the stock injectors is? Thats all i really wanted to know...

 

I have had the same problem EXACTLY as you have now. My car has 170,000 miles on it. As of now my fuel pump is 1 breath away from the garbage. Hopefully the car will start up 1 more time to make it to my friends house. I'm also looking into getting a new fuel pressure regulator and pump as we speak. I also plan on changing the O2's and plugs. Please let us know if u find something out. I'm thinking of maybe a bad injector also or fuel pressure regulator

 

Also what brand of plugs did u use? I used Bosch Platinums and I have read ALOT of horror stories about them. I'm going to buy some AC delco's

 

WTF do you think the injectors do at 1800 rpm's that they don't do at 2500 rpms? There is no average life for the ball type fuel injectors. they use this type for its longevity. You need to answer some basic questions before you go tearing around shot gunning stuff. I had one that was getting air bubbles in the fuel line due to a bad connection at the fuel filter that occured after the car warmed up and then sat for a while. If the car was simply started and driven without the stationary time, the problem never showed up. I hope you find it what ever it is. Good luck.