Home » Public Forums » GMCnet » VAPOR LOCK and FUEL BOILING. (Trip Report)
VAPOR LOCK and FUEL BOILING. [message #139825] |
Thu, 18 August 2011 13:58 |
djeffers
Messages: 219 Registered: June 2004
Karma: 2
|
Senior Member |
|
|
Hello all,
Late last saturday afternoon, 13 Aug 11, we left Dunnellon, FL in north central Florida, for Shipshewana, IN in very northern Indiana, going north on I-75.
We made it to Valdosta, GA and overnighted. We found some very low priced gas, filled up and spent the night at Walmart.
Got on the road around 10:30 a.m. the next morning. It was a pretty hot day. After driving for a while, the coach began to stumble and shortly thereafter began to backfire and the engine quit.
Coasted over to the shoulder on I-75. The engine would not restart, just cranked and backfired. About 20 or 30 minutes later the coach started right up and we resumed our drive north.
I pulled into another gas station and topped off the fuel. When I took the gas cap off I could HEAR the fuel bubbling and boiling. The coach took only about 10 gallons of fuel. The fuel filler sounded similar to what it does when filling the tanks and the fuel is nearly full and it takes a while for the fuel to drain down.
Got back on the road and about 20 miles later the same thing; stumble, backfire, quit and coast over to the side of the road. Not safe!
Got on the road again 30 minutes later and we changed the fuel filters at a rest stop. Back on the road and sure enough, 20 or so miles down the road the same thing. We made it off the Interstate and coasted onto an uphill off ramp at the Johnstonville Road exit, still in south GA.
I thought maybe we had a second fuel pick-up sock obstructed, as we already have one sock obstructed that we have blown out once. The wiser mind, Susan, was not so sure and observed that the problem seemed temperature related.
I walked up the hill on the off ramp and found a peanut stand next to a fairly large paved parking area across from the only other structure around, a Marathon gas station. Asked the the individuals working the stand (Peanut and David) if I could pull the coach into their lot.
Peanut and David, father and son southern gentlemen that they are, said yes and that they would help us any way they could. They told us to pull up on a slab on the lot and we could put our awning out, relax and work on our coach all we needed to. Peanut and David were a Godsend.
While I was working on the coach Susan checked the Black List and found a GMCer just 16 miles north, Chuck Chambers.
I called Chuck and expressed my need (I thought) to drop the fuel tanks and replace the socks and fuel lines with new. I thought too maybe the alcohol in the newer fuels had taken its toll on the older rubber.
Chuck told me that 20 or 25 GMCers at a recent Georgia meet had experienced the very same symptoms and that it was VAPOR LOCK caused by the new fuels.
I was a little reluctant to believe that diagnosis as we have been in the desert heat at high altitudes with the coach and never had a problem. We also have an electric fuel pump to help overcome vapor lock conditions.
Chuck advised that we wait until the roads cooled down before continuing on. It was already about 7:30 p.m. or so and it had been a long hot day.
Wiser heads prevailed, (Chuck's and Susan's). So Susan and I drove the toad a couple of exits down to a Waffle House and had a meal. By then it was after dark.
We left the Johnstonville Road exit about 9:30 p.m. and took off running hard and fast to check the vapor lock hypothesis. Sure enough the coach ran great in the cool of the evening.
I ran as much of the bargain gas out as I could and refueled with name brand gas, hoping that might help any vapor pressure problem. We drove straight through the night at 60 to 65 mph to Knoxville, TN and overnighted again.
Chuck was apparently correct; it was a combination of the newer fuels and the hot day and roadway that caused the problem.
It seems the fuel we had bought may have had a lower vapor pressure boiling point making the coach fuel tanks susceptible to the radiated heat from the hot roadway. We did not have the problem the afternoon before in hot Florida.
The next day in north Tennessee was about 20 degrees cooler than when we were on the road in south Georgia. We continued on without problem to Shipshewana and National RV Refrigeration, arriving in the late evening. We slept in the coach.
