The Impsight: My mischievous little devil of a car. ('00 Insight fixing and modifying)

[S Keith]

Originally Posted by Stubby79

Showing the battery my opinion of it after tearing apart the interior and fighting a seized bolt:



(Mod, feel free to delete it if it's too spicy for this forum)

I was expecting orange sticks:



Those are distinctly yellow. They've been replaced at some point.

I haven't read the entire thread in detail - an aggressive skimming at best.

Your reaction to the IMA battery is 1000% appropriate. They are likely Civic sticks. While superior, they are not optimal unless the BCM is reprogrammed, which isn't an option on all years.

You can probe the gray/orange plug (orange cable from the battery) and measure the voltages of stick pairs:

https://www.insightcentral.net/threa.../#post-1006193

They should be nearly identical.

You can get detailed DTC by "blinking" the codes:

Reading the blink codes - MIMA Honda Insight Modified Integrated Motor Assist

You count the flashes of both the IMA and CEL and look up the appropriate two digit code.

insightcentral.net has many useful resources.

[MetroMPG]

Worth checking those passages. Though you would have known from driveability issues if they were bad.



The Insight has a cabin filter!? I never knew - never checked mine!

[Stubby79]

Yeah, I have(had?) a bit of a driveability issue...in lean burn, under higher load, the engine felt rough or like it was missing. Not an issue at lighter loads in lean burn. And it would tend to give a decent jerk/miss if you punched the gas to get it out of lean burn.

So I jumped to the conclusion that it was the EGR passeges, but they were fine.

Then it came down to fuel - I assume what was in there is really old - or spark plugs. I had put what little fresh gas would fit in it as soon as I got it, and after checking the EGR I then went and filled it back up - a whopping quarter of a tank - with high octane. It seemed better, but not completely gone. Still could be fuel. Will take me forever to burn through the whole tank though...

So...spark plugs were next. Which I just finished screwing around with. They were a bit past maximum gap spec, so I regapped them. Of course, they weren't indexed. So I spent a couple of hours trying to index them...without proper indexing shims. Copper wire and extra crush washers from old spark plugs...

Don't waste your time trying to do it without proper shims...a second crush washer seemed to put it right back where it was with only one on there. I did, through much trial and error, get them close. First one only needed a bit of extra torque to get there (be careful, I gave myself a limit by setting my torque wrench, and got it lined up before hitting that limit) but the other two? Yeesh.

One was pointed straight back between the exhaust valves, the other was pointed past the "vtec" valve. They're supposed to point towards the non-vtec valve, apparently. They're both a bit past that now, and one is shimmed enough that I am concerned it will mess up the heat range, but...at least they're nowhere near out of whack as they were.

I drew a line on the end of the spark plug cap with a white grease pencil (pointing towards the open side of the electrode) to tell which way they were pointing, if that's any help to anyone else doing it.

Besides that...if I didn't say it already, I had adjusted the clips/slots that hold the rear wheel skirts on last weekend. I noticed as I was about to leave for work Saturday that one corner of the driver's skirt was not secured at the bottom...oh look, both retaining "screws" were missing. Pulled the skirt off before I lost it...Either I had not tightened them properly, or they were still sitting in my magnetic bolt tray.

They were in my bolt tray. Good thing I had tightened those clips down as well as I had, or it would have been lost days ago. I drove all week with it like that, until the last work day, anyway.

They needed adjusting in the first place cuz the skirts did not sit flush with the body. Both stuck out at different points around the perimeter. They're nice and flush now.

Brake rotors showed up while I was screwing around with the spark plugs. Guess I know what I'm doing tomorrow morning...

[MetroMPG]

I'm embarassed to say I never even pulled the plugs on my Insight. It ran fine after the EGR cleaning and got well over 100 MPG US (aeromodded) in my typical use, so I figured they were OK.

I do remember sometimes the lean burn transition (coming out of it) could give a bit of a bit jerk though. (I also remember the pedal responsiveness got decidedly "mushy" when you go into L.B.)

Thinking about that car - it's amazing to me that Honda let the engineers get away with all the things they did in pursuit of uber-efficiency considering the potential impact on "consumer acceptability".

Makes you wonder what features / details / design elements were shot down by the decision-makers and didn't make it into production!

[Ecky]

I believe the "lurch" coming out of lean burn is normal.

If you can't resolve the jerky behavior with plugs or EGR, there's a fair chance it's from timing chain slop.

[MetroMPG]

Don't forget the EGR valve!

[Gasoline Fumes]

Originally Posted by Ecky

I believe the "lurch" coming out of lean burn is normal.

