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1994 Chevy G30 engine trouble..

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Old Apr 11, 2018 | 4:30 PM
  #11  
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Not familiar with that, could be though because I had some vacuum issues in the beginning. Do you know what that would be called?
It idles perfectly all day long and revs strong and smooth in Park and neutral. It’s just when you put it in drive all the fun starts..
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Old Apr 11, 2018 | 4:59 PM
  #12  
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I only know how it works in principle, not if you have it or how it's implemented. It's simply called vacuum advance, and you would see a vacuum tube going to your distributor. Mechanical advance also exists, and I think it used centrifugal weights.
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Old Apr 11, 2018 | 11:13 PM
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Vacuum advance, which advanced the timing when you punch it, not as much under normal accel...
Your engine likely has it. I think it was used right up to the vortec engines...
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Old Apr 12, 2018 | 9:04 AM
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I checked on distributor this morning and no vacuum lines going to it. Plus the van has a Vortec engine, it says it on the valve covers, so I’m thinking that’s all controlled by ECU on these? Thanks
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Old Apr 12, 2018 | 4:14 PM
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Have you scanned for trouble codes?
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Old Apr 13, 2018 | 6:52 AM
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No I haven’t read codes in a while. I have a code reader but it’s a crappy cheap one with the 3 red lights and it’s really hard to figure it out. I’ll try that today
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Old Apr 13, 2018 | 11:20 PM
  #17  
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Gotta be a sensor. So many to choose from....throttle position, camshaft position, crankshaft position, mass airflow, etc. You need a proper code reader.
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Old Apr 14, 2018 | 2:51 AM
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I agree. I’ll have to order one tomorrow. It can’t be too much harder to find now, there are only a handful of sensors left I haven’t already replaced!
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Old Apr 15, 2018 | 11:21 AM
  #19  
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So I’ve tried a lot of other things today, unplugging sensors etc and test driving.. It seems to drive almost totally normal when cold, but as soon as it’s up to op temperature it runs like crap.. popping spluttering no power and almost like it’s constantly in overdrive. The other weird thing, when it’s cold and I’m driving it, it’s like the transmission is shifting backwards?? It will shift into lower gears when you slow down and higher gears when you speed up... Has to be a trans issue as well surely?
Anyone want to buy it? I think I’m at my wits end!!
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Old Apr 15, 2018 | 8:46 PM
  #20  
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Did a shop do the rebuild? Maybe they will look at it for you.
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