# 94 HB TB cleaned-ECU Reset Low mpg- drive hard or easy



## nissantruckreps (Feb 1, 2008)

I cleaned the TB. Gas mileage dropped without resetting the ECU. I disconnected the battery for 40 minutes and hit the brake. The gas mileage is still low after 50 miles. I drove it hard at times. Should I drive it easy or hard after ECU reset to give it a range of conditions for relearning for best mpg?

It runs and idles- fine -has plenty of power. 

No codes showing- but maybe they dont show until at least 100 miles?

94 Hb 2wd 5 speed 4 cyl

Thank you,


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## TheRepairMan (Jun 30, 2009)

It shouldn't matter, but if you expect better mileage you have to drive it easy all the time. It's not a very efficient engine either way, though.

Don't know about the 100 mile thing. I don't believe it has to complete a drive cycle like all newer models, but if there's a hard fault the light should come right back. 

~R


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## jp2code (Jun 2, 2011)

> The gas mileage is still low after 50 miles.

Like what? I've got the VG30e. If my starts are very slow and smooth, I can get about 20 MPG. If I just stomp the gas and go, I get around 15.

The KA24e should be getting around 24 MPG, unless you have monster tires on there.

I'm not sure if disconnecting the battery while pressing the brake pedal clears the codes or not, but I know going into Diagnostic Modes IV or V (4 or 5) and turning off the Key will.


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## TheRepairMan (Jun 30, 2009)

jp2code said:


> > The gas mileage is still low after 50 miles.
> 
> Like what? I've got the VG30e. If my starts are very slow and smooth, I can get about 20 MPG. If I just stomp the gas and go, I get around 15.
> 
> ...



I got about 24mpg on mine before they started the whole methanol/gas thing. It went down at least 10% using the blends. All my vehicles did. Ugh!

-R


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## smj999smj (Jan 1, 2006)

The computer self learns to the driver's driving style, so just drive as you would normally. When you erase the self learning, it puts the ECM back to it's base settings, which is different from older GM's where you had to perform a relearn procedure. 24 mpg is probably a little optimistic as that was the highway rating for them when they were brand new. Combined mileage was usually around 21-22 mpg and you might see a little less now that it has 20 years of wear and tear on her.


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## Deerhurst (Jul 25, 2011)

jp2code said:


> > The gas mileage is still low after 50 miles.
> 
> Like what? I've got the VG30e. If my starts are very slow and smooth, I can get about 20 MPG. If I just stomp the gas and go, I get around 15.
> 
> ...



Haha! 15 being low. On the highway I get good mileage for a V6, 24.5 of all highway before the headers. With stock everything it was able to drink up 8 gallons in less than 75 miles being hard on it. Towing a huge trailer gets down to 14 if hilly. Drive easy on it and it should be good. You 2wd guys should get better anyways.


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