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Re: Hot start problem, vaporlock? Posted by DougM [Email]  (#211)  [Profile/Gallery]
(more from DougM) on Mon, 8 Mar 2004 21:11:00
In Reply to: Hot start problem, vaporlock?, LJB, Mon, 8 Mar 2004 17:21:44 Members do not see ads below this line. - Help Keep This Site Online - Signup |
That test you performed did nothing but fill the cylinders up with gasoline, that is why is was flooded when you went to start it.
The manual says that if you are having starting difficulties with a warm engine, it is possible that the fuel pressure in the lines is excessively low and can cause vapor lock in the fuel lines. For this test you would need to hook a fuel gauge to the system and see if the pressure drops off after the engine is shut down. Pressure drop is acceptable, but it is not allowed to go lower than 14psi after sitting for 20 minutes. Some possible places for leakage...control pressure regulator, non-return valve at the fuel pump, cold start valve, line pressure regulator, injection valves, or external leakage. Pulling the injectors, cold start valve, and looking for external leaks is easy to do and pretty straight forward. I have no clue how to check the other things yet, or haven't ran across it in my reading so far.
I also read on a k-jet site that if the contacts in the thermo time switch were burnt closed, this would allow the cold start valve to inject gas even when the engine was warmed up. Maybe pull the plug on it and see if the problem goes away. This might verify a bad switch.
Another thought...looking at the warm up regulator, if the spring inside it was broken, the control pressure on a warm engine could be too low, causing the control plunger in control pressure regulator to allow higher fuel pressure, which would cause too much fuel to be injected in a warm engine. I guess you could test this out with a gauge also. The pressures are listed in the manual(control pressure warm engine, 48-54psi). If by depressing the pedal and opening the butterfly more, to allow more air to enter the intake when cranking, to mix with the larger than allowed fuel....correct me if this sounds out of line, but maybe it is getting too much gas when warmed up.
posted by 68.68.16...
, Fri, 12 Mar 2004 06:06:26, Mon, 8 Mar 2004 21:11:00 <-- Viewing This Message, Tue, 9 Mar 2004 10:51:10, Tue, 9 Mar 2004 11:41:23, Mon, 8 Mar 2004 19:54:48
, Tue, 9 Mar 2004 19:28:32
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