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Discussion Starter #1
I am looking at a 2003 Chevy 3500 with a duramax, it has 160,000mi and the salesman thinks it has original injectors, he also said it has a "Slight miss" but it still runs good, and the miss is mostly noticible when it is cold, he is asking 13,995 and it is in amazing shape, it was used to tow the Dale Jr. show car around so it was well taken care of I would assume, and it comes with a super-chips tuner, but my main question is what do you think the cause of the miss is? just bad injectors or what?

here is the truck

2003 CHEVY DURAMAX 3500 CREW 4X4
 

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an injector taking a shit would cause it to skip if it's that bad.

car salesmen are a different breed of people, if their lips are moving they are lying. get a balance rate test done on it if you wanna pursue it. if the injectors come back good have a reputable diesel tech diagnose it
 

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Discussion Starter #4

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Well it depends what he calls a slight miss? it could just be the FPR being a dildo and surging, one would have to hear it tho, salesmen are tards usually. Also like the other guys said, get the injectors tested.
 

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Well it depends what he calls a slight miss? it could just be the FPR being a dildo and surging, one would have to hear it tho, salesmen are tards usually. Also like the other guys said, get the injectors tested.
What is an fpr? a family friend owns an auto repair shop, I may have him come along to look at it, do you think a regular snap-on diagnostic tool could check the balance rates and the fpr?
 

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I bought an Edge Insight mainly for situations like this. Just plug it in and all questions resolved.
 

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FPR = Fuel Pressure Regulator, it makes mine sound like a miss when it's cold, it's not a miss tho, it's just varying the pressure cuz it's fukked, doesn't hurt anything lb7's are famous for it.

I have no idea on the snap on scanner.
 

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Snap on solus, solus pro, modis, and veers will read the balance rates for sure. Not sure about any of the other snap on scan tools.
 

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*verus not veers
 

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For when you go check it out, the balance rates you're looking for are +/-4 in park and +/-6 in drive
 

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Discussion Starter #14
For when you go check it out, the balance rates you're looking for are +/-4 in park and +/-6 in drive
Ok do you mean +/-6 in drive while it's driving or just stopped in drive?
 

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you'll want to have the truck up to operating temperature and then test it in park and in drive at idle
 

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here's the exact instructions from gm for checking balance rates:

Start and run the engine until the engine coolant temperature is more than 82°C (180°F).
Turn OFF all accessories.
Hold the brake pedal in the fully applied position. A hiss will be noticeable when the brake is fully applied.
Place the transmission in Drive.
Idle the engine for more than 30 seconds.
Record the Balancing Rate Cyl.1-8 parameters from the scan tool while the engine is at idle speed.
Repeat steps 2-6 with the transmission in Neutral.


The balance rate adjustments are utilized by the ECM only at idle. The balance rates are the fuel adjustments for each individual cylinder based on the variations in engine crankshaft speed. A positive value indicates that fuel is being added to each cylinder event, such as with poor engine compression or a fuel injector that is not flowing enough fuel. A negative value indicates fuel being removed from each cylinder event, such as a fuel injector that is flowing too much fuel. The balance rates will change depending on if the transmission is in Neutral or Drive.
 

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Discussion Starter #17
Thank you
 
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