Author Topic: at +3000 rpm engine falter  (Read 2596 times)

lex280

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at +3000 rpm engine falter
« on: April 30, 2017, 16:53:57 »
Hi Guys,

next problem :-)

At +3000rpm my engine falters. Only when hot and not al the time.
My spark plugs look great.
The injection pump has been overhauld 2 years ago.
Also, when i have to start cold it take almost 10-15 seconds.
Cold start valve is working properly.
Fuel pressure is ok.
Fuel filter is as new.
Fuel tank has been cleaned.

Anyone familair wih this?


TheEngineer

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  • '69 280SL,Signal Red,
Re: at +3000 rpm engine falter
« Reply #1 on: April 30, 2017, 17:34:48 »
Sounds like your electric fuel pump s not delivering enough fuel. Disconnect the fuel line at the engine, turn on the fuel pump and measure fuel flow. Should be about one litre per minute. Fuel filter may be plugged. You would not run well if you don't get enough beer. A.Dalton says it should be on liter per 15 sec. I wrote from memory and should have looked it up! Very sorry about this.
« Last Edit: May 01, 2017, 03:15:24 by TheEngineer »
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Tyler S

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Re: at +3000 rpm engine falter
« Reply #2 on: April 30, 2017, 18:49:09 »
Does it do this under load or also reving the engine in neutral?
Check the points/dwell and coil. Also check for spark during your long crank event.  Coils usually act up when their hot and also when voltage is low (during cranking)
« Last Edit: April 30, 2017, 18:55:06 by Tyler S. »
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lex280

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Re: at +3000 rpm engine falter
« Reply #3 on: May 01, 2017, 12:07:31 »
thanks!

will check!

mdsalemi

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Re: at +3000 rpm engine falter
« Reply #4 on: May 01, 2017, 14:37:50 »
...more on electrical...

Check the integrity of your wires. Are you running copper core, no resistor wires? If not, the possibility is that you have a breakdown in one or more of the wires.

Also, check the cleanliness of the wires. A layer or coating of dirt, grime, etc. on the outer surface of the wires can cause ignition breakdown particularly at higher RPM.

(yeah, I've had both of these issues over the years with one or more cars...)
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
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