Hesitation

Rod Diagnostician California Posted   Latest   Edited  
Tech Tip
Driveability
2012 Nissan Versa 1.6 S 1.6L (HR16DE)

Part throttle to ¾ hesitation, no codes , almost felt like a cvt issue.

passed volumetric efficiency test ( liter times 40 in grams per second)

long term fuel trim at part throttle was -17 , rear o2 read .1v.

this meant front air fuel ratio sensor over reporting 

replaced front air fuel ratio sensor , long term fuel trim zeroed out and rear o2 went to the magic number of .7 v.

hope this will help some one 

happy holidays .

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Thanks
Darren Technician
Wisconsin
Darren
 

Tailpipe readings with a 5 gas would have been interesting…..

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Stuart Mobile Technician
Illinois
Stuart
 

What were the #s at idle?

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Marko Technician
Ontario
Marko
 

During the part throttle what was the reading on front oxygen sensor? Thanks for the write up

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Steven Mechanic
Washington
Steven
 

…passed volumetric efficiency test ( liter times 40 in grams per second) I've never heard of that rule of thumb. Here's a screenshot of some known good values. It looks like the real world data is fairly different than using that rule. Would you agree?

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Geoff Diagnostician
Hawaii
Geoff
   

Steve, SMP teaches it. Actual rule is, supposed to see minimum 40X engine size at WOT at 5000 rpm. Your screen shot doesn't have the required info to compare/contrast the teaching. Since SMP teaches it I suspect it comes from JW (of GM and iATN fame) since he runs the course content over there. Non turbo of course.

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Steven Mechanic
Washington
Steven
 

Ok. I’ll have to check more data to see if that’s a useful rule. It’s at least a ballpark guess, but nothing to use as confirmation. If you combine it with a few other tests, then that can increase your confidence in some diagnosis situations. Thanks.

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