So I got this 454 that's I had rebuilt and has around 2k miles on it. Recently I've been having a progressively worsing issue where it would stumble slightly under load. It's now to the point where it stumbles at idle and there's no getting it to run smooth while driving. Thought it was tps, replaced it nothing changed, replaced the fuel filter no difference. Tested the coil it's fine. Has new ceramic boot plug wires due to me melting the stock ones constantly. Has a new cap rotor and plugs from rebuild.
Greetings 95 obshitbox,
Welcome to the GMT400 forum! Not only will you find a lot of shared enthusiasm for these
old warriors from all over the world, you will also find a whole lot of Texans in here.
I'm going to infer from your username that your 454 is a TBI setup, but the more you
share about your ride the more productive our remote troubleshooting will be.
(Engine, trans, pure stock, what mods, etc.)
No doubt that the pros in here will want to know what fuel pressure is being seen
by your TBI (?) setup, for sagging fuel pressure is always at or near the top of
the suspect list when troubleshooting a stumbling/won't take the gas issue.
In addition to the fuel pressure info, I would be interested in *when* the stumbling
occurs? Do it occur 100% of the time, from 1st cold start through the rest of the day?
Or does it run OK when cold, and then degrades once it's fully up to temperature?
(This would be a scenario where a good engine {running Open Loop} is the victim of a bad
feedback loop due to a funky O2 sensor once the engine is all warmed up.)
No doubt that this can be figured out, especially the closer to stock that your engine bay is.
And a cheerful heads up that folks will want to see photos of your ride. Including the engine
bay. It seems to be the currency of this forum.
So go ahead & share all the times that the engine runs well, as well as when the engine is
being balky. A lot of times a small detail will give us a big clue.
Sounds like a nice truck. A big block truck is about as good as it gets. Especially when they are
running right. :0)
