Author Topic: fuel injection pump  (Read 720 times)

Johnpin

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fuel injection pump
« on: December 20, 2019, 19:55:11 »
Hi everyone. I need some help. After a two year restoration on my 1967 230SL and thousands of dollars spent I still have a problem with cold starts and I have been told by two mechanics that its the injector fuel pump which I have had serviced but not rebuilt. Anyone knows where and who does rebuilds or exchange's on injector pumps and should I look at updating the injector pump to a 280sl one as I am told they are a lot better.
Any help will be appreciated

Regards John

naristodemou

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  • 280SL Auto 1970 W113, 380SL Auto 1982 R107
Re: fuel injection pump
« Reply #1 on: December 20, 2019, 20:51:16 »
Hi John,

With all due respect to your mechanics, I would first look at all the cold start devices like cold start valve, thermo switch etc before going into the FI pump. They rarely go wrong unless somebody has been messing up with it....

Nicolas Aristodemou
Nicosia - CYPRUS
280SL Auto 1970, US spec (W113)
380SL Auto 1982, EU spec (R107)

Benz Dr.

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Re: fuel injection pump
« Reply #2 on: December 20, 2019, 23:21:21 »
You have to stick to a 230SL injection pump. Each engine has its own pump designed to work only with that system. What are your problems right now?
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

Pawel66

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Re: fuel injection pump
« Reply #3 on: December 21, 2019, 10:33:45 »
I would have thought if youe are right after restoration, it seems like a natural step to go through the Linkage Tour: https://www.sl113.org/wiki/Restricted/Linkage-tour

Or specifically engine starting aid (if this is your issue): https://www.sl113.org/wiki/Restricted/Engine-starting-aid-tour

That may prevent you from huge expenses and going in the wrong direction.

You need to be a Full Member to access some of those, but I am sure you will soon find this is the best investment in your car that you could make.
Pawel

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

ja17

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Re: fuel injection pump
« Reply #4 on: December 21, 2019, 14:43:45 »
After checking all the starting aids, I would hook a temporary switch to the intake CSV. By experimenting with this you can help diagnose the problem.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Desertpagoda

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Re: fuel injection pump
« Reply #5 on: January 15, 2020, 00:08:45 »
exactly, next time you think it will struggle to start, bring the fuel pressure up, then hot up the cold start valve for 3-4 seconds and crank. if it starts look at the cold start system
kb

ctaylor738

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Re: fuel injection pump
« Reply #6 on: January 24, 2020, 01:46:23 »
You should be glad your mechanics are not doctors recommending a heart replacement because of indigestion.

The 230SL has a cold start valve and a solenoid on the injection pump (moves the pump to full rich) to help with starting.  Both are controlled by relays.  The cold start relay needs ground from the thermo-time switch to work properly.

Suggest you join as a full member, download the color wiring diagram in the technical manual, and take it to the mechanics.  If they can't understand it, you need to find another mechanic.

CT
Chuck Taylor
1970 280SL #13027 (restored)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

Benz Dr.

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Re: fuel injection pump
« Reply #7 on: January 24, 2020, 05:14:49 »
You should be glad your mechanics are not doctors recommending a heart replacement because of indigestion.

The 230SL has a cold start valve and a solenoid on the injection pump (moves the pump to full rich) to help with starting.  Both are controlled by relays.  The cold start relay needs ground from the thermo-time switch to work properly.

Suggest you join as a full member, download the color wiring diagram in the technical manual, and take it to the mechanics.  If they can't understand it, you need to find another mechanic.

CT

Well, that sure is good, simple, advise. :)
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn