---------------------------------------------------------- RV4-List Digest Archive --- Total Messages Posted Wed 10/22/03: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:21 AM - Re: Re: RV4-List Digest: 1 Msgs - 10/19/03 (rob ray) 2. 07:30 AM - Re: Re: RV4-List Digest: 1 Msgs - 10/19/03 (Steve Mullins) 3. 08:13 AM - Re: Re: RV4-List Digest: 1 Msgs - 10/19/03 (rob ray) ________________________________ Message 1 _____________________________________ Time: 06:21:41 AM PST US From: rob ray Subject: Re: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 --> RV4-List message posted by: rob ray Ross, next time the you try it (at a safe altitude) turn on the boost pump and see what the pressure does. I agree that it could be a vent or line problem as well. One easy way to tell would be to switch tanks, 100LL in the suspect, MoGas in the other...I am well past 1000 hours of MoGas use with not one complaint except the smell... RR Ross Scroggs wrote: --> RV4-List message posted by: "Ross Scroggs" Steve, Is it possible that the tank with the auto fuel has it's fuel tank vent partially plugged? That could be the reason for the drop in fuel pressure. In flight, while running on auto fuel, watch for any change in the appearance of the tank skins compared to the tank with 100LL. The auto fuel tank may be getting sucked in which may be visible. Do you have sloshing compound in your tanks? If so, it could be releasing and plugging up the tank pickup. Good luck, Ross Scroggs RV-4-#3911 Wings ----- Original Message ----- From: "Steve Mullins" Subject: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 > --> RV4-List message posted by: "Steve Mullins" > > Hello all, > > I am in desperate need of advice. I have been running auto fuel in my 0-290 > powered 4 for three years with no problems until recently. Fuel pressure > starts to fluctuate and drop once temps come up. I switch back to avgas tank > and things return to normal. Is this likely vapor lock? Are there other auto > gas issues I need to be aware of? Prior to this recent development, the > engine runs just as good with either fuel. > > --------------------------------- ________________________________ Message 2 _____________________________________ Time: 07:30:34 AM PST US From: "Steve Mullins" Subject: RE: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 --> RV4-List message posted by: "Steve Mullins" I have tried the boost pump, and it brings the pressure back up, but it still fluctuates much more than when on the avgas tank. So does this tell me it is vaporlock? I am leaning toward the vapor lock explanation cause it has been unusually warm here, and I have been told that the gas companies switched to their 'winter blend' at the beginning of October. Wahtcha think? -----Original Message----- From: owner-rv4-list-server@matronics.com [mailto:owner-rv4-list-server@matronics.com] On Behalf Of rob ray Subject: Re: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 --> RV4-List message posted by: rob ray Ross, next time the you try it (at a safe altitude) turn on the boost pump and see what the pressure does. I agree that it could be a vent or line problem as well. One easy way to tell would be to switch tanks, 100LL in the suspect, MoGas in the other...I am well past 1000 hours of MoGas use with not one complaint except the smell... RR Ross Scroggs wrote: --> RV4-List message posted by: "Ross Scroggs" Steve, Is it possible that the tank with the auto fuel has it's fuel tank vent partially plugged? That could be the reason for the drop in fuel pressure. In flight, while running on auto fuel, watch for any change in the appearance of the tank skins compared to the tank with 100LL. The auto fuel tank may be getting sucked in which may be visible. Do you have sloshing compound in your tanks? If so, it could be releasing and plugging up the tank pickup. Good luck, Ross Scroggs RV-4-#3911 Wings ----- Original Message ----- From: "Steve Mullins" Subject: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 > --> RV4-List message posted by: "Steve Mullins" > > Hello all, > > I am in desperate need of advice. I have been running auto fuel in my 0-290 > powered 4 for three years with no problems until recently. Fuel pressure > starts to fluctuate and drop once temps come up. I switch back to avgas tank > and things return to normal. Is this likely vapor lock? Are there other auto > gas issues I need to be aware of? Prior to this recent development, the > engine runs just as good with either fuel. > > --------------------------------- ________________________________ Message 3 _____________________________________ Time: 08:13:30 AM PST US From: rob ray Subject: RE: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 --> RV4-List message posted by: rob ray Probably a good call on vaporlock. Try mixing the MoGas 50/50 with 100LL and see what happens. If the problem disappears, it was a strong possibility it was Vapor lock. I run a 75/25 (auto/av) mix now with good results. I asked my Amoco station guy here in AL and he said they don't go to a winter blend until January-Feb. RR Steve Mullins wrote: --> RV4-List message posted by: "Steve Mullins" I have tried the boost pump, and it brings the pressure back up, but it still fluctuates much more than when on the avgas tank. So does this tell me it is vaporlock? I am leaning toward the vapor lock explanation cause it has been unusually warm here, and I have been told that the gas companies switched to their 'winter blend' at the beginning of October. Wahtcha think? -----Original Message----- From: owner-rv4-list-server@matronics.com [mailto:owner-rv4-list-server@matronics.com] On Behalf Of rob ray Subject: Re: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 --> RV4-List message posted by: rob ray Ross, next time the you try it (at a safe altitude) turn on the boost pump and see what the pressure does. I agree that it could be a vent or line problem as well. One easy way to tell would be to switch tanks, 100LL in the suspect, MoGas in the other...I am well past 1000 hours of MoGas use with not one complaint except the smell... RR Ross Scroggs wrote: --> RV4-List message posted by: "Ross Scroggs" Steve, Is it possible that the tank with the auto fuel has it's fuel tank vent partially plugged? That could be the reason for the drop in fuel pressure. In flight, while running on auto fuel, watch for any change in the appearance of the tank skins compared to the tank with 100LL. The auto fuel tank may be getting sucked in which may be visible. Do you have sloshing compound in your tanks? If so, it could be releasing and plugging up the tank pickup. Good luck, Ross Scroggs RV-4-#3911 Wings ----- Original Message ----- From: "Steve Mullins" Subject: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03 > --> RV4-List message posted by: "Steve Mullins" > > Hello all, > > I am in desperate need of advice. I have been running auto fuel in my 0-290 > powered 4 for three years with no problems until recently. Fuel pressure > starts to fluctuate and drop once temps come up. I switch back to avgas tank > and things return to normal. Is this likely vapor lock? Are there other auto > gas issues I need to be aware of? Prior to this recent development, the > engine runs just as good with either fuel. > > --------------------------------- ---------------------------------