If you can't resolve the jerky behavior with plugs or EGR, there's a fair chance it's from timing chain slop.

Timing chain? I hadn't heard that as a possible cause yet! I tried just about everything else.

[Stubby79]

We'll find out after I've done the brakes and take it for a drive...if all is well, the shims stay...if it's the same, I'll get around to it later...if it's worse, they come out ASAP.

Timing chain? Doesn't fit with my concept of the circumstances. Might explain the miss under load while in lean burn, though I'd expect such issues all the time under load. If I took my foot off the gas then punched it, I might expect it to behave that way, but the engine was already under load - throttle open, say, 20%, when I punch it. There's no engine going slack(going from pushing to being pulled then back to pushing again suddenly) to cause any slack in the chain to mess up valve timing momentarily.

My...assumption...is that there's no way for the fuel delivery to respond immediately when you punch it. There's a sudden flooding of air in to the intake, the injectors are only firing enough to do lean-burn A/F ratio, so now, for that one brief moment, the A/F ratio goes extremely lean, and can't ignite it...or there's enough air in the cylinder (and not enough fuel to cool it down) to cause the compression to ignite the fuel prematurely. Either way, you get a misfire, just for that one cylinder that's firing during that one brief moment it takes the engine/ecu to compensate and start flooding in fuel to match the amount of air going in.

It's just a logical guess. If the engine goes stupidly lean for a moment, it would certainly make the engine hiccup like that.

It's probably not an issue with a normal - non lean-burn - engine, as there would be enough fuel to fire anyway. Lean, sure, but not enough to cause anything noticeable. Plus the ECU might simply take a moment to switch fuel maps, which a non-lean burn wouldn't have to.

AND...just to add more fuel to the fire...the programming of the Insight's ECU is presumably set to maximize fuel economy...it ignores the TPS telling it that the throttle has been opened suddenly, until the MAP sensor confirms the sudden change in manifold vacuum/pressure...by then, the air is already flooding in to one of the cylinders, and it's too late to fire the injector for longer.

Anyway, if it's pre-ignition, from too much compression/too lean, in theory, higher octane fuel could fix this. Anything fresh is probably higher octane than the ancient gas that was potentially in it, but high octane would help even more. I didn't get to drive it enough to decide one way or the other before I messed around with the spark plugs yesterday. It seemed to be smoother - not perfect, but better - with the fresh, high-octane mixed in, so I didn't get annoyed enough to punch it trying to get it out of lean-burn.

I could see it misfiring in lean-burn due to too much spark plug gap at the larger A/F ratio in lean burn, made worse combined with heavy load. So the spark plug gap had to be checked. If the indexing of spark plugs affects air flow/ignition of the fuel, that could be just as important.

From what I understand, Honda used to safely/successfully ignite their lean A/F mixture by sending in a second, richer (stoich, presumably) air/fuel charge that was easier to ignite, and in turn could ignite the rest of the leaner charge in the cylinder...if you assume they use a similar technique in the insight, using the sequential injection to dump in a richer charge right before the valve closes, then indexed spark plugs could be absolutely necessary to ensure that the richer charge is ignited properly. (If it's homogeneous - yeah right - it probably wouldn't matter nearly as much)

More theories/educated guesses. Whatever. What we do know is that misfires are caused by (bad) a/f ratio, heat build up (compression/hot spots on valves), and/or not being able to fire the spark plug. I'd lean towards one of these causing the issue, regardless of the why of it. (Though good luck fixing it without knowing the why of it!)

[Ecky]

I think we can rule out pre-ignition. Lean ratios past stoich generally don't cause this, because combustion temperature starts to drop again above ~15.3:1 (E0).

Maybe try running non-ethanol gas for one tank? Stoich AFR is slightly different.

[Stubby79]

If not pre-ignition, then why the stuttering under load in lean burn? Why seem less with better gas in it? Unless that was entirely in my head.

On the other hand, if it was firing the spark plugs a bit too early, due to the cam chain, I suppose that might cause it.

Hows about the non-indexed spark plugs? If that caused some of the mixture to burn, but not all, the rest of it might get ignited by the build up of pressure and suddenly what's left self-ignites right before TDC and causes a jerk, like, presumably the timing being too far advanced.

Of course, I haven't heard any pinging in the exhaust. Maybe you won't with engines that don't open the exhaust valve until BDC. Didn't notice it on my Metro with the XFI cam, no matter how low of an RPM you got when upshifting.

*scratches head* Now I'm just confusing myself, or at least feel like I'm missing something. We'll see what happens as I check off each variable until it goes away. With the fuel, that might take a month or two before I can fill it with all fresh...