Author Topic: FIP Check  (Read 1932 times)

JJ65SL

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FIP Check
« on: July 28, 2021, 14:17:03 »
Many thanks to all who have provided valuable information to me as I strive to perform many of the necessary maintenance items on my 65 230 SL. 

In order to determine if the FIP is providing fuel to the injectors, which are new, I have followed the advice provided by Joe Alexander in a previous post. I removed the plugs and disconnected the fuel lines at the injectors. Fuel is exiting the fuel lines. The fuel appears to be exiting in a pulsating manner. How strong should the fuel flow be, given that the lines are open?

Thanks,

John
John
1965 Euro 230 SL 4 Speed
‘84 purchase while stationed in Germany
124,000 original km/condition
717G/206

ja17

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Re: FIP Check
« Reply #1 on: July 28, 2021, 22:09:28 »
Fuel emerging from the IP is a very small quantity with low rpms during cranking. More throttle, colder temperatures and higher rpms will increase the quantity. I am not sure what the pressure of the fuel exiting the IP injector lines but the gasoline injectors open around 40 lbs I believe. Be sure that the fittings on the IP are torqued to specs. If they are too loose fuel will not emerge from the fittings. Don't over-torque them or you can actually crack the aluminum pump housing.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

JJ65SL

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Re: FIP Check
« Reply #2 on: July 29, 2021, 00:18:24 »
Joe, thank you very much for your reply. Based on your comment and the amount of fuel exiting the opened fuel lines at the injectors while cranking, I think the FIP is working properly. Now I need to figure out why the engine won’t start, even though there is spark, new plugs, linkage is properly set, new OEM fuel tank, fuel filter and most recently a Pertronix II Igniter and Flamethrower II. There has been some mild backfiring at start attempts. Any comments would be greatly appreciated. 

John
John
1965 Euro 230 SL 4 Speed
‘84 purchase while stationed in Germany
124,000 original km/condition
717G/206

ja17

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Re: FIP Check
« Reply #3 on: July 29, 2021, 21:16:44 »
A lot of cranking is required to fill and prime those long injector lines. Remove all the spark plugs, loosen the injector lines at the injectors and crank the engine at full throttle until fuel emerges from each loose line,
at each injector. Tighten each line when fuel emerges. When all six lines are primed and tightened, re-install the spark plugs and the engine will start!
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

JJ65SL

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Re: FIP Check
« Reply #4 on: August 08, 2021, 21:52:10 »
Joe, thanks for the additional pointers.  I have been traveling for over a week and just got back to trying to get the car started.  First, I checked to make sure the intake start valve was functioning and it is spraying into the intake manifold as it should.  The fuel supply to it is very strong.  I primed the fuel lines to the injectors as you suggested and tightened them to the injectors at the appropriate torque.  After installing the plugs, I tried to start it but I am only able to get an occasional backfire.  Any further suggestions would be greatly appreciated.

John
John
1965 Euro 230 SL 4 Speed
‘84 purchase while stationed in Germany
124,000 original km/condition
717G/206

Kevkeller

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Re: FIP Check
« Reply #5 on: August 31, 2021, 03:42:41 »
Did you move the distributor and knock the timing out?

1970 280 SL

Pawel66

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Re: FIP Check
« Reply #6 on: August 31, 2021, 06:19:02 »
Very similar though as Kevkeller. Or: have you been removing ignition leads? Are they in proper order on the distributor?

Also: after prolonged cranking with no start - are the spark plugs wet and smelling gas? Or rather dry?

Last one - timing of the FIP, but even with the timing off 180degree, the engine should work. So rather ignition topics, I would think, are to be checked.
« Last Edit: August 31, 2021, 06:25:24 by Pawel66 »
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class