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Old 02-11-2020, 11:13 PM   #1
hessam69
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Default Slow hot restart

Hi,

My 1984 240 with B23E engine, has difficulty sometimes with starting when the engine has been left for around 5 minutes or more. In general, it takes a little longer to start than other kjet 240's I have.

Once cranking for a couple of seconds or more, it slowly starts firing up and coming to life, however I'm used to them starting pretty instantly, or not long after the starter has turned the engine. Could this be a resting fuel pressure problem?
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Old 02-11-2020, 11:13 PM   #2
hessam69
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If I shut down the engine and restart it immediately, there is no problem.
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Old 02-12-2020, 01:18 AM   #3
James M
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Sounds like fuel pressure to me
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Old 02-12-2020, 04:44 AM   #4
hessam69
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I think you're right. What do you think is doing it?
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Old 02-12-2020, 08:53 AM   #5
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Quote:
Originally Posted by hessam69 View Post
I think you're right. What do you think is doing it?
When it used to happen to me, we had MTBE instead of ethanol added to the fuel, and the check valve at the output of the main pump failed when the spring rusted. I only had to replace those check valves that came with my used cars, not those I installed, probably because we practice keeping the fuel tanks full to minimize condensation in the tank.

Shorter answer: Measure the fuel pressure after 20 minutes. Minimum pressure should be half the operating pressure to prevent vapor lock of the main pump. Failure to maintain rest pressure as the engine compartment cools can be the check valve, the regulator, or leaky injectors. Edit: B23E maybe forget what I said about the regulator.
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Old 02-13-2020, 08:15 PM   #6
dl242gt
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Another hot start factor is the fuel accumulator. It is there to help with the rest pressure decay along with the fuel pump check valve. The diaphragm inside of them gets stiff and doesn't absorb fuel pulsations or properly let the rest pressure decay. Take a look at it physically. If it's very corroded on the outside then the inside probably is bad. Also some of them are vented and have a small hose going back to the fuel tank. If you remove that hose and fuel comes out. It's bad.
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Old 02-14-2020, 06:48 AM   #7
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Another hot start factor is the fuel accumulator. ...
Yes, accumulator. I was totally immersed in the memory of my B23F (LH2 fuel) when I posted above.
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