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2014 Chevy Silverado
Platform: Truck, GMT 400, 800, & 900

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Old April 16th, 2009 | 10:09 PM
  #11  
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Yea just get somebody to check it out. When you get stumped, the expensive tools have to come out.
Old April 17th, 2009 | 12:27 AM
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Originally Posted by MDTAHOE
That is only a scanner for codes and maybe data. A scope is a oscilloscope, it picks up the ignition pattern to look at the firing line
and kv. Also a 5 gas analyzer to look at the emissions. Our 5 gas analyzer was 13,000 dollars. And our oscilloscope with a 5 gas was over 20K
My bad... Misunderstood his post.
Old April 17th, 2009 | 7:04 AM
  #13  
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A couple of minutes to go zero? When you turn the key off it should stay stable for a while then very slowly fall some but not to zero
Old April 17th, 2009 | 3:54 PM
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oh what would cause this? i already fixed the leaks and it has a new TBI gasket all new o ringsd and nylon washers, and a new fuel pressure regulator. it wouldnt be the fuel pump would it? its been going on or a year seams like it would of died by now.
Old April 17th, 2009 | 9:38 PM
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With your pressure gauge attached you need to pinch the return line closed I think there is a rubber section by the tank if there is no rubber section you need to tie one in (it must not leak). Cycle the key pressure should go much higher then before if not the pump is bad. Watch the pressure if it does not fall now then your leak down is the regulator. If it still does then it is the pump or injector. To find out which one you need to cycle the key and quickly pinch the pressure line ( this will require 2 people, 1 for the key and one to pinch).If the pressure holds you need a fuel pump. If it falls off your problem is an injector. Also remember just because a part is new it does not mean it is good never assume so. You really need to find someone in your area that is qualified to trace your problem down. Without actually seeing the truck I may not be able to help you. Call around and ask shops if they have a 4 or 5 gas analyzer and ignition scope. If I actually saw the gas bench readings I would know for sure if it is a fuel problem. Do you have a scanner that shows the sensor data?
Old April 17th, 2009 | 9:44 PM
  #16  
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I just re read your post this is a tbi truck? You say it has a new pressure regulator? Who took the T-body apart to put it in? Every t-body I have ever seen that someone took apart and messed with was no good anymore. Especially if that person really did not have much experience. You may need to replace the t-body with a used one or better yet a remanufactured complete unit
Old April 17th, 2009 | 10:25 PM
  #17  
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If you decide to go to a shop with the equipment post the emissions results and I will see if I agree with them before you purchase any repair. Tell them you want readings for HC, CO, CO2,
O2, and the air fuel ratio at idle, 1500 and 2500 RPM. If they have a ignition scope see if they can print the pattern and you can fax it to me. Also ask if their guy doing the tests is ASE L1 certified
Old April 17th, 2009 | 10:58 PM
  #18  
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this is actually the guy who owned the truck before he is GM certified and works at a chevy dealer he is doing it for free just because he used to own the truck!! I appreciate your help so much! I will Pm the results to you i am having it looked at monday morning. How do you think the throttle body is ruined? I followed my hanes manual the injectors only go on one way and you will here a click the fuel pressure regulator will just bolt on. Will these results tell if it is bad fuel pump? hoiw does it work? the guy said 90 percent chance it will find my problem thanks!!!
Old April 17th, 2009 | 11:03 PM
  #19  
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It will not tell if the pump is the problem but it will tell if it is a fuel problem. I will be able too see if it is running lean or too rich causing it to load up at lower speeds.
You must disassemble it to do the regulator. Take a look at this link.
http://chevythunder.com/gm_throttle_...ction_pg_1.htm

Last edited by MDTAHOE; April 17th, 2009 at 11:06 PM.
Old April 18th, 2009 | 2:31 AM
  #20  
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i already replaced the regulator. what does the fuel meter do? could that be the source? How come when i put my stock chip in it throws an error code? Do you think i should put my stock chip in and maybe this will fix it? Thanks for your help ive really been nedding somone like you to talk to!!

Last edited by suzuki-guy; April 18th, 2009 at 2:36 AM.




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