Quote:
Originally Posted by skyphix
Its a little weird that it sounds on the verge of stalling at that RPM with a totally stock engine. Does it ever high idle when its cold? Or does it keep trying to find low idle?
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As for wanting to stall, if it's at 550RPM, it's okay except it will drop lower to the 350-400RPM range and then stall from there. If driving, then coming to a stop or slowing for a turn, it may just stall under the additional load. When you say cold, I will assume you mean engine cold. To that, I don't believe it ever high idles at all.
I should probably also mention that I assume it is a stock cam. I bought the engine used with 125K and just put new gaskets, seals, and externals like sensors and water pump on it.
Quote:
Originally Posted by skyphix
Have you checked your fuel pressure at all? Whats the fuel system setup?
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I have not checked fuel pressure. I have a hard time believing that the pressure could be low enough to cause an idle problem, yet accelerate with no issues. I stomp on it and it responds very well. Am I wrong in that assumption?
Running a stock pickup and tank from an 87 R10 and using a 96-97 Chevy P/U pump.
Quote:
Originally Posted by skyphix
I'd give the TB a more thorough cleaning. Not all I found felt sticking - but they all seemed to benefit from a good cleaning.
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Will do.
Quote:
Originally Posted by skyphix
Removing VATs and the rear O2's (disabling secondary O2 bank) really shouldn't cause this issue - even without O2's hooked up it should idle (mine did, just really rough.)
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This is what he was supposed to do. I'm not 100% sure that's what was done... he asked a number of things, all answers below. He's been doing these for years, so I anticipate that he's just got files he downloads quickly and that's it. Maybe he did the wrong one?
PCM Part #12200411
Drive by cable TB
5.3 from 2004 Silverado (based on dished piston)
2532_ _ _ _ fuel injectors (VIN Z)
2002 return style fuel rail
Case grounded O2s
Quote:
Originally Posted by skyphix
Do you have any exhaust leaks BEFORE the O2 sensors? What is the exhaust setup? Its hard to tell from the video but it does sound like theres quite a bit of exhaust leak. Might just be the video.
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I can get better video maybe Sunday from outside the truck so it'll be easier to hear. I'm running S10 swap shorty headers with true dual exhaust, no crossover pipe, with side exit. I'm not running cats and I have Flowmaster "glass packs". In my opinion, I don't think I have any exhaust leaks, but I had to drill out 5 of the header bolts and one of them had some minor thread damage, so I didn't want to torque it a lot for fear of stripping it out.
Quote:
Originally Posted by skyphix
What is your intake tract setup? Are there any modifications to the engine? Specifically, cam?
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Intake and throttle body is stock 2002 Tahoe. As far as I know, the engine was stock. I bought it used from a friend of the guy that owned the truck (he went to prison). As for cam, I can't be 100% sure.
Quote:
Originally Posted by skyphix
Yours sounds like its running rough through the whole RPM range that was in the video you posted... I know you checked for vacuum leaks, but if the cam it stock, it does sound like a vacuum leak. All the ports are plugged off on the TOP of the intake, correct?
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In my opinion, I don't believe I'm having any issues with how the engine runs under acceleration or even at a steady speed. As for ports on the intake, the only ones I'm aware of are the port for the fuel pressure regulator, the port in back for the power brake booster and then the evap canister purge valve, which I'm still running.