Late to the party, but you did a great job with this explanation/review of the system. Outstanding! Heading over to part 2 next. Thanks for taking the time to do these videos, they're very helpful! I roll in a 1966 W111 250SEC Coupe, and a 1981 Volkswagen Rabbit Diesel Pickup, so I live in the world of mechanical injection.
One question concerning the controller. When I read the literature in the manual. It says that the knob on the controller only adjusts the fuel mixture at idle. Is this true or does it also control the mixture throughout the rpm range? Thanks Again so much for doing a video series on D-jet. Dave
Hi! I m wintessing some intermitent missfiring on my 4.5 m117 d-jet...the car starts every time with no hesitation...usually when cold runs ok...but sometimes it goes to 2000rpm without doing anything, sometimes starts missfiring even cold,it seems that it s running rich due to strong gas smell coming of the exhaust, but I don t see any sort of smoke.I had the car at a mercedes specialist in London and they looked at distributor spark plugs and it seems their all new.They were not familiar with d jet so I had to drive the car back around 50 miles...the engine pulls really well...but while building up speed it starts missfiring and power dropes for a second or two and then pick s up again.So being intermitent with no smoke coming out the exhaust don t know what to look at...
Hi Pierre. How would I measure that the map sensor is getting the right pressure? I am getting around 12mpg and would like to improve on that if I can. Thanks for the videos. John.
On old jaguars the air flow meter controls the fuel pulses, ...I've notice changing the Mercedes w126 fenders does alot to the cosmetics, ,check all your vacuum on and Mercedez 15 inches and up ☕🔨🙋✈
Hi, I installed a used ECU into my 1975 450sl and it's running rich blowing black smoke.. Do I adjust it from the ECU itself or from the throttle? Thanks
running rich and blowing black smoke....the adjustment is on the ECu but it sounds like the vacuum line to the MAP sensor might be split open, Sam! its standard 7.5mm fuel hose. be prepared to replace it.
@@mercedesclassicswithpierre1753 thank you for your kind help. Hard to find Mechanics for these cars nowadays as most are too old now or have died off. I never felt so old.
It is a good system, but very complicated and would need someone well versed in its workings to carry out repairs, and parts are pricey. Modern full electronic systems are much simpler. Can a D-Jetronic system be upgraded to a modern full electronic system? Are retro kits available for this? Thank you.
I have forgotten the early different series of Bosch fuel injection systems, as they changed over the years with the advancement in computer technology. The system in my 450SEL (W116) performed very well, which I think was D-Jetronic and I liked it, but there finally came a time when it had to be overhauled, and that is where the costs involved weighed in. I did repair it but with parts from a scrap car. I have mentioned complicity, high cost and need for expert know how for these early systems, and another factor is that they are very sensitive to other engine workings like valve gear - timing chain, camshaft, lifters and valve. Plus the efficiency of the ignition system. In other words the D-Jet works very well if the other systems also work well. I recently saw on a British TV show call Car SOS a Triumph Herald being retro fitted from carburretor to fuel injection. If this little British car can be upgraded then I am sure some companies and car clubs in Germany or Europe would have developed a full electronic kit for the D-Jet.
Hello Pierre, I just bought a 1972 Mercedes 280SEL V8 4.5. The out four cylinders are firing properly (Cylinder 1,4,5,8) the middle 4 are not firing where the engine is quite rough and when I take out the plug wires, it does not make any difference on the engine. When I take out the outer 4 cylinder plug wires, the engine slows down. When I switched the fuel injector wires between # 1 and 2 and 5 and 6, the ones that were working stops working and the ones that were not working starts working. So looks like an electric issue. When I put in a test light onto all 8 fuel injector connections, the ground is sold. How ever, the positive light is very low on the outer 4 and the inner 4 cylinders do not have power. I also took out the injector points from the distributor and cleaned them and they looked ok. So is it my ECU? Is there a way to test the ECU? What is your email address so I can send you some pictures.
Hello, +Ali Khan and thank YOU so much for your question(s), we want to answer you as quickly as possible. By signing in our Patreon www.patreon.com/thomaspolk page and making a donation of $10 your are assured of a 24 hour email response from Pierre. If you are already a $10 member please mention along with your question.
