Greetings Gentlepeople,

[afvman]

With a nickname like 'afvman' you can tell I have no life. I've been trying to make a living in the AFV business for 25 yrs now...and I'm still trying.

First with a coupla' of private conversion companies in the 80's then teaching at West Virginia University's National Alternative Fuels Training Consortium, for ten years but don't get me started on that!

I left WVU in 2002 and started AFV International LLC doing training, curriculum development, project management, codes and standards development and most recently working with CVEF and CSA America to develop the new CNG Cylinder Inspection Certification potocols.

I've finally figured out how to make a million dollars in alternative fuels...start with two million.

Best regards,

Bill

[John Mitton]

Re: Greetings Gentlepeople,

Hi Bill, and welcome to CNGchat!
Its good to have a veteran join up with us. We look forward to your wisdom

[afvman]

Re: Greetings Gentlepeople,

John,

Thanks, I'd be happy to help with any technical questions that you might have. My background is primarily in emissions and the early conversion technology

We also wrote the ASE CNG Technician F-1 exam and the Motor Age study guide for what that's worth. Iin academia it was publish or parish.

BTW, is Steve Ellis still with the alt. fuel program at Honda? Good people!

B/R,

Bill

[cngsteve]

Re: Greetings Gentlepeople,

Emissions, eh?

Bill, I currently have high NOx emissions (about double the allowed 700 ppm) from my 1994 Dodge Caravan dedicated CNG with 177K miles. These were manufactured with no EGR system, and I'm told that the EGR system helps control NOx. Here in the Los Angeles basin, they measure NOx at both 15 mph and 25 mph running the car on rollers. For reasons of state-required licensing, I have it with a (gasoline) smog specialist who will check out the usual suspects of sensors, cat, etc. I'm sure.

Where I'd be interested in your opinion is on the fuel injectors. I had to replace one about a year ago. I've since learned that this may lead to an imbalance across the cylinders, if any of the others have some clogging. Have you had experience with cleaning (ultrasonic, off-the-car) or replacing injectors on high-mile CNG vehicles like this, and it's effect on emissions? BTW, no coalescing filter on these vehicles either.

Thanks,
Steve

[afvman]

Re: Greetings Gentlepeople,

Hey Steve,

Coupla' of thoughts. High NOx can be created by either high temperature or high combustion pressures. In the case of CNG I wouldn't expect the carbon build-up in the heads that could result in higher compression ratios and NOx, so...

Higher temperature would be a better bet. Clogged (are partially clogged) injectors could result in leaner mixtures which could translate to higher combustion temperatures and NOx, so...

Anything you or your mechanic can do to reduce the head tgemperatures should help (i.e., cooling system flush, radiator fan configuration, etc.) Easy for me to say.

Second (and last) thought. Cleaning the injectors is always a good thing. I think the stuff about unbalanced injectors is bogus. Don't think that's your problem.

Good luck,

Bill

[cngsteve]

Re: Greetings Gentlepeople,

Thanks Bill.

[afvman]

Re: Greetings Gentlepeople,

Steve,

OK, three thoughts. It just occured to me that at 177k miles if you haven't already replaced the catalytic converter you probably should before you go thru the next inspection lane.

I'm an 'engine out' kinda' guy and don't put a lot of faith in chemical solutions normally, but that's what the cat is supposed to do...reduce NOx (among others).

So, that might be the easiest solution. Sorry I didn't think of it sooner.

B/R,

Bill

[scott]

Re: Greetings Gentlepeople,

Bill,

Yes, Steve Ellis is still with Honda. He is involved with the Honda Hydrogen Fuel Cell Clarity.