I allways enjoy your videos, because you allways want to understand the reasons and how the technique works. Now you identified nicely the vapour lock, ethanol, way of pressuire control, role of filters details! Thank you for all your efforts! In this video just the smiling kids were missing in the back seat...
Hello, Normally the pumps as in the video should be lower than the tank, the priming is done by gravity. In your video but also on other sites the pump is fixed on the floor of the trunk higher than the tank. Did you have trouble starting the circuit by default of priming? How does the pump behave after a certain time of vehicle inactivity? or even depending on the level of fuel in the tank?
Of course you did check the fuel filter right by the injection pump or directly under I shall say. Just wondering if you noticed difference in the pressure and flow with the new filter? I noticed that ethanol tends to go jelly and creates restriction when I let the fuel sit for long time.
Hard to say because I change the fuel filter every few years. Also I changed it when I got the car and rebuilt motor originally 11 years ago. So I had no difference because my fuel filter was clean to begin with
If you're talking about the mechanical fuel pump. It's been a while but there is a little cut out on the gear that lines up with something, I can't remember
Question: my 108 280se starts a little bit difficult because the injection solenoid works just for 1 second. (Test lamp) How can I get a longer injection time while starting? BTW the second start time runs IMMEDIATELY.
Pull the injector out and see the spray pattern on it, lots of times they get clogged causing difficult starts. I clean mine with compressed air and now it shoots perfect. Another thing you can do you can just disconnect the wire from it and hook up 12 V to it with a button next to your steering wheel on a dashboard. That's what I did I just press it when I need it.
First thing you should have done is take that fuel pump out & throw it away!! Next, change the pressure regulator. Do not use ethanol blend fuel in these cars, ever. They run like crap, & the injection pumps are not designed for ethanol blend fuels. They need 95 octane gasoline only, nothing else. Want to use a good fuel pump? Get one for a twin cam 280SE. Only use BOSCH fuel pumps in these cars. If you have the original pump, even better.
The pressure regulator is fine, those never break, in Canada you can't buy ethanol free fuel, and the highest they sell here is 91 octane. Which is fine because it's only 9:1 compression ratio. 91 is all you need, also I have stepped pistons installed which allows me to run 87 octane. Trust me I know everything about these cars. Thanks for the input though
@@ProblemSolverGarage I used to fix these old Mercs for my professional work. As for the fuel, not being able to use 100% petroleum is not good. Yes, those pressure regulators can break. I've replaced hundreds of them. I've come across people like you before, with the I know everything about these cars type attitude when dealing with others like me. Modifying the engine to run low octane fuel is not wise with those engines, & it will cost you in the long run, because you lost the power advantage by doing this. From factory with Euro spec, they were a fast car, with a fair amount of power. You're running ethanol blend fuel, so you should modify the filtration system by installing a filter that has a water trap in the bottom.
The stepped pistons were the only option, nobody had oversize pistons for sale so I had no choice and I got ones from Britain designed to run an 87 octane. Good idea about the filter might look into that, thanks for all your input.
@@ProblemSolverGarage Mahle is the company you go to for oversized pistons. They are the manufacturer of the original pistons. Another thing you may want to do, unless you've done this already, is go through the transmission. Those are a 4 speed, yet a lot of people think they are only a 3 speed. One thing that might surprise you is that car can be tow, or roll started. The transmission has two pumps. One is engine driven, the other output shaft driven. If you cannot tow or roll start the car, the transmission has an internal fault, or is low on fluid.
@@christophermarshall5765 OK thanks for the input. The Pistons were on back order 11 years ago when I was rebuilding the engine so I worked with what I was able to get, I literally bought the last set in the world at the time. Car still runs good 11 years later though.
Good job! Many times people do not know that the original pump is repairable, both the short and the long one.
I allways enjoy your videos, because you allways want to understand the reasons and how the technique works.
Now you identified nicely the vapour lock, ethanol, way of pressuire control, role of filters details!
Thank you for all your efforts!
In this video just the smiling kids were missing in the back seat...
Thank you
Thank you, I always appreciate your W108 videos!
Glad you like them!
Nice job. We had one of these in the early 80s. Was a great car.
This guy is brilliant, thanks big time from UK.