The next morning Leon Herschberger of National RV Refrigeration arrived and we left the coach with him to rebuild our Dometic 3 way refrigerator.
Many thanks to Chuck Chambers, Peanut and David as well as Roger Black for all their help.
The GMC adventure continues!
Don & Susan Jeffers
78 Eleganza II
|
|
|
|
|
Re: [GMCnet] VAPOR LOCK and FUEL BOILING. [message #139831 is a reply to message #139829] |
Thu, 18 August 2011 14:41 |
jknezek
Messages: 1057 Registered: December 2007
Karma: 5
|
Senior Member |
|
|
Mr ERFisher wrote on Thu, 18 August 2011 15:23 | > That's distressing. What ever happened to the winter blend / summer blend for gasoline? It's enough to make me consider a bottle of snake-oil.
or an electric fuel pump
gene
|
I'm not sure an electric fuel pump is much of a solution to this type of problem. I've seen too many people come on the board, including this thread, and said they had vapor lock while using an electric fuel pump. I've had our coach in South FL and Alabama since I bought it, run it on the hottest of summer days, and the only time I had vapor lock was when the exhaust came loose under the coach and I ran up a mountain while towing. That's with a stock mechanical pump.
It seems to me we have very little actual consensus, just anecdotal evidence, to suggest solutions to vapor lock. Personally, with the incredibly random occurences that get mentioned on this board, I believe the problem is in the varying qualities of gas you get while on the road.
Unfortunately that doesn't lend itself to any kind of simple solution. I know at various times we've discussed electric pumps, in-tank pumps, insulating the tanks and lines, insulating the line across the carb, running the lines through a cooler, heat shielding the bottom of the coach, etc. But I haven't heard of anything that actually works for everyone. Not to say that some ideas don't help, just that nothing seems to solve the problem completely.
Thanks,
Jeremy Knezek
1976 Glenbrook
Birmingham, AL
|
|
|
Re: [GMCnet] VAPOR LOCK and FUEL BOILING. [message #139834 is a reply to message #139825] |
Thu, 18 August 2011 14:49 |
Ken Henderson
Messages: 8726 Registered: March 2004 Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Don,
I can't believe you didn't make the short detour by here! We'd have had
those tanks out before the fuel could quit boiling! :-)
Glad you found Chuck and his wiser head prevailed.
I'm glad you mentioned the refrigerator. I've got a perfectly good Dometic
2652 sitting under the RV shelter that they refused to repair under the
recall -- because it was no longer a fire hazard after all the ammonia
leaked out. :-( I should take that to Goshen and have Leon rebuild it for a
spare -- or sale. Have to try to figure out a way to carry it.
Ken H.
On Thu, Aug 18, 2011 at 2:58 PM, Don Jeffers <don.jeffers@frontier.com>wrote:
> ...
Got on the road around 10:30 a.m. the next morning. It was a pretty hot
> day. After driving for a while, the coach began to stumble and shortly
> thereafter began to backfire and the engine quit.
> ...
> Chuck told me that 20 or 25 GMCers at a recent Georgia meet had experienced
> the very same symptoms and that it was VAPOR LOCK caused by the new fuels.
> ...
> Chuck was apparently correct; it was a combination of the newer fuels and
> the hot day and roadway that caused the problem.
> ...
> The next morning Leon Herschberger of National RV Refrigeration arrived and
> we left the coach with him to rebuild our Dometic 3 way refrigerator.
>
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
Re: [GMCnet] VAPOR LOCK and FUEL BOILING. [message #139838 is a reply to message #139834] |
Thu, 18 August 2011 14:58 |
Ray Erspamer
Messages: 1707 Registered: May 2007 Location: Milwaukee Wisconsin
Karma: -3
|
Senior Member |
|
|
I have a 2652.....what's the recall all about Ken ?????
Ray
Ray & Lisa Erspamer
78 Royale "Great Lakes Eagle"
Center Kitchen TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
----- Original Message ----
From: Ken Henderson <hend4800@bellsouth.net>
To: gmclist@temp.gmcnet.org
Sent: Thu, August 18, 2011 2:49:24 PM
Subject: Re: [GMCnet] VAPOR LOCK and FUEL BOILING.
Don,
I can't believe you didn't make the short detour by here! We'd have had
those tanks out before the fuel could quit boiling! :-)
Glad you found Chuck and his wiser head prevailed.
I'm glad you mentioned the refrigerator. I've got a perfectly good Dometic
2652 sitting under the RV shelter that they refused to repair under the
recall -- because it was no longer a fire hazard after all the ammonia
leaked out. :-( I should take that to Goshen and have Leon rebuild it for a
spare -- or sale. Have to try to figure out a way to carry it.
Ken H.
On Thu, Aug 18, 2011 at 2:58 PM, Don Jeffers <don.jeffers@frontier.com>wrote:
> ...
Got on the road around 10:30 a.m. the next morning. It was a pretty hot
> day. After driving for a while, the coach began to stumble and shortly
> thereafter began to backfire and the engine quit.
> ...
> Chuck told me that 20 or 25 GMCers at a recent Georgia meet had experienced
> the very same symptoms and that it was VAPOR LOCK caused by the new fuels.
> ...
> Chuck was apparently correct; it was a combination of the newer fuels and
> the hot day and roadway that caused the problem.
> ...
> The next morning Leon Herschberger of National RV Refrigeration arrived and
> we left the coach with him to rebuild our Dometic 3 way refrigerator.
>
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
|
|
|
Re: [GMCnet] VAPOR LOCK and FUEL BOILING. [message #139842 is a reply to message #139838] |
Thu, 18 August 2011 15:05 |
Ken Henderson
Messages: 8726 Registered: March 2004 Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
The 120 vac heating element supposedly is too big for the job and causes the
tube to crack. If I understand correctly, they just put a heat shield
between the heating element and the tube. Apparently most people who had
failures got warranty repairs, but by the time mine quit (quite a while
after I heard of the recall) they figured out that loophole: No gas, no
hazard.
You'll have to check the Dometic site for S/N range, etc.
Ken H.
On Thu, Aug 18, 2011 at 3:58 PM, Ray Erspamer <78gmc-royale@att.net> wrote:
> I have a 2652.....what's the recall all about Ken ?????
>
> Ray
>
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
|
Re: VAPOR LOCK and FUEL BOILING. [message #139849 is a reply to message #139844] |
Thu, 18 August 2011 15:49 |
jhb1
Messages: 303 Registered: February 2004
Karma: 0
|
Senior Member |
|
|
WD0AFQ wrote on Thu, 18 August 2011 16:19 | Thanks for the report. Leon is a great guy if you need a refer fixed. Glad you found him.
Jeremy, you are correct, an electric pump will not always overcome vapor lock. I have had it twice and have an electric pump and fuel injection. Once the outside temp was 107. The second time it was less than 90 and I was in Alabama. May just be that some fuel is more prone to cause this problem. I am going to install the in the tank pumps next. That may help more than the inline pump I have. We will see.
Dan
|
Had the same problem the beginning of July driving thru Alabama and Florida going to the shuttle launch had to stop every hour or so and hose down the fuelntanks with water or put in cooler gas. I measured the temp a few times when this happened and the underside of the tanks were between a high of 154 and low of 141 and yes you can hear the fuel boiling. As a note I am running a fuel injection system so the pressurizing doesnt seem to help
John H. Bell
77 Royale; QuadBag,Manny OneTon,Honda EV4010, FITech
Montreal Qc.