@@mercedesclassicswithpierre1753 I have cleaned them thoroughly but still the same. I have purchased the new D-jetroniks computer. It will arrive on Tuesday and I will install it and then let you know.
@@mercedesclassicswithpierre1753 Hello Pierre, So here is what the update is. On my 1972 Mercedes 280SEL, I got a new ECU for it and I fitted it in. Now 6 out of 8 Cylinders are shooting Fuel but Cylinder 2 and 7 are not.I had a Mercedes Mechanic come over to take a look at it. The eletric connection is correct and fine, the timing is OFF. The Fuel pressure is fine, I had taken out the Ignition trigger points before then and cleaned then with Fuel and cleaned them good but that does not mean I did a good job but I can assure yo they are cleaner than before. What could be the issue?
@@AliKhan-ug1ds your injection trigger points are dirty. remove the distributor, remove the trigger point block and clean it. If you need additional info email me at mbownersforlife@bellsouth.net
awesome..please email me at mbownersforlife@bellsouth.net. Expect to have to adjust valves, replace fuel injection hoses, possibly buy an early 3.5/4.5 manual, maybe replace a timing chain, and of course brake work....these are great cars...good luck!
Late to the party, but you did a great job with this explanation/review of the system. Outstanding! Heading over to part 2 next. Thanks for taking the time to do these videos, they're very helpful!
I roll in a 1966 W111 250SEC Coupe, and a 1981 Volkswagen Rabbit Diesel Pickup, so I live in the world of mechanical injection.
WOW!!! You did get my messages thank you so much this means alot!!
Dave
Great presentation on such systems.
I really enjoy your videos, just the right amount of information, keep them coming!
Completely amazing that Benz was that far ahead of the game even at that point in automotive history. My thanks Pierre.
Thanks. Very useful information for me and my 1979 pre he xjs.
Great videos Pierre! They help me a lot. Keep going!
Excellent D-Jet tutorial.
thank you.
One question concerning the controller. When I read the literature in the manual. It says that the knob on the controller only adjusts the fuel mixture at idle. Is this true or does it also control the mixture throughout the rpm range? Thanks Again so much for doing a video series on D-jet.
Dave
it controls idle mixture only. After 1,000 rpm it has little effect and the MAP sensor kicks in.
Hi! I m wintessing some intermitent missfiring on my 4.5 m117 d-jet...the car starts every time with no hesitation...usually when cold runs ok...but sometimes it goes to 2000rpm without doing anything, sometimes starts missfiring even cold,it seems that it s running rich due to strong gas smell coming of the exhaust, but I don t see any sort of smoke.I had the car at a mercedes specialist in London and they looked at distributor spark plugs and it seems their all new.They were not familiar with d jet so I had to drive the car back around 50 miles...the engine pulls really well...but while building up speed it starts missfiring and power dropes for a second or two and then pick s up again.So being intermitent with no smoke coming out the exhaust don t know what to look at...
Hi i experience alot of the problems you described here. Can you contrast this with a distributor type system with mechanical fuel injectors
My 1990 560sec cold start rpm only 600~700 what wrong with car? Please help.
Hi Pierre. How would I measure that the map sensor is getting the right pressure? I am getting around 12mpg and would like to improve on that if I can. Thanks for the videos. John.
On old jaguars the air flow meter controls the fuel pulses, ...I've notice changing the Mercedes w126 fenders does alot to the cosmetics, ,check all your vacuum on and Mercedez 15 inches and up ☕🔨🙋✈
yes, 15 inches and up! that's right!
Hi, I installed a used ECU into my 1975 450sl and it's running rich blowing black smoke.. Do I adjust it from the ECU itself or from the throttle? Thanks
running rich and blowing black smoke....the adjustment is on the ECu but it sounds like the vacuum line to the MAP sensor might be split open, Sam! its standard 7.5mm fuel hose. be prepared to replace it.
@@mercedesclassicswithpierre1753 thank you for your kind help. Hard to find Mechanics for these cars nowadays as most are too old now or have died off. I never felt so old.
good luck. let me know what you find, Sam
Jow can i send a photo of my w116
It is a good system, but very complicated and would need someone well versed in its workings to carry out repairs, and parts are pricey. Modern full electronic systems are much simpler.
