SL/R129: New ignition switch but no start! R129 300
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Newbie
Joined: Jun 2023
Posts: 4
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From: California
1992 300sl MB
New ignition switch but no start! R129 300
Hello all; I’d like to introduce myself and my 1992 300SL to the forum. I previously traded my 1990 W124 for my current R129, and knew I would run into a few issues trying to get it back on the road. The main issue which will receive attention last is the torque converter replacement(previous owner could not shift into gears; started off with no reverse then eventually the rest of PRNDL). I already purchesed the part but decided to put it off until I can get the car to kick over.
Long story short the car did need a new ignition switch as the previous owner broke the key. I’ve already installed the new switch, charged and tested the battery, replaced the valve cover gasket and O rings as the spark plug happened to have some oil on them- But still the car won’t kick over.
Im starting to think I might be running into some sort of security issue with the new ignition switch as it is definitely not OEM. I’ll add a video below of me attempting to start the car after I replaced the valve gasket and o rings on the spark plugs (PS spark plugs are like new)
Long story short the car did need a new ignition switch as the previous owner broke the key. I’ve already installed the new switch, charged and tested the battery, replaced the valve cover gasket and O rings as the spark plug happened to have some oil on them- But still the car won’t kick over.
Im starting to think I might be running into some sort of security issue with the new ignition switch as it is definitely not OEM. I’ll add a video below of me attempting to start the car after I replaced the valve gasket and o rings on the spark plugs (PS spark plugs are like new)
Thread Starter
Newbie
Joined: Jun 2023
Posts: 4
Likes: 0
From: California
1992 300sl MB
Update 1:
I went ahead and thouroughly cleaned the spark plugs and the inside of the valve where they go in. I decided to trouble shoot the spark plugs (which are new) by taking the first plug out to test for a spark- and what do you know there was no spark at all! This leads me to believe it could be the distributor itself as this same issue happened on my W124 with no starting and healthy crank. Any suggestions would be appreciated.
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Joined: Mar 2016
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From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
If this is an M103 engine make sure the center HV pin spring in the distributor is not broken. That is the achilles heel of replacement caps.
When you take off the cap the pin may just fall off.
When you take off the cap the pin may just fall off.
Thread Starter
Newbie
Joined: Jun 2023
Posts: 4
Likes: 0
From: California
1992 300sl MB
I was able to successfully replace the hub and wires and what do ya know, it just so happened to be the issue on my car starting. Next up I’m removing the torque converter but I’ll probably make a new forum for transmission removals. Thanks for the reply!
