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#1
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Why is cold start RPM lower?
Hi,
At cold start, my RPMs are 50-100 at least lower than where they should be. This will sometimes cause a stall, or at minimum poor running. Hit the throttle and bump it up to near 1000, and then it will settle back at 750 and be there until the next cold start. What gives with that? Why do the RPMs start low and then require throttle (or a lot of time) to get to where they need to be? Thanks!
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Current Diesels: 1981 240D (73K) 1982 300CD (169k) 1985 190D (169k) 1991 350SD (113k) 1991 350SD (206k) 1991 300D (228k) 1993 300SD (291k) 1993 300D 2.5T (338k) 1996 Dodge Ram CTD (442k) 1996 Dodge Ram CTD (265k) Past Diesels: 1983 300D (228K) 1985 300D (233K) |
#2
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... fuel burns poorly when the block is cold.
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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread "as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do! My drivers: 1987 190D 2.5Turbo 1987 190D 2.5Turbo 1987 190D 2.5-5SPEED!!! 1987 300TD 1987 300TD 1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere! |
#3
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Sure, that's fine, but it ONLY happens on my 82. Not my 81 or any others.
It is one thing to have combustion inconsistencies, hard starting, etc. This is a one time thing and the instant after I give it throttle, it never comes back. A poorly combusting cold engine will revert to the issue if the throttle is pressed then instantly released back to the normal state. Mine is A-OK after bumping the idle up via pedal.
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Current Diesels: 1981 240D (73K) 1982 300CD (169k) 1985 190D (169k) 1991 350SD (113k) 1991 350SD (206k) 1991 300D (228k) 1993 300SD (291k) 1993 300D 2.5T (338k) 1996 Dodge Ram CTD (442k) 1996 Dodge Ram CTD (265k) Past Diesels: 1983 300D (228K) 1985 300D (233K) |
#4
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Sticky linkages?
Oil too thick at first? Check those out and see if they help... You can also rig up the afterglow system as discussed on the board. It really helped my '81 and also the '86 run better cold in the winter...
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"I have no convictions ... I blow with the wind, and the prevailing wind happens to be from Vichy" Current Monika '74 450 SL BrownHilda '79 280SL FoxyCleopatra '99 Chevy Suburban Scarlett 2014 Jeep Cherokee Krystal 2004 Volvo S60 Gone '74 Jeep CJ5 '97 Jeep ZJ Laredo Rudolf ‘86 300SDL Bruno '81 300SD Fritzi '84 BMW '92 Subaru '96 Impala SS '71 Buick GS conv '67 GTO conv '63 Corvair conv '57 Nomad |
#5
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does it do it, if before you start the car, you floor the accelerator and release?
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread "as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do! My drivers: 1987 190D 2.5Turbo 1987 190D 2.5Turbo 1987 190D 2.5-5SPEED!!! 1987 300TD 1987 300TD 1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere! |
#6
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My w201 does the same thing: it idles slow and then kicks up by itself when warmed a bit. Yours sounds like dry linkages perhaps.
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#7
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I'll have to floor and release before startup and see what happens...
__________________
Current Diesels: 1981 240D (73K) 1982 300CD (169k) 1985 190D (169k) 1991 350SD (113k) 1991 350SD (206k) 1991 300D (228k) 1993 300SD (291k) 1993 300D 2.5T (338k) 1996 Dodge Ram CTD (442k) 1996 Dodge Ram CTD (265k) Past Diesels: 1983 300D (228K) 1985 300D (233K) |
#8
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I'd check the linkages.
On my 85, the car idles a bit slower when completely cold. However once warm you can hear the clack clack clack speed up slightly. Cold engines make all sorts of weird noises.
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-Typos courtesy of my mobile phone. |
#9
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Syn 5w-40 shouldn't be too thick... Will check the linkages for proper ATF residue...
__________________
Current Diesels: 1981 240D (73K) 1982 300CD (169k) 1985 190D (169k) 1991 350SD (113k) 1991 350SD (206k) 1991 300D (228k) 1993 300SD (291k) 1993 300D 2.5T (338k) 1996 Dodge Ram CTD (442k) 1996 Dodge Ram CTD (265k) Past Diesels: 1983 300D (228K) 1985 300D (233K) |
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