Silverado Fuel injectors

[drradon]

I have a '99 silverado with the 4.3 engine. When I first start it up in the morning, it will buck and stumble for the first 4-5 min of operation and then settles out and runs fine the rest of the day. I've tried fuel injector cleaner with no appreciable improvement. I've heard and read that the fuel injectors on these vehicles were poorly designed and tended to fail. I have seen advertising for replacement injectors and would like to get some advice:
1) Is this injector design prone to failure?
2) The dealer want's $800 to replace the injectors - but I'm not inclined to simply pay that amount of money to replace a bad design with another badly designed OEM.. Does anyone have any experience with aftermarket fuel injectors?

Many thanks.

[tallica_28]

i would first make sure it is the injectors.....when you say it bucks and stumble do you mean ruff idle? does it die on you?

[GMMerlin]

Originally Posted by drradon

I have a '99 silverado with the 4.3 engine. When I first start it up in the morning, it will buck and stumble for the first 4-5 min of operation and then settles out and runs fine the rest of the day. I've tried fuel injector cleaner with no appreciable improvement. I've heard and read that the fuel injectors on these vehicles were poorly designed and tended to fail. I have seen advertising for replacement injectors and would like to get some advice:
1) Is this injector design prone to failure?
2) The dealer want's $800 to replace the injectors - but I'm not inclined to simply pay that amount of money to replace a bad design with another badly designed OEM.. Does anyone have any experience with aftermarket fuel injectors?

Many thanks.

What has happened is quite possibly the poppets on the end of the injectors have stuck shut causing your misfire condition at cold start.
There is a procedure to unstick the valves (your GM dealer has the tools and procedure)
What happens is hydrocarbons build up on the poppet balls and cause them to stick inside the seats.
Now there is an updated injector assembly that replaces the old design and eliminates the poppets...if you are going to keep the vehicle for any period of time its worth the money to have the update done.

[drradon]

The engine seems to idle fine on a cold start. But as soon as I start driving - even with very gentle acceleration - it's clear that one or more cylinders aren't firing. If I let it idle - or drive it - for two or three minutes, it then runs fine and will continue to for the rest of the day. Next morning, same story.

[drradon]

Originally Posted by GMMerlin

Now there is an updated injector assembly that replaces the old design and eliminates the poppets...if you are going to keep the vehicle for any period of time its worth the money to have the update done.

Thanks GMMerlin - this sounds very much like the problem. Are these after-market injectors? I did take it in to the dealer a while back and they wanted $800 to replace the injectors - they didn't say anything about new design and I wasn't real anxious to chuck $800 on new injectors on a regular basis until I knew what the problem was. The truck just turned 50K - at the time, it was 30K - and I'm looking to keep it for as long as I can keep it running.

Can you recommend a source for these if they are aftermarket?

Many thanks again for the full story on the problem.

DT

[Arsenik111]

i have the same problem only it seems that i get it when i start the vehicle warm instead of cold and it idles rough after ive driven it for a while, if i have the same problem am i losing performance during driving?