Author Topic: Exact fuel pressure test hookup help needed for a California 6.9  (Read 1292 times)

daantjie

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #60 on: 16 September 2020, 07:48 PM »
I use NGK BP5ES on my 6.9, works great.
Daniel
1977 450 SEL 6.9 - Astralsilber

John Moore Sr

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #61 on: 17 September 2020, 03:43 AM »
RE: Spark Plugs. In 1975  when 6.9s began rolling of the line, Euro market cars came out with Bosch W 200 T30 which was later renumbered W 6,  U.S. market  cars starting in 1977 used Bosch W 125 T30 which was later renumbered W 9 D, then to W 9 DC (copper core), then to 7511.  The 200 Euro plug has colder heat range for sustained high speed driving. The U.S. 125 plug (W 9 DC) has a hotter heat range for stop and go driving. W 9 DC plugs are pretty common on EBAY at various prices. For What It's Worth....JM Sr.                                         
1970 300SEL 3.5, 1972 350SLC Euro Parts car, 1974 350SL Euro 3.5 V8 4 speed, 1978 450SLC Euro. 1979 6.9 #4630 1979 6.9 #7003 Parts Car, 1980 450SLC Parts car, 1985 380SL...and once had 1975 6.9 #142 until JuNIOR commandeered it.

ptashek

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #62 on: 17 September 2020, 06:48 AM »
I think a lot of us here happily run the NGK BP5ES or BP6ES, depending if you want a colder/hotter plug.

If you go to the MB parts desk, you'll get a re-packaged Bosch plug. Either a W9 or a W8, can't remember which exactly.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE (history, resto)

secondslc

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #63 on: 18 September 2020, 07:10 PM »
An update...

-New plugs in, no start. Bollocks

-Noticed the air meter plate was not moving when cranking. (I was a fool and adjusted it to have a bit of a gap before installing it.) Took it all apart and adjusted it per the manual. While I was in there I made sure the fuel mix screw was adjusted so that the 8 FD ports had fuel in them but would not move. Thats baseline. No start... damn

-Counted and cranked the screw in half a turn at a time as the plugs were dry. Turned it till the plugs were wet. No start.

Alright, so now I knew I was getting fuel, and I know the metering plate is moving when cranking. I also knew the timing was right and the entire ignition system was rebuilt...except the wires as I wanted to find the right ones... So I inspected and noticed the coil was warm...

Pulled the coil wire, adjusted the fitting. And here is the result.

https://youtu.be/OmSpmBpd3oM

;D

I adjusted the fuel to about a quarter turn past baseline and it no longer popped or missed. Seems to rev freely, and knowing what I know now... the fuel system is "perfect"

Next up
-An oil change as I have probably destroyed the oil in it.
-New ignition wire set
-I need to replace the rear leveling arm, as it broke during the fuel pump replacement, and I currently am set at full stiff, can't drive it.
-My cats smolder after a few minutes of running the engine above idle. The insulation starts smoking and well... it's a cause for concern as they cook the interior too. They're either clogged or extremely full of fuel. Either way, check out the awful mess coming out of my tailpipe.
-When I take the car in to inspect the cats...I am going to have two Wideband bungs welded in pre-cat so I can understand the tune. Seems like a much more reliable way of testing than an exhaust sniffer.

Then it's on to brake lines and tires. Aged rubber is going to be my next fun chase!

Guys, I was ready to give up on this thing, thanks for the encouragement, and convincing me I was so close. I'm still a ways from "finished", but at least the car feels alive.
1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8

daantjie

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #64 on: 18 September 2020, 07:30 PM »
Niiiiice ;)
Daniel
1977 450 SEL 6.9 - Astralsilber

raueda1

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #65 on: 18 September 2020, 08:58 PM »
Awesome!  Persistence and patience paid off.  Looking forward to your next adventures.  Solid!
-Dave
Now:  '76 6.9 Euro
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

rumb

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #66 on: 19 September 2020, 05:43 AM »
Glad to hear it is sorted now. Well done!
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

John Moore Sr

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #67 on: 19 September 2020, 06:16 AM »
Awesome !!  It's always the simple things that can stump you !   Good job !!  JMSr
1970 300SEL 3.5, 1972 350SLC Euro Parts car, 1974 350SL Euro 3.5 V8 4 speed, 1978 450SLC Euro. 1979 6.9 #4630 1979 6.9 #7003 Parts Car, 1980 450SLC Parts car, 1985 380SL...and once had 1975 6.9 #142 until JuNIOR commandeered it.

revilla

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #68 on: 19 September 2020, 06:37 AM »
Bravo!!!
As somebody said before, and before, and before... spark + fuel + igt timing + mixture ratio  = combustion and running engine. It’s simple at the end of the day.  Good job.
Now you can hook up your gauge to fine tune the system.  If I remember correctly you had 0.8 bar cold control pressure. Hope I’m not confusing. That’s a bit low/rich at 20C but within range per spec. Most importantly, if it reaches 3.6-3.8 bars within 3 minutes when hot it’s ideal. For that the WUR has to be revisited (if needed). Let us know of next steps in case you need help.
Cheers
Robert
W116 1977 280SEL & 1979 280SE

secondslc

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Re: Exact fuel pressure test hookup help needed for a California 6.9
« Reply #69 on: 19 September 2020, 08:15 AM »
Thanks guys!

Bit of a hiccup, the fuel pump in my sl600 failed... lol. Guess it got envious
1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8