|
|
|
|
|
|
Re: [GMCnet] VAPOR LOCK and FUEL BOILING. [message #139872 is a reply to message #139857] |
Thu, 18 August 2011 17:20 |
Jon payne
Messages: 495 Registered: May 2008
Karma: 1
|
Senior Member |
|
|
Hi Don,
Sorry to here about your difficulties. Just a thought here, I had similar experience this summer as well and it turned out that the ignition module was going bad. The first trip we took this summer I thought at the time we were experience vapor lock. When this started it would begin by sputtering then would quit. I'd pull over to the side of the road, wait a 30 minutes or so then it would start right back up only to quit again a few miles down the road. Then, some miles later we reached or destination. Later that evening we returned home, 2+ hours drive with no problems. I was convinced we experienced vapor lock. Our second trip this summer, which was over 3 hours in very hot weather, just a few miles from our destination it started to sputter again then quit. Pulled over and waited 30 minutes and then it started again. Another few miles it quit again and this time for good. No spark! Changed the ignition module and no problems since.
I'm not saying this is what you are experiencing but it sounded similar to what we went through.
Jon
Jon Payne
76 Palm Beach
Westfield,IN
|
|
|
|
|
|
ign. module [message #139944 is a reply to message #139886] |
Thu, 18 August 2011 22:58 |
bukzin
Messages: 840 Registered: April 2004 Location: North California
Karma: 0
|
Senior Member |
|
|
Gene,
I see several options in the 'parts interchange index'
booklet (mine is dated Spring 2009)
Lots of folks seem to like the Echlin (Napa) # TP45
Can we assume you prefer the Delco D1906 ?
Bukzin
1977 Palm Beach
|
|
|
Re: [GMCnet] VAPOR LOCK and FUEL BOILING. [message #139945 is a reply to message #139921] |
Thu, 18 August 2011 23:09 |
djeffers
Messages: 219 Registered: June 2004
Karma: 2
|
Senior Member |
|
|
[quote title=Robert Mueller wrote on Thu, 18 August 2011 21:25]Don,
Could you please provide some more info re this:
"I hope GMCers don't have to go to a Jaguar type solution and put AC
evaporators in the tanks to deal with the new, improved fuels."
Regards,
Rob M.
Rob,
My reply about AC evaporators in the fuel tank Jag type solution was a tongue in cheek reference to what I see as the occasional Jaguar needless complication. Other Jag owners might understand.
I have a Jag XJS 12, converted to a Chevy 355 engine, that Jaguar ran a cooling line, AC I believe, through a fuel can under the hood. It seemed to soak up heat rather than cool, so I took it out. It's been so long since I looked at that device I'm not even sure how it was set up.
A couple of other Jag items I thought were not good solutions were:
1. An electric cooling fan for the battery on a '70s sedan, an XJ6 I believe, with the battery stuck over in a very hot corner. I know of one battery that exploded on a hot summer day when the colling fan motor failed.
2. My 6 cyl E-Type had an automatic fan belt tensioner pulley that the bearings would just die. I took the automatic tensioner off and adjust the fan belt the conventional way with the alternator. No further bearing failures. What ain't there ain't gonna break.
Just pokin' fun at my Jaguars. Some other Jag owners have similar feelings. No offense intended. Maybe I've strayed too far off the GMC topic. If so, I apologize, but I do tend to look around at problems and solutions.
Thinking about the large, flat GMC fuel tanks with their high surface to volume ratio and the large flat bottom surface closely exposed to the radiant heat of the roadway and exhaust led me to the humorous (I thought) Jaguar-esque idea of putting a small AC evaporator in each tank to help solve vapor lock problems.
If radiant heat from the roadway and the exhaust system is a significant source of fuel temperature rise causing the vapor lock problem, then maybe full coverage aluminum shields with an airspace between the shields and tanks might be a help.
Which brings up a related topic I would like to raise in another thread, the very high temperatures of the GMC exhaust system.
The GMC fuel tanks offer some interesting challenges.
Don
|
|
|
|
Goto Forum:
Current Time: Tue Oct 01 19:28:09 CDT 2024
Total time taken to generate the page: 0.13932 seconds
|