VX California to 49state Conversion help

[MetroMPG]

oldertech: congrats on the early success. I'd highly recommend getting an MPGuino to fine tune your technique. The instant MPG screen is as good a lean burn indicator as anything!

turbothrush - thanks for posting that info. (Where are you in Canada? I looked for a VX briefly before settling on the Metro/Firefly - the few VX's I saw were either Swiss cheese with rust or stupidly expensive.)

[oldertech]

Today i ran into a new trait that I'm not happy about. The California setup was rock solid with it's driving habits. Never missed or stumbled at all. We now have a VERY occasional stumble at low rpms with the Fed setup, like today just after a shift with light throttle from first to second. Might be the only one that happens in a day of driving. Little "miss" of some sort. Is this setup just more sensitive and perhaps the higher-mileage engine makes it burp more easily?

Scott

[MetroMPG]

If I'm not mistaken, that's the "lean burn stumble". If you have an MPGuino or a lean burn indicator, you'll see the correlation.

Learn to love it - that's why you're getting the good MPG now.

I've only spent limited time in a lean burn Honda (Ben's VX engined CRX), so I found it a bit hard to notice. But Ben could identify the hiccup and knew when he was in lean land without needing to confirm on the fuel economy display.

[Christ]

Aye, according to every Honda Technician I know, they all hated the lean burn setup for only one reason - it's not very "smooth" in transition... the Honda ECU doesn't slowly lower the AFR, it literally just drops the fuel ratio under the curve when the input is correct to enter lean mode.

So you might be cruising along, and lift your foot off the pedal slightly, and all of a sudden, you're in lean mode, and you feel a 'burp' in the otherwise smooth operation of your engine... what's actually happened is that while you were cruising along, you were probably maintaining an AFR close to 14-15:1... all of a sudden, the stars aligned with the moon, Saturn entered it's third phase, and Jupiter got rings, and your AFR dropped down to something closer to 17-20:1 (if I remember correctly).

So what actually happened? Ever get an air bubble in the carb bowl while tuning a carb'd car? When that happens, you get a 'burp' from the engine... one or two cylinders don't fire for a cycle. Bam - there's your explanation.

If you're absolutely bothered by it, you could try a few things, like softer motor mounts, or making sure that all of yours are perfect and that your engine is aligned correctly (there is some play in the mounts of most Hondas, which allows you to re-align the engine slightly.)

The softer your mounts are, the less feedback you get from the engine when it makes funny and does things you don't think it should be doing.

[oldertech]

Christ, you are a funny writer. I was at the gym when I read your post and laughed out loud about the planets aligning for the sake of a Honda VX.

I read that the EGR valve can contribute to a stumble so I took it off and cleaned it up, new gasket and off I drove tonight without any stumbles. I wouldn't change any engine mounts but I hear what you are saying. All along, when I have been researching the VX and wondering about it's operation in LeanBurn, I've figured that was some kind of tradeoff for the mileage, and apparently there is. Good to know that Honda mechanics hate it. So I'll keep my head under the hood and won't bother them with such an efficient machine subject to untimely burps.

I know the valves are a bit noisy. Would I benefit any MPG by adjusting them?

I was hypermiling back in the 80s with my MGB and a CalCustom MPG computer and I'm doing it with my Chevy Cobalt with mpg indicator. Those cars trained me what to do to get good mileage, but I do need to seriously look into this MPGuino gizmo.

The VX is such a perfect car for me to be driving. I've always liked older technology that performs in advanced ways to achieve things that other products, cars, etc., aren't doing. Often that means some exotic technology that was prone to "burps." But I like that once I understand them. Look at my website Oldertech.com Two of my other cars are old British cars with liquid suspension and front wheel drive. Wonder how they'd run with a VX Honda motor under their hoods????

Thanks for the posts and advise from MetroMPG on the "lean burn stumble." Just drove the car around town and to Kansas City and back, racked up 150 miles and the fuel gauge is just south of F. Oh happy day. I think the truckers hate me for staying in Leanburn on hills.

Scott

[TomO]

Congrats on the good news. Glad to hear about another VX owner actually enjoying the LeanBurn bump.

I can notice the bump in my VX but ever since I put the NGK Power Cables in, it seems to be even less noticeable. They are spendy plug wires but they help reduce any lean burn misfires.

[oldertech]

We bought the Honda dealer plug wires, which were indeed pricey, so we don't have aftermarket there. The ones you have are even better?

Scott

[TomO]

Originally Posted by oldertech

We bought the Honda dealer plug wires, which were indeed pricey, so we don't have aftermarket there. The ones you have are even better?

Scott

The NGK Power Cable have far less resistance than the OEM ones. The OEM ones are great quality but are around 1.5K - 1.7K Ohms per wire. the NGK Power Cables are about 300 - 470 Ohms per wire as measured on a few sets I've had my hands on. The less resistance allows for a hotter temp spark which works well for lean burn conditions. And the way that NGK winds the wire it has no noticeable EM Interference. But the Power Cables are $80 the cheapest that I can get them for.

[oldertech]

Dang. The dealer wires were about that price.

Scott

[oldertech]

I agree with you all, it would be nice to add the mpg meter, but in the meanwhile, I just want to monitor the leanburn with a light.

Today I put a voltage meter on the wire leading to the vtec valve. In my mind, it would seem that there would be a change of state on that wire when it is told to alter the cam and open or shut the valves. I measure .02volts on the wire when the car is on and 0 when its off. When Leanburn is kicking in and out I see no change in voltage. What am I missing on this?


TomO, your signature has civicvx.com as a link, but it's a dead link. Did you used to have a page on the VX?

Scott