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I recently purchased by 7th first gen Insight and it's a bit unusual. I'm not complaining....the car goes into lean burn easier than any of the the others I've had and holds it there much longer. I can be using cruise and hit a slight incline and it still stays in lean burn. The result is the MPG is a dozen higher than any of my previous 5 speeds. It has the typical potenza's and runs the same as the rest....any idea why a car would hold lean burn so well?
 

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Maybe the problem was with the other six?

Sam
 

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I recently purchased by 7th first gen Insight and it's a bit unusual. I'm not complaining....the car goes into lean burn easier than any of the the others I've had and holds it there much longer. I can be using cruise and hit a slight incline and it still stays in lean burn. The result is the MPG is a dozen higher than any of my previous 5 speeds. It has the typical potenza's and runs the same as the rest....any idea why a car would hold lean burn so well?
Check threads by Jeff652 I believe he had a 505 ecu in one of his cars that got much better mileage. Check this thread out. http://www.insightcentral.net/forums/mpg-issues/21972-ecu-version-can-have-big-impact-mpgs.html
 

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My experience with lean burn:

In 5th gear, my car enters lean burn consistently when I let off the pedal until the FCD reads ~100mpg. From there, there's a brief pause and it jumps about 25mpg. Once in lean burn, it will stay there except for occasional NOx purges, indefinitely, unless I press the pedal far enough to drop the FCD below ~70mpg, which is around 2.5-3.5in of vacuum / 95% engine load, which equates to about ~30% throttle at my usual highway speeds.

It will not enter lean burn when the air outside is below ~40F. It will not enter lean burn until the coolant temperature is above... I guess maybe 160F? It will not enter lean burn within ~3 seconds of auto stop. It will not enter lean burn for ~6-10 seconds after using an injector kill switch. It will not enter lean burn above ~72mph, but will stay in lean burn if you accelerate to greater than this speed. It will leave lean burn below ~1000rpm in any gear.

I'd like to hear others' experience with lean burn, if the behavior is any different. I've driven a grand total of 2 Insights, both 2000 models, and both behaved the other behaved the same as mine.
 

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Finally, someone other than me that uses a vacuum reading for driving. Check and see what the TPS shows, I believe mine is usually aroung 24%. (23-30% for lean burn) Your figures are real close.

Learn to read the gauge and it will tell you a lot of what the engine is doing.
Timing and vacuum are my mandatory viewing.(especially with the turbo.)

HTH
Willie
 

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Sometimes my G1 needs a hard ride to get into lean burn more easily afterwards. I even have seen lean burn + assist recently.
 

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I've been convinced for a while now that the ease of LB is primarily related to the power output of the ICE. With various levels of valve sealing, ring sealing, cam wear, cam timing, etc. the engines probably vary a significant amount in output power. The weak ones don't LB as easily as the strong ones. JMHO of course.
 

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Probably ought to share this in a new thread, but

I recently replaced my EGR (again).
I first bought a used Acura V6 one that was compatible size/manifold wise.
It worked but not really much better than the worn out "stocker" I was replacing.

Researching egr valves I found the cardone valve (sold by Rock Auto and many other local stores as well), and upon investigating its manufacturing and improvements/features, decided it was the best bet for my $.

The issue in the excellent rebuild your old one video/instructions on IC issue with the contacts scratching/eroding the carbon contacts on the plastic contact board inside the Honda factory egr valve, is not going to be an issue with the cardone one, as its similar to the fix suggested in the repair video.

It simply has a friction contact /spring thats not an edge, but a simple curved area of the copper contacts in contact with the board. (That eleminates the scratching and subsequent rapid wearing away of the carbon on the factory's board, the usual failure mode of the factory egr valve.

I think this is a MUCH superior design as compared to the OEM egr, as it should last indefinitely, vs the OEM valve.

Interestingly, Initially, it didn't operate much different than the used Acura egr, (ie jerky, "fitfull" operation, definitely not optimal or best mpg delivering function.) IMHO. After about 150-200 miles a week or two, it slowly reaklly smoothed out its operation. It also, really improved the access and staying in lb with throttle changes (to a degree of course, but again much and noticably better than stock)!
 

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That's awesome. Are you noticing better mpg *while* in lean burn? And how much did the valve cost?

I'm testing a new car yesterday/today, and it seems to both stay in lean burn easier up inclines and get better mpg both in and out of lean burn. It's dramatic enough compared to the other 2 I've tested, I'm wondering if the mpg gauge is inaccurate.

