I just want to add something to this that always bothered me . People talk of "vapor lock " and one sees wrapped fuel lines and lots of cures centered on the line after the fuel pump . ( chevy guys) However if you think about it , it makes no sense compared to the known physics . Vapor lock happens just like water boiling . If you reduce pressure over water it boils below 212 . If you raise pressure (15 Psi cap ) it might be 260 . Fuel after the pump is under 5 psi pressure , it cannot boil ( in my opinion ) but fuel before , or in the pump is under suction / vacuum .. It will boil easily ---turn to vapor and thus stop pump action . Car stalls / slows . But consider IF it boils in pressure line to carb , think about what would happen ? Feed Needle in carb is open ,( needs gas) any gas or vapor is IMMEDIATELY pushed out of open end line by liquid from pump and is of no consequence . So I think vapor lock was caused in 20's by hot fuel pump or hot suction side intake line between tank and carb , running near or on engine ---not the line ( which may be very hot ) from pump to carb . Ethanol aggravates all this . It simply cannot do that , clog the carb pressure line with vapor , as one end is open ( it is ) and if pump is working liquid is coming to push out vaporized gas instantly . Like air in garden hose . Understanding all this is worth pondering ---as real problem gets mixed up with misunderstood folklore and imagined problem ? Tony mentions bleed type mopar fuel filter , line back to tank ,,that works well by rapid flow through pump and thus cooling suction line . Electric pumps by pressurizing whole line . In my personal experience fuel flow problems are 99% caused by gas tank crap getting into pump valves ( huge intermittant problem ) or clogging sock in tank . Or fuel line to pump . Then flow drops . and it gets hot at pump and the high suction due to clogged sock in old tank ( "cleaning tank " does not stop this , back 2-3 k miles later , especially if car sits -- ) nor does lining it work , in my experience .. If it rusts once it does again fast , alcohol holds water now --and liners fall off inside . I now add a filter just ahead of pump , routinely . Not all roses ( ? Restriction--but have seen no loss of power with new filter at WOT ?) but problems gone . JY 's F stopped with me driving it back from Pa meet , gradual power loss ,it had this described filter ahead of pump set up ---we changed it by side of road -- 8 miles from home on 2k mile trip ! zoomed away afterwards .. Everything exactly same on hot 90 degree day . It was actually physically HEAVY with black tank crap filling it . So "vapor lock " might be an incorrect catchall .... Those who try to help say " vapor lock ? " Or really maybe it is caused by high suction vacuum activated boiling due to restricted inlet in tank . Last ---I had collapsed tank on 57 dodge D500 in 61 due to wrong cap , for sure this happened , so all mopar tanks are not vented outside of filler . The vent runs back into neck near top . 57 Dodge stopping dead was attributed by those in the know to vapor lock in summer and water in gas in winter . Both dead wrong , but being young put gentle heat from torch on line in winter ( it started after wards --as vacuum faded , reinforcing this particular bs)One day after two years of intermittant hassle tank made a big noise as it contracted , opened cap , big whoosh . Wrong cap . Right cap I think had flapper type arrangement to let air in though about .060 hole , but not let vapor out . Still learning . 1) Buy new tank if in question -- cheap now 2) remove sock if #3 3) add filter at pump inlet or tank outlet . ( brings up plastic ones ... Smile.--I mean you can see in and no pressure --metal ..guard around it ? Best for this is 3/8 moroso stainless mesh race filter about 6 " long .. You can open and clean , zero flow restriction but 80 $ My 03 , john
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When I moved back to PA from SC, my wife drove my 69 Dart GT convertible up I-95. The first leg went fine, but after stopping for gas, the Dart wouldn’t run well. It stumbled almost to the point of stalling. We stopped at a rest stop, opened up the moving van, and found her bag of clothes pins. I put a bunch of clothes pins onto the fuel line, between the filter and the carb. They absorbed some heat, and it ran flawlessly for the rest of the trip. Mark
Carl is correct when blocking there should be at least a small hole to warm the carbs. These carbs are outboard and do not get the heat from the engine that is necessary to help gasoline mist to merge with air. Too much heat boils the ethanol in what they now call gasoline. In my experience a bad accelerator pump will impact both cold and hot performance. There could still be a problem there, but I think Tony might have the right diagnosis with suspecting some degree of vapor lock. On the heat pipes, we had some discussion at Macungie (John Grady, Jean-Yves, Lynn, Jamie et. al.) and the consensus seems to be that with the headers the heat pipes should be blocked but drill a small hole in each block off plate to allow a little heat to help while the engine is cold. When hot, plenty of heat should induct up to the carbs anyway. Having unblocked heat pipes might be adding to the problem perhaps, but Iâ•˙m not sure. Sent: Friday, August 07, 2015 8:49 AM Subject: RE: [Chrysler300] Road trip UPDATE final Tanks Charles for the feed backÂ∑
No, I do not have one of those installed, been kind of wondering along those
lines my self as it is a bear to start after sitting for a week or more.
