Author Topic: Hair trigger accelerator  (Read 3924 times)

georgem

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Hair trigger accelerator
« on: August 14, 2010, 22:19:51 »
Some suggestions please,

I recently replaced all the ball joints in the accelerator linkage and as a consequence was able to finally undertake the linkage tour successfully. She is running very sweetly.  HOWEVER (and there always is a however), a consequence of the above is that the accelerator pedal is too responsive.  pressing the accelerator a hairs width takes the revs from idle to about 2000 rpm which is really challenging to get a smooth clutch release. Please note that I am very familiar with manual cars, having owned several Healeys. MGs and a Jag. Frankly I find it an embarrassment to start of with either a gob full of revs or shame oh shame, a stall.

My question is, therefore, is there a setting or adjustment that I can make to give a little more travel at the start of the accelerator travel to give me an even chance of a respectable start.

Cheers
George McDonald
Brisbane
230 Sl
1973 VW Kombi Single Cab Ute
2022 Volvo XC 40 Pure (100% electric)

ja17

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Re: Hair trigger accelerator
« Reply #1 on: August 15, 2010, 00:45:31 »
Hello George,

Sounds like your venturi flap is binding just a bit.  It may be adjusted too tight and is binding. When it does let loose the accelerator is forced too far open causing hight rpms. Another possibility is that the first linkage (the  small one from the pivot on the intake which attaches to the cross-over rod) is adjusted too short and is "high centered" (requiring too much pedal pressure to get past top dead center). You may have to change the length a bit.

Otherwise, make sure all the linkages are free and work easily.  Also note that the return spring on the firewall ( near the brake booster) has several positions it can attached to on the linkage arm. I believe the position closest to the firewall should require the least amount of pedal pressure.

Sounds like you are close.  Keep at it, I am sure it a simple fix. Keep us up to date.

Joe Alexander
Blacklick, Ohio
« Last Edit: August 15, 2010, 00:47:20 by ja17 »
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

georgem

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Re: Hair trigger accelerator
« Reply #2 on: August 16, 2010, 07:00:20 »
Thanks Joe - i`m on to it.

George
George McDonald
Brisbane
230 Sl
1973 VW Kombi Single Cab Ute
2022 Volvo XC 40 Pure (100% electric)

georgem

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Re: Hair trigger accelerator
« Reply #3 on: August 24, 2010, 07:32:12 »
Joe,

Taking one thing at a time, I reset the accelerator return spring to the inner - softer position and it helps a bit. Next step is the accelerator linkeage.

Re the next step of adjusting the linkeage. Won`t shortening the linkeage you suggest change the setting for the length of the rod from the cross over to the venturi - you have always stressed this as critical?

George
George McDonald
Brisbane
230 Sl
1973 VW Kombi Single Cab Ute
2022 Volvo XC 40 Pure (100% electric)

ja17

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Re: Hair trigger accelerator
« Reply #4 on: August 24, 2010, 23:36:42 »
Hello George,

Change the length of the small center linkage rod just enough to get it past top dead center. I think lengthening it could be the right action (correction to previous post) ? 
Change only as needed.

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