It is a 2003 model vs 2000 and 2001 models, although my understanding is this should not make any difference.
 

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Absolutely better mpg, BUT

Its not "monstrous"..
If you read my other post re this, Its the transitions that are most affected (plus ability to stay in lburn a bit easier), that is the most noticable difference.
IE on a flat road once the lb was engaged, mpg's would be the same, I THINK.
With the egr smoothly adjusting, (the new egr valve), allows, when you are trying to get into lb, mashing and backing off the throttle is how I used to do it) thats wasting fuel, even more so than simply driving for max economy w/o lb.
3-5 mpg better, in town, mainly..BUT a much easier, less stressfull driving experience! IMHO
You arent constantly doing all or nothing egr decisions, but smoothly, in sync with the throttle, get appropriately sized amounts of egr.
(actually its inverse when working properly, more egr at small throttle openings = max mpg's)..
 

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Hmmm, OK. This Insight I'm playing with now is getting lean burn 60mph at nearly 100mpg! Total trip is over 80mpg! Return trip was a bit less, 73mpg.

I haven't figured out if there's tail wind or slight elevation change involved here. But this vehicle outperforms the other two I've tested noticeably. My friend confirmed the same, with the vehicle easily going in and out of lean burn without any intentional effort, kind of like how Honda meant it to operate I would think. His validation confirms the superior performance is not just my imagination.

Photo of 1st segment of trip at 80.6mpg:



At freeway exit stop light it was 82.9mpg! The 1.3 mile local lights, stop signs and parking dropped it to 80.6:

 

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some cars just work better than others, diagnosing the issues as you have seen in other threads can be nearly impossible to pinpoint the main problem as to why some cars work well and others don't. i've been working on cars for 25 years by trade and i still can't figure out why my highest mile insight won't lean burn efficiently.

i almost feel like just jumping on the turbo bandwagon and saying to hell with leanburn. my '01 just refuses to acknowledge that it can do anything more than coast to a stalling speed in lean burn.

i have a list a page long of things i have tested and tried, including swapping parts from the better running car.
 

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Lyger loss of part throttle low end tq?

That'd be my guess, if its dropped, but used to get better mpg's..

Also someone asked my mpg's in town I'm up to ocver 50mpg always (and I drive with traffic at a minimum. Its hot here now, and all in town 5 miles trip (each way) gave 54.3. a 35 mile (each way) work trip monday and tuesday netted 65 mpg at 60-65...
My opinion re in town better mpg, is hotter weather means tranny and engine oil is hot (er) sooner and at start, so thinner, and less drag... Then some cause these engines want warmer air for best mpgs (others have proven this, and my snorkel off the exhaust heat others posted about also works), just not in Summer!
 

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My CVT with the JDM ECM goes into lean burn effortlessly. At 60 MPH it tries to purge every 60 seconds, but a quick twitch of the throttle (either into the gas of off of the gas) kills the purge cycle. I am usually back into lean burn within one to 2 seconds of the purge starting.
 

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My CVT with the JDM ECM goes into lean burn effortlessly. At 60 MPH it tries to purge every 60 seconds, but a quick twitch of the throttle (either into the gas of off of the gas) kills the purge cycle. I am usually back into lean burn within one to 2 seconds of the purge starting.
i think plenty on here would be curious whether the Jspec ECM is a plug and play unit on the USDM cars. is it really that simple or did you have to modify things to get it to work? lean burn with a CVT, most would probably go nuts for.
 

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i almost feel like just jumping on the turbo bandwagon and saying to hell with leanburn. my '01 just refuses to acknowledge that it can do anything more than coast to a stalling speed in lean burn.

i have a list a page long of things i have tested and tried, including swapping parts from the better running car.
I know you have "worked this to death" very patiently and methodically. I've followed most of your work, since you clearly are a competent and thorough mechanic.

I have a theory - just a theory mind you. I think some of these older high mileage cars are down on ICE power. The reasons most likely vary. If you think about it, a low power ICE is going to impact LB. If the ICE can't deliver the power to maintain cruise speed, then LB will drop and the ICE will demand the richer fuel/air non LB mix.

It's a theory and I really can't fully defend it other than what I've said;)
 

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Lyger,
I have NOT seen your exhaustive list of things you've tried on your car, so excuse me if this has been covered before, but fuel injection spray pattern was a cause identified by Peter years ago to have made a big difference on one of his older cars.
This was also the one thing that I did not try to remedy on my first car which was low on power and did not leanbburn well.
As you know, there are services that refurbish them on a mail in basis.
 
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