I have to prime the carbs, else risk grinding the starter too long. Last
year ,I had to replace one of the acc pumps that had turned inside-out,
wondering I I may have another problem like that.
Was tempted to pull them out at the meet but thought better of it
Wondering if removal of the inner fender liner cutout would help any?
Did not have this problem last fall during the US Hwy 6 tour, but that was
in Oct and temps were much cooler.
This is the 1st long distance hot weather trip for this engine.
I might add, and some of the members know this, tat I am running 63-64 Ram
headers on this unit with het riser pipes connected and automati chokes.
The heat riser pipes are not blocked
Dave
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On
Behalf Of 'Charles Clark' flatheadeng@xxxxxxxxxxx [Chrysler300]
Sent: Friday, August 07, 2015 8:33 AM
To: 'David Schwandt'; 'chrysler300@xxxxxxxxxxxxxxx Club'
Subject: RE: [Chrysler300] Road trip UPDATE final
Do you have an electric fuel pump such as the Carter rotary electric pump?
That can make all the difference in the world when it comes to fuel
starvation due to vapor lock. I am a very active member of the Early Ford V8
Club here in Denver and all the cars that are driven on tour have an
electric pump installed otherwise they stand no chance on hot days. I also
have this pump on my C300 and it behaves perfectly on our high altitude 95
degree days.
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On
Behalf Of 'David Schwandt' finsruskw@xxxxxxxxxxxxxxx [Chrysler300]
Sent: Friday, August 07, 2015 7:10 AM
To: chrysler300@xxxxxxxxxxxxxxx Club <Chrysler300@xxxxxxxxxxxxxxx>
Subject: [Chrysler300] Road trip UPDATE final
Good morning USA!!!
First off, Carolyn, Melissa, out probably youngest and newest member BTW,
would like to thank Tony and Crew for wonderfully memorable meet.
Pulled off in 1st lass all around, THANK YOU!!!
Rolled into the house at around 4PM yesterday, 8/6Â∑ Todays history ?? What
is significant about 8/6??
Had rain from Springfield, OH clear thru Indiana
Total miles for the dayÂ∑535 with MPG at 12.72Â∑not bad for a fresh engine
w/2500 miles on it so far??
Now for the discomforting partÂ∑
The F rubs good when cool, like in the morning, 1st off, for about 15-20
minutes.
Then as soon as everything gets up to temp, it will start in with a stumble
when accelerating, kinda like it‚s running out of gas.
Had this problem on the way out alsoÂ∑Â∑
But if I drive like there is an egg under the foot feed, we can get along
just fine.
Thought it was the non-vented gas cap I have on it, so we removed that once
the fuel level got down some, no change.
Stopped for lunch and left the hood up for Â∏ hr, ran great again for a few
miles then same old thing again.
Has got to be under hood heat related to lousy gas.
Was good to get back to IA and a Casey‚s where most have non-alcohol gas and
the pumps are labeled as such.
Filled up at Davenport, added 8oz of Marvel mystery oil along with the
„valve save‰ stuff I have used for years and took off, no change.
Topped off w/non-alcohol gas at home and parked it.
Going to change the fuel filter and go out this AM while it‚s still cool and
see what happens now that I have a full load of „decent‰, albeit low octane
gas and see what happens.
One fellow I met at a fuel stop mentioned I should try a different heat rang
plug.
I am running NKG‚s at present
Other than that, had a good trip home with a side excursion to the flight 93
memorial (still under construction) at Shanksville, PA. Another „moist eye‰
experience as was all of Gettysburg. Both, must see places for any „True
American‰
[Non-text portions of this message have been removed]
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