1999 Tahoe VCM/PCM help needed

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TowinTahoe

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Hi to all. I am new to this forum. I have a 1999 Chevy Tahoe with the 5.7 Vortec with over 283k miles on it. I have owned for over 2 1/2 years and a couple months ago, I began experiencing some rough idle issues. I have replaced just about all electrical components based on a crank/no start issue. There is compression and the fuel pressure is good. ther is no spark. I have just left the mechanic shop in Norfolk with the same conclusion as the mechanic in SC where I first broke down that the issue is no voltage signal coming out of the PCM/VCM computer. What I would like to know is if I purchase one from ebay or another supplier, is there a way to bypass the reprogramming or reflash of the computer? I am an active duty sailor, so any help here would be greatly appreciated.
 
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TowinTahoe

TowinTahoe

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An update: Well, after being charged $95 to fix a bad screw on the distributor and still no start, I went on ebay and ordered a PCM/ECM computer that is already programmed, after I supplied the VIN. After doing the procedure for the truck to learn the computer, it started right up, but with a clanking noise from the distributor. took it back to the mechanic to fix the issue, and was told that a new distributor was needed. and that if i were to buy it, they would install it for free. hmmm, red flag there. BTW, when I got back to my house, less than three miles away, it died right when i put it in park and wouldn't start.

I went and bought a new distributor, got it towed back to the mechanic, and they installed it, but still, no start. They said there was no signal coming from the computer again and recommended another place that deals with electronic issues, to fix my truck. I called the computer place from ebay that supplied me the first PCM/ECM and got another one sent to me. I just did the same procedure and still, no start. I am just losing it right now. can anyone please help? I'm in Norfolk, VA
 

TigerEyz3

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For our trucks, the distributor has to be within +/- 2* for the computer to manage it. To get "close enough" you need to set the #1 cylinder to top dead center (TDC), then you can point the rotor pointer to that position and drop the distributor in place. From there, you can determine whether the rotor needs to be moved forward/backward so that drop-in occurs on the correct tooth of the distributor gear. Once the gear teeth are in the right area, you then have to have a special tool to get the timing within the +/- 2*....at which point you can lock down the distributor.
 
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