Problematic OEM Dual Fuel Systems
Thread Starter
|
Member
Joined: Apr 2006
Posts: 18
Likes: 0
Problematic OEM Dual Fuel Systems
Having read fairlaner’s postings on Propane Conversion, I tried to find out more about the problem he was having:
I asked about these propane systems on my propane forum and found out that these systems were supplied by Teleflex GFI. I’m not sure why Ford decided to go with their system but I’m sure it worked perfectly before they signed the contract. Once in the field, however, the vaporizer and the “Compuvalve” were often failure-prone as described by fairlaner. However, the repair prices he reports seem to be out-of-line and his company is probably being gouged a bit by the repair shop.
Apparently there are other companies in the process of developing repair parts for the defective GFI items but none are commercially available yet. I checked with Technocarb and they don’t have a repair kit either. However, they told me that it would probably cost less to remove the entire GFI system and replace it with one of their injection systems for less than the cost of that particular shop’s compuvalve repair. However, since fairlaner is in California, a repair like that would probably be in a gray area with regard to CARB certification.
With regard for the need to shut the engine off to switch back and forth between fuels, this was a safety feature specified by Ford. Often, people would switch to propane operation while climbing hills to compare propane performance with gasoline. The problem with that is that there is potential for the fuel mixture to become extremely lean in the process to result in a lean backfire. Fuel injection manifolds were never designed to convey fuel mixtures and are particularly vulnerable to fuel transport delay lean backfires. To eliminate the potential for such warranty claims, Ford specified that their systems can only be switched to propane when the engine has been shut down.
Has anyone else experienced a similar problem? How did you resolve it?
Originally Posted by fairlaner - post #15
At work, we have 40-50 factory equipped f-150 bi-fuel trucks (propane/gas). They are 2001-2003 7700 5.4 auto. We have found the trucks to be very troublesome. In the 100k miles total I have put on two trucks, I ran three tanks of propane, because I was afraid the truck would breakdown and would end up at the dealer for a long period of time. Our mechanics hate the system and tell me unofficially they are trying to get enough of the systems to fail to justify taking them off the trucks. Other than the bi-fuel, I love driving these 7700's.
Originally Posted by fairlaner - post #17
To run the truck on propane, you have to shut off the motor, switch to propane and then restart the motor. What would happen is you would shut off the truck, switch to propane, and the truck would not start. You would then switch back to gas and the truck still would not start. At this point, your truck was put on a lowbed and hauled to a dealer in Sacramento. You might see your truck again in a month! Our mechanics told me a valve under the hood was often the culprit, to the tune of over $2500! These valves would also leak propane under the hood...not a good situation. In all fairness to Ford, the little bit I ran the propane system the truck ran great, although you had to crank the motor approx. 3 times as long to start!
Apparently there are other companies in the process of developing repair parts for the defective GFI items but none are commercially available yet. I checked with Technocarb and they don’t have a repair kit either. However, they told me that it would probably cost less to remove the entire GFI system and replace it with one of their injection systems for less than the cost of that particular shop’s compuvalve repair. However, since fairlaner is in California, a repair like that would probably be in a gray area with regard to CARB certification.
With regard for the need to shut the engine off to switch back and forth between fuels, this was a safety feature specified by Ford. Often, people would switch to propane operation while climbing hills to compare propane performance with gasoline. The problem with that is that there is potential for the fuel mixture to become extremely lean in the process to result in a lean backfire. Fuel injection manifolds were never designed to convey fuel mixtures and are particularly vulnerable to fuel transport delay lean backfires. To eliminate the potential for such warranty claims, Ford specified that their systems can only be switched to propane when the engine has been shut down.
Has anyone else experienced a similar problem? How did you resolve it?
Last edited by fraso; Jan 14, 2017 at 12:06 PM. Reason: link updaet