Hi Mike. Thanks for taking time to reply in such detail. Yes I have replaced the white rolling bush and the white plastic shackle/spacer that the linkage passes through on the left of the video. Regards Mark
Mike, This was a great Video because I had the same problem and you giving the part number for the plastic grommet I was able to get one. Would you happen to know the location of the driver foot-well vacuum collector reservoir on a 82 280 SL R 107 European model? I believe mine has a leak, because it does not lock the passenger door after engine has been off for a while. Thanks
Thanks for your comment. Ive got a horrible confession to make - I never connected up the central locking vacuum lines on my 1983 SL. I'll have a look and see if I can find it. Mike
Fantastic video. I'm still having issues with play in the throttle on my Dad's 280SL. Does the little bush run inside, touching, the sides of the hockey stick shaped slot all the way through it's travel? My Dad's bush doesn't touch until it gets to the curve, even though I've replaced the bush.
Thanks for your comment. It’s not unusual to have a bit of play in the accelerator pedal. Sometimes the metal of the horseshoe slot has become worn causing a bit of excess play. You can send a short video of the whole mechanism to m_scott65@hotmail.com What part of the country is the car in? Mike
@@MikesMercsandothercars That would be great, thanks. It will be a couple of days until I send it as I'll have to pop across to see my Dad. I'm in Leyland, Lancashire.
@@markhiller8019 Thanks for the video. Yes that is quite a lot of play. Can you remind me - have you already renewed the white plastic cylinder which rolls in that hockey shaped groove? I'll have to pop down to the garage and remind myself of how much play my silver 280SL has. This car is up on a ramp at present and not very accessible. Meanwhile, that microswitch is called the "decl switch" and it basically allows the control unit to distinguish between the idle state and deceleration state when there is no accelerator input. Here is good if not complicated description of its operation "The principle of this system is that when you take your foot off the pedal at speed, high vacuum in the lower intake manifold opens the air valve, allowing air from the air cleaner directly into the lower intake manifold, bypassing the upper intake manifold's fuel sensor plate and throttle. The resulting absence of vacuum in the upper intake manifold makes the fuel sensor plate return to its idle position, cutting off most of the fuel. The unthrottled rush of air into the cylinders also decreases pumping losses. The electrical switch is to ensure the valve only opens during deceleration/overrun, not at idle. If you connect the air valve directly to high manifold vacuum at idle, the engine should die. If it doesn't, the air valve may not be working or some adjustment may be off, or there may be a vacuum leak. You can live without this system, but your fuel consumption will be higher by 20% or more." Mike
No. On a D Jetronic, the only thing the accelerator pedal does effectively is add more air. With the fuel pump running, fuel pressure is constant and the amount of fuel the engine gets, is regulated by the duration and frequency that the injectors fire. That in turn is regulated by the engine vacuum (via the MAP sensor), the trigger points and the engine temp sensor. The ECU takes the data from all those sensors and calculated how long and fast the injectors fire. I am no expert, but you can start to appreciate why a vacuum leak (or faulty MAP sensor) can lead to a running rich condition. The ECU thinks you are adding more air and effectively adds more fuel. Mike
@@MikesMercsandothercars I’m honestly obsessed with this d jet engine. I was reading about it here and there and it’s basically the in between time from mechanical to electrical injection because it has both mechanical analog systems and electronic injection systems. I want to learn everything there is about the djet. I believe it doesn’t run rich because I get pretty good fuel economy.
@@MikesMercsandothercars okay now when I am driving and from a complete stop I push the accelerator pedal down slowly and steady. Not too hard. It kinda of stutters and feels like it’s choking out but it overcomes it as the speed increases.. if the fuel pressure is constant what could it be if not a fuel pressure thing?
Hmmm...if it was me, I would be tempted to monitor the fuel pressure as you were driving to rule this out. I have a Snap On wireless fuel pressure gauge for this purpose but you could also use a standard inline fuel pressure gauge and film it with a Go Pro or iphone in the engine bay whilst driving. Pushing the accelerator adds more air. I guess if you were adding too much air before the ECU is instructed to open the fuel injectors for longer that could cause a lean stalling condition. Have you checked that your MAP sensor is holding vacuum? It could also be stalling out because of an over rich condition which is only cured as you add more air. What have you checked so far? Mike@@joshuaculley9695
I just replaced these on my '85 380 SL (the bushings were inexpensive from ebay). I went to get on the interstate and had no throttle at all. I opened the hood and realized that both were gone. I rigged it back up and limped it home
Авто/Мото
Hi Mike. Thanks for taking time to reply in such detail. Yes I have replaced the white rolling bush and the white plastic shackle/spacer that the linkage passes through on the left of the video.
Regards
Mark
Awesome videos. Right up the alley for all mercedes lovers, but especially the new fans beginning to learn how to work on them. Thank you!
Great video and perfect parts replacement just what i neened
Very well explained. Thank you for taking the time to explain this.
