About Us

Company History

In 1951, when Frank Ostoich envisioned Diesel Injection Service, he was working as a mechanic at the Colton Cement Plant. Previously (both before and after his service to his country in World War II), Frank drove trucks for a variety of concerns, including Colton Cement Plant. During World War II, Frank served his country as a Chief Machinist’s Mate on a sub chaser in the Mediterranean. It was during World War II that Frank honed his skills. In 1951, Frank rented a corner of an established truck repair shop located at 932 West Mill Street, known as Commercial Auto Repair, which was owned by “Slim” Doubenmeier, a well-known, local truck mechanic. Slim’s dedication and ingenuity made a lasting impression on Frank. Diesel Injection Service was now in business!

While Diesel Injection Service began as a part-time venture, it quickly grew into a full-time occupation for Frank.  The customer was always foremost in Frank’s mind, as he made every effort to “fill the need” of the trucking public.  The business quickly grew and, during the 1950s, Frank hired Bill Grammer and Jack Frost, who both remained in the business with him for decades.  Frank, Bill and Jack set the standard for excellence that has positively affected each and every subsequent employee.

Frank actively worked in the business until December 2006 (age 91).  To the end, his life was dedicated to serving the public.  Although he is no longer physically present in the business, the standards of excellence he set over the decades continue to guide the current generation at Diesel Injection Service.  Some of the current employees of Diesel Injection Service have themselves been there for decades, carrying on the tradition of stability and excellence.  Frank believed that people are the key to success in every business.  He was right!

In 2012, Diesel Injection moved from its long-time location at 932 West Mill Street (after 61 years) and relocated to larger quarters at 1620 Fairway Dr. Colton, California.

Mission Statement

To provide our customers the highest level of quality in products and services at a fair price, while also upholding our guiding principles to recognize that profitability is essential to our success and continued growth.  To be admired by our customers and peers for our people, our performance and our passion for the diesel industry.

Guiding Principles 


Integrity – To conduct ourselves and our business with the highest integrity to our customers, governing authorities, vendors, employees and our industry peers.

Quality – To continually strive to exceed our customers’ expectations for quality in customer service, quality of service, and quality of products.

Responsibility - To continually strive to meet the responsibility we have with our community, our future, and our employees.

Knowledge – To continually strive to gain knowledge in all aspects of our business to serve our customers’ needs and be the industry leader in future technologies.

Loyalty – To continuously gain the respect and loyalty from our customers, vendors, and employees