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Hey man. That’s a throttle body fuel injected v6 first off, unless the truck’s been modified. I’m also suprised to see the V6 in a 3/4 ton. Moving on. There should be a ‘stove pipe’ coming off the exhaust manifold that leads up to a ‘choke plate’ built into the intake assembly (inside the metal piping inside the filter housing). Make sure that ‘choke plate’ isn’t stuck open. It’s job is to operate similar to the choke plate on a carburetor. If it’s stuck open, it’s giving too much air when the vehicle is cold. Also, I would check for vacuum leaks in general. Here’s Eric’s vid:
http://www.youtube.com/watch?v=9CPqbaSgcok
Good luck man.
I have looked at that and I believe one of my problems is in the fact that when it’s idling the choke plate is shut completely from what I could tell. I can manually hold the throttle on the side and open the butterfly a bit and it seems to idle fine..and yes..i know..idk what Chevy was thinking when they decided to throw a V6 into a V8 frame..Will be replacing it with a 454 big block when I can find one..lol..but for now gotta fix this problem..
P.S. makes more sense..I was trying to find the idle screws and they are non-existant..(used to working with carbs. not Fuel Injected..I’m old School) lol
and also there is absolutely no vacuum system on the truck at all. That was one of the first things that popped into my mind.
Well, there is a vacuum system on every engine. If you have power brakes or cruise control for instance, there are vacuum systems. Neverminding that, an intake leak will cause a vacuum leak. Also consider that the EGR runs into the intake (another possible leaking area). I’m just trying to explain that you should still check for vacuum leaks.
When I open the hood I do hear what sounds like a bad vacuum leak..I suppose my knowledge on this stuff is still in the process of it..I will check it out and see if I can find out where the noise is coming from. you might be right as I have not checked the EGR valve. Was not meaning to sound like I was “calling you out” or anything..I am writing all of this down on the things to check tomorrow when the rain lets up lol
You’re fine bro. I didn’t take any offense. If you hear an obvious ‘whistling’ vacuum-leak type noise, then that may very well be yer problem. I want to add, even tho Eric went over it in his video, that if you plan on using the ‘carb cleaner’ method to check for said leaks, please have a fire extinguisher handy. Safety first!
Also, check around the baseplate of the throttle body, along the intake etc. Don’t specifically focus on the EGR system. It might even be something simple like the brake booster line for instance. Good luck man.
oh noo! I don’t use that method..Caught another truck of mine on fire in the past..did have an extinguisher handy thankfully. but I manually go over it nowadays..lol
It does sound like a vacuum leak issue, in fact that engine is famous for intake gasket leaks which will cause all kinds of problems. I understand your fear of using carburetor cleaner but you can also safely use propane or you can coat the suspected areas in soapy water and run compressed air into the intake and look for bubbles, or you could even use smoke to find them but based on your description I’d be looking for a vacuum leak somewhere.
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