Can a D-Jetronic system be upgraded to a modern full electronic system? Are retro kits available for this? Thank you.
no...but honestly, I have very few issues with d-jet. It has been consistently reliable and repairable, unlike what most people think.
I have forgotten the early different series of Bosch fuel injection systems, as they changed over the years with the advancement in computer technology. The system in my 450SEL (W116) performed very well, which I think was D-Jetronic and I liked it, but there finally came a time when it had to be overhauled, and that is where the costs involved weighed in. I did repair it but with parts from a scrap car.
I have mentioned complicity, high cost and need for expert know how for these early systems, and another factor is that they are very sensitive to other engine workings like valve gear - timing chain, camshaft, lifters and valve. Plus the efficiency of the ignition system. In other words the D-Jet works very well if the other systems also work well.
I recently saw on a British TV show call Car SOS a Triumph Herald being retro fitted from carburretor to fuel injection. If this little British car can be upgraded then I am sure some companies and car clubs in Germany or Europe would have developed a full electronic kit for the D-Jet.
Wow, not that many views.
I guess most people catipulate at this point and let their mechanic fix the issue.
Nice intro into D-jetronic.
you're welcome! I wish I could have gotten Gael to do the into though.
Hello Pierre, I just bought a 1972 Mercedes 280SEL V8 4.5. The out four cylinders are firing properly (Cylinder 1,4,5,8) the middle 4 are not firing where the engine is quite rough and when I take out the plug wires, it does not make any difference on the engine. When I take out the outer 4 cylinder plug wires, the engine slows down. When I switched the fuel injector wires between # 1 and 2 and 5 and 6, the ones that were working stops working and the ones that were not working starts working. So looks like an electric issue. When I put in a test light onto all 8 fuel injector connections, the ground is sold. How ever, the positive light is very low on the outer 4 and the inner 4 cylinders do not have power. I also took out the injector points from the distributor and cleaned them and they looked ok. So is it my ECU? Is there a way to test the ECU? What is your email address so I can send you some pictures.
Hello, +Ali Khan and thank YOU so much for your question(s), we want to answer you as quickly as possible.
By signing in our Patreon www.patreon.com/thomaspolk page and making a donation of $10 your are assured of a 24 hour email response from Pierre.
If you are already a $10 member please mention along with your question.
Ali. you have dirty injector trigger points. remove the distributor and you will find them in there...clean them thoroughly with brake parts cleaner
@@mercedesclassicswithpierre1753 I have cleaned them thoroughly but still the same. I have purchased the new D-jetroniks computer. It will arrive on Tuesday and I will install it and then let you know.
@@mercedesclassicswithpierre1753
Hello Pierre,
So here is what the update is. On my 1972 Mercedes 280SEL, I got a new ECU for it and I fitted it in. Now 6 out of 8 Cylinders are shooting Fuel but Cylinder 2 and 7 are not.I had a Mercedes Mechanic come over to take a look at it. The eletric connection is correct and fine, the timing is OFF. The Fuel pressure is fine, I had taken out the Ignition trigger points before then and cleaned then with Fuel and cleaned them good but that does not mean I did a good job but I can assure yo they are cleaner than before.
What could be the issue?
@@AliKhan-ug1ds your injection trigger points are dirty. remove the distributor, remove the trigger point block and clean it. If you need additional info email me at mbownersforlife@bellsouth.net
I need some advice, I'm getting ready to buy a 1973 450SE for $350-$500 and I wanna know What to expect when im getting into this car
awesome..please email me at mbownersforlife@bellsouth.net. Expect to have to adjust valves, replace fuel injection hoses, possibly buy an early 3.5/4.5 manual, maybe replace a timing chain, and of course brake work....these are great cars...good luck!
more on w108s! ;) . on mine there is a m110 engine fuel injected (with the ''flapper intake''')does that one have a computer also?
What year was the m110 engine from? 1972-76 was d-jet, after that in 1977 they switch to computerless k-jet.
i not sure ,i have posted on your video on google + a picture of the unit,any luck with the video we discussed for the greasing points on the w108 ;)
I tell you, the injectors work with 3 volts ! Not more .
Do you install mega squirt?
mega squirt is junk. I keep whatever fuel system came on the car, and make it work right. that;s the pierre hedary way.