Very welcome
Thank you very much
Hello, Normally the pumps as in the video should be lower than the tank, the priming is done by gravity. In your video but also on other sites the pump is fixed on the floor of the trunk higher than the tank.
Did you have trouble starting the circuit by default of priming? How does the pump behave after a certain time of vehicle inactivity? or even depending on the level of fuel in the tank?
very good video as usual. Is the new fuel pump noisy ?
Not really can't hear it when the car is running
Of course you did check the fuel filter right by the injection pump or directly under I shall say. Just wondering if you noticed difference in the pressure and flow with the new filter? I noticed that ethanol tends to go jelly and creates restriction when I let the fuel sit for long time.
Hard to say because I change the fuel filter every few years.
Also I changed it when I got the car and rebuilt motor originally 11 years ago.
So I had no difference because my fuel filter was clean to begin with
Greetings What is the timing for the fuel pump TDC?
If you're talking about the mechanical fuel pump. It's been a while but there is a little cut out on the gear that lines up with something, I can't remember
Question: my 108 280se starts a little bit difficult because the injection solenoid works just for 1 second. (Test lamp)
How can I get a longer injection time while starting?
BTW the second start time runs IMMEDIATELY.
Pull the injector out and see the spray pattern on it, lots of times they get clogged causing difficult starts. I clean mine with compressed air and now it shoots perfect.
Another thing you can do you can just disconnect the wire from it and hook up 12 V to it with a button next to your steering wheel on a dashboard. That's what I did I just press it when I need it.
@ the injector sprays ok but I think is too short time (1 second).
Is it possible to get a longer spray time?
Just curious, what kind of fuel mileage you get out of it? Litres per 100km. I got a 71 going but never really finished it up.
19 L for 100 km
It's a fast car, one of the fastest ones in 1969
Sorry 19 mpg
Not too sure about kilometers, basically same as my minivan maybe like 14 L to 16 L for 100 km
Greetings What is the timing for the fuel pump TDC?
@ It’s the other way around! Engine timing for the fuel pump preset. 20deg. ATDC. Make sure you are on the power stroke.
First thing you should have done is take that fuel pump out & throw it away!! Next, change the pressure regulator. Do not use ethanol blend fuel in these cars, ever. They run like crap, & the injection pumps are not designed for ethanol blend fuels. They need 95 octane gasoline only, nothing else. Want to use a good fuel pump? Get one for a twin cam 280SE. Only use BOSCH fuel pumps in these cars. If you have the original pump, even better.
The pressure regulator is fine, those never break, in Canada you can't buy ethanol free fuel, and the highest they sell here is 91 octane. Which is fine because it's only 9:1 compression ratio.
91 is all you need, also I have stepped pistons installed which allows me to run 87 octane.
Trust me I know everything about these cars.
Thanks for the input though
@@ProblemSolverGarage I used to fix these old Mercs for my professional work. As for the fuel, not being able to use 100% petroleum is not good. Yes, those pressure regulators can break. I've replaced hundreds of them. I've come across people like you before, with the I know everything about these cars type attitude when dealing with others like me. Modifying the engine to run low octane fuel is not wise with those engines, & it will cost you in the long run, because you lost the power advantage by doing this. From factory with Euro spec, they were a fast car, with a fair amount of power. You're running ethanol blend fuel, so you should modify the filtration system by installing a filter that has a water trap in the bottom.
The stepped pistons were the only option, nobody had oversize pistons for sale so I had no choice and I got ones from Britain designed to run an 87 octane.
Good idea about the filter might look into that, thanks for all your input.
@@ProblemSolverGarage Mahle is the company you go to for oversized pistons. They are the manufacturer of the original pistons. Another thing you may want to do, unless you've done this already, is go through the transmission. Those are a 4 speed, yet a lot of people think they are only a 3 speed. One thing that might surprise you is that car can be tow, or roll started. The transmission has two pumps. One is engine driven, the other output shaft driven. If you cannot tow or roll start the car, the transmission has an internal fault, or is low on fluid.
@@christophermarshall5765 OK thanks for the input. The Pistons were on back order 11 years ago when I was rebuilding the engine so I worked with what I was able to get, I literally bought the last set in the world at the time. Car still runs good 11 years later though.