The Diagnostic Guide to Alternative Fuels

I developed the Diagnostic Guide in web format starting in mid 1994.  From late 1995 through 2005, the webpage was been downloaded almost 18,000 times and viewed more than 130,000 times!  The material was obviously of some value because I found that the information was being sold online, and at least one prominent forklift service company had transcribed my material and was using it in their training programs! 

I initially provided this material at no charge but I realized that it was time to be compensated for my work.

I reformatted the material into booklet format and have offered it in a PDF format booklet.

About the author:

I have spent almost 50 years experience in the automobile service industry and almost 30 years with Alternative Fuel vehicles.  I have held ASE Master certifications, including Advanced Drivability, and Alternative Fuels, and currently possess many other licenses and certifications.  I am recognized as a trainer, diagnostician, and installer by most of the alternative fuel equipment manufacturers located in the United States and other parts of the world.

Volume One Covers:

Volume one exclusively pertains to LPG/Propane powered vehicles with mechanical carburetion components, and with electronic fuel mixture controls. 

There are no plans to incorporate any of the material for CNG/Compressed Natural Gas vehicles.

In this manual, you will find resources related to:

  • What is propane, where does it come from, how is it made and stored;

  •  Propane basics, how it behaves under pressures and temperatures;

  • Comparing propane to gasoline;

Diagnosing a propane vehicle that:

  • Will not start

  • Idle, various conditions

  • Power-up

  • Hesitations

  • Lack of power

  • Backfire problems

  • Malfunction indicator lights (MIL's, or the Check Engine Light)

  • Surging on acceleration or cruise

  • Dying on deceleration

  • Emissions tuning, how to set up commonly used closed loop electronic engine controls

Tips and hints on:

  • Setting up the Impco 100, 125, 200, 225, 300, 425

  • The OHG X-450 (and later variants)

  • Engine building recommendations, including camshafts, cylinder heads, pistons and compression ratios, ignition systems

  • Common engine failures, what caused them, how to prevent it from happening again

  • What causes the sludge frequently found in propane components

Volume Two:

Volume 2 was initially intended to supplement the Diagnostic Guide, but, I was contracted by the Propane Council to develop a series of training manuals whose intent was to distribute them at no charge.  The Propane Council posted the books online for approximately 3 years at which time, they withdrew them from access.  The Propane Council has since offered training classes provided by West Virginia University using their internally developed curriculae.

I am in the process of attempting to obtain permission to release the booklets through this site, and at which time I will offer them to my viewers.


How to Buy:


The purchase price for ONE copy of this book is USD $16.95 using PayPal.  PayPal USUALLY adjusts the fee to reflect foreign transactions.

Send me an email via the contact page and I will send you the purchase information.

This book is only available in PDF format and will be emailed.


The information is provided "as is" without any warranty, condition, or representation of any kind, either expressed or implied, including but not limited to, any warranty respecting non-infringement, and the implied warranties of conditions of merchantability and fitness for a particular purpose. In no event shall Franz Hofmann, or any directors,trustees, associates, or employees thereof be liable for any direct, indirect, special, incidental, consequential or other damages howsoevercaused whether arising in contract, tort, or otherwise, arising out of or in connection with the use or performance of the information contained on this web site. 

By accessing this website, you agree by these conditions.  This is a 'Litigation Free' website.
ALL information on this website inclusive is protected under the US Digital Millennium Copyright Act of 1998.  Click HERE for information.  This website is NOT public domain material.

Located in Central Texas

Web-page developed by Franz Hofmann
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