Thanks for you comment - glad the vid was helpful. Mike
Hello sir
Good video.
Where r these parts available , are they available on any websites?
Plz reply.
Thank you
If you are UK based try www.theslshop.com/ in the US Pelican parts.
Mike, This was a great Video because I had the same problem and you giving the part number for the plastic grommet I was able to get one.
Would you happen to know the location of the driver foot-well vacuum collector reservoir on a 82 280 SL R 107 European model?
I believe mine has a leak, because it does not lock the passenger door after engine has been off for a while. Thanks
Thanks for your comment. Ive got a horrible confession to make - I never connected up the central locking vacuum lines on my 1983 SL. I'll have a look and see if I can find it. Mike
the rubber grommet at the bulk is not required as ball fit into the bulk head socket
Fantastic video. I'm still having issues with play in the throttle on my Dad's 280SL. Does the little bush run inside, touching, the sides of the hockey stick shaped slot all the way through it's travel? My Dad's bush doesn't touch until it gets to the curve, even though I've replaced the bush.
Thanks for your comment. It’s not unusual to have a bit of play in the accelerator pedal. Sometimes the metal of the horseshoe slot has become worn causing a bit of excess play. You can send a short video of the whole mechanism to m_scott65@hotmail.com What part of the country is the car in? Mike
@@MikesMercsandothercars That would be great, thanks. It will be a couple of days until I send it as I'll have to pop across to see my Dad. I'm in Leyland, Lancashire.
@@markhiller8019 No probs - when you have sent it just drop me a comment here so I will know to check that email address. Mike
@@MikesMercsandothercars Hi. I've sent a video to your email. Thanks for looking at it.
@@markhiller8019 Thanks for the video. Yes that is quite a lot of play. Can you remind me - have you already renewed the white plastic cylinder which rolls in that hockey shaped groove? I'll have to pop down to the garage and remind myself of how much play my silver 280SL has. This car is up on a ramp at present and not very accessible. Meanwhile, that microswitch is called the "decl switch" and it basically allows the control unit to distinguish between the idle state and deceleration state when there is no accelerator input. Here is good if not complicated description of its operation
"The principle of this system is that when you take your foot off the pedal at speed, high vacuum in the lower intake manifold opens the air valve, allowing air from the air cleaner directly into the lower intake manifold, bypassing the upper intake manifold's fuel sensor plate and throttle. The resulting absence of vacuum in the upper intake manifold makes the fuel sensor plate return to its idle position, cutting off most of the fuel. The unthrottled rush of air into the cylinders also decreases pumping losses. The electrical switch is to ensure the valve only opens during deceleration/overrun, not at idle. If you connect the air valve directly to high manifold vacuum at idle, the engine should die. If it doesn't, the air valve may not be working or some adjustment may be off, or there may be a vacuum leak. You can live without this system, but your fuel consumption will be higher by 20% or more." Mike
Does moving the throttle linkage while the car is not running pump fuel into the engine? Like when you’re testing the linkage for full open.
No. On a D Jetronic, the only thing the accelerator pedal does effectively is add more air.
With the fuel pump running, fuel pressure is constant and the amount of fuel the engine gets, is regulated by the duration and frequency that the injectors fire. That in turn is regulated by the engine vacuum (via the MAP sensor), the trigger points and the engine temp sensor. The ECU takes the data from all those sensors and calculated how long and fast the injectors fire.
I am no expert, but you can start to appreciate why a vacuum leak (or faulty MAP sensor) can lead to a running rich condition. The ECU thinks you are adding more air and effectively adds more fuel.
Mike
@@MikesMercsandothercars I’m honestly obsessed with this d jet engine. I was reading about it here and there and it’s basically the in between time from mechanical to electrical injection because it has both mechanical analog systems and electronic injection systems. I want to learn everything there is about the djet. I believe it doesn’t run rich because I get pretty good fuel economy.
@@MikesMercsandothercars okay now when I am driving and from a complete stop I push the accelerator pedal down slowly and steady. Not too hard. It kinda of stutters and feels like it’s choking out but it overcomes it as the speed increases.. if the fuel pressure is constant what could it be if not a fuel pressure thing?
Hmmm...if it was me, I would be tempted to monitor the fuel pressure as you were driving to rule this out. I have a Snap On wireless fuel pressure gauge for this purpose but you could also use a standard inline fuel pressure gauge and film it with a Go Pro or iphone in the engine bay whilst driving.
Pushing the accelerator adds more air. I guess if you were adding too much air before the ECU is instructed to open the fuel injectors for longer that could cause a lean stalling condition. Have you checked that your MAP sensor is holding vacuum?
It could also be stalling out because of an over rich condition which is only cured as you add more air.
What have you checked so far?
Mike@@joshuaculley9695
I just replaced these on my '85 380 SL (the bushings were inexpensive from ebay). I went to get on the interstate and had no throttle at all. I opened the hood and realized that both were gone. I rigged it back up and limped it home