Author Topic: Motor stalls out when it is hot and you put it in gear  (Read 2094 times)

Cole

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Motor stalls out when it is hot and you put it in gear
« on: June 09, 2023, 23:44:44 »
Hi,

The car has an excellent motor and performs very well.
When motor is hot and the car is in neutral or park, the motor idles fine.
But when it is put in gear, the motor stalls out. Mechanic has tried adjusting timing and idle, but this keeps happening.
What's different about putting a hot motor in gear that would make it stall out?
Any suggestions?

Thanks!
Cole
'69 280SL, 40G Black/Burgundy Interior

teahead

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #1 on: June 10, 2023, 00:02:39 »
Mechanic did the "Linkage Tour"?

1970 280SL auto, AC - aka "Edelweiss"

Lorsar

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #2 on: June 10, 2023, 00:10:46 »
What is the idle rpm in park or neutral when cold vs when hot?
Lori
1968 280SL (US)

Cole

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #3 on: June 10, 2023, 00:13:33 »
What is a linkage tour?
Thanks.
Cole
'69 280SL, 40G Black/Burgundy Interior

Lorsar

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #4 on: June 10, 2023, 00:57:21 »
The Linkage tour is detailed step by step instructions for adjusting the linkage.
It is in our tech manual (along with a ton of other great info) but you have to be a full member to access it.  Well worth $30 per year.
Lori
1968 280SL (US)

DavidAPease

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #5 on: June 10, 2023, 03:36:56 »
Assuming that you have an automatic transmission, the subject of this thread might be a starting place:

   https://www.sl113.org/forums/index.php?topic=33479.msg244599#msg244599

          -David
-David Pease
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Cees Klumper

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #6 on: June 10, 2023, 04:12:22 »
I would (indeed) check the functioning of the constant speed solenoid. It may have stopped working or is mis-adjusted.
Cees Klumper
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teahead

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #7 on: June 11, 2023, 21:28:46 »
I would (indeed) check the functioning of the constant speed solenoid. It may have stopped working or is mis-adjusted.

Linkage Tour:  https://www.sl113.org/forums/index.php?topic=5003.0

Many US cars (not sure what the OP has) didn't even have the CSS hooked up (like mine).

However, it DID come w/that dashpot thingy (aka "Vacuum throttle control") that you must remove to do the Linkage Tour adjustment and put back on afterwards.

That dashpot thing raises the idle when you put it in gear.
1970 280SL auto, AC - aka "Edelweiss"

rwmastel

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Re: Motor stalls out when it is hot and you put it in gear
« Reply #8 on: June 13, 2023, 17:30:52 »
What is a linkage tour?
Cole,
It's only been a couple days, but any progress?.
Does the mechanic have your car, or do you have it?
The throttle linkage adjustment process is pretty straight forward to perform.  No special tools or skills required from what I recall, other than patience.
The question about hot and cold idle speeds is a good one to help members understand the state of tune of your car.

Many US cars (not sure what the OP has) didn't even have the CSS hooked up (like mine).
However, it DID come w/that dashpot thingy (aka "Vacuum throttle control") that you must remove to do the Linkage Tour adjustment and put back on afterwards.
That dashpot thing raises the idle when you put it in gear.
I know I haven't been doing much work on my car lately so maybe forgot some terminology.
CSS = constant speed solenoid.  It's engaged electronically when you put your car in gear (or turn on the A/C) and pushes on the throttle linkage to compensate for the load on the engine and avoid stall.  You mention the "dashpot thingy" is vacuum controlled?  What's the real name for what you're referring to here?  Is it the device at the throttle intake butterfly flap?
Rodd

Did you search the forum before asking?
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