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| Starting Problems | |
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| Tweet Topic Started: Apr 13 2009, 05:40 AM (563 Views) | |
| gwy | Apr 13 2009, 05:40 AM Post #1 |
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My 1953 6V ex swiss CJ3B starts well with engine hot and cold. But when driving downtown after shopping for around 60 minutes it wont start at all. I have to open the hood, try and try again and at last after 15 minutes the engine starts immeadiatly. I have the impression, that gas vapouring is the cause and cooling down with the open hood is the reason for the new successful start. Does a new gas pump with manual lever help ? Are there any other suggestions ? Greetings from Germany from Gunter |
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| oldtime | Apr 13 2009, 09:27 AM Post #2 |
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Gunter, As you know the engine basically must have fuel and fire to start. FUEL CONCERN The fuel supply must remain fluid all the way into into the carburetors fuel well. Fuel fluidity is effected by the fuel temperature; even by temperature within the tank. Fuel fluidity is effected by atmospheric pressure. High altitude decreases fuel pressure. It is important that the fuel supply line from the tank be located similar to original design. Locate the supply line away from the engine heat and especially the exhaust system. See: http://www.film.queensu.ca/cj3b/Tech/FuelLine.html There you may also read how a mechanical fuel pump has several advantages when its compared to an electrical fuel pump. However; the main disadvantage is that an engine mounted fuel pump can absorb heat from the engine. This is especially a concern during slow driving conditions or with restricted engine cooling. As the fuel enters into the mechanical pump the supply line pressure is reduced. This is the point where vapor lock generally initiates. The solution is simple... keep the fuel cool; away and perhaps insulated from heat. FIRE CONCERN Intermittent ignition may also be caused by temperature. Often times a weak condenser is prone to malfunction due to high temperature. Condenser capacitance can be tested with a meter or simply replace with another condenser. If intermittent starting re-occurs try cooling the mechanical fuel pump or replace the condenser. A new mechanical fuel pump will only help if the existing pump is faulty, producing inadequate pressure. |
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Currently building my final F-134 powered 3B . Rock Crawler using factory parts from the Willys Motors era (1953-1963) http://s4.zetaboards.com/CJ3B_Bulletin_Board/topic/30228766/1/#new | |
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| Larry (TX) | Apr 13 2009, 07:48 PM Post #3 |
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A bad coil can also cause the problem you describe, (after a short cooling off period, it'll usually work; do what Ken suggests first by replacing the inexpensive condensor, and if afterwards the problem still exists, you might try replacing the old coil with a new one). Larry S. |
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Larry Steed Pearland, Texas '53 Willys CJ3B '52 Willys M38 '86 Chevy M1009 CUCV (K5 4x4 Military Blazer) M100 1/4 ton jeep trailer M416 1/4 ton jeep trailer (2 ea.) M101 CDN 1/4 ton jeep trailer | |
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| Don | Apr 13 2009, 09:08 PM Post #4 |
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Gunter, I think you need to find out for sure if you have a fuel problem before replacing any parts. A can of starter fluid can help. The next time your rig won't start and you think it's due to hot fuel, remove the air breather hose and put a one second shot of starter fluid into the carburetor. It should start right up. If it still doesn't start then you 'might' have an electrical component overheating. However, if your rig runs ok for a few seconds, then your hunch of gas vapouring needs to be checked. Check the routing of your fuel line and your exhaust pipe. The problem might be caused when you park a hot engine. When you're moving, the air flow would keep a fuel line cool, but when you park, the hot air off an exhaust pipe rises straight up and could cause vapor problem. Good luck, keep us posted. |
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Don Norris Southeast, NC 1953 CJ3B 1959 Jeep Pickup 195? M100 trailer ~~~~~~~~~~~~~~ The trail never ends ~~~~~~~~~~~~~~~ If lovin' Jeeps is wrong, I don't wanta be right. | |
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7:49 PM Jul 10