I want to replace the fuel injectors on my 1995 e320 Cabriolet, but I can't figure out how to remove the rail. It appears to be bolted onto the engine block and sandwiches the intake manifold. I can't figure out how to get to that last bolt near the firewall. Is there a trick to this? Also, I assume I have to remove the rail before I can remove the black plastic cover that is on top of the fuel rail.

The plastic cover at the center of rail unsnaps from bottom , lightly pull black cover outwards and up from the bottom ,then pivot 180 degrees straight up, then remove bolts to rail 5 bolts i think allen 6mm,you may need 1/4 universal with 6mm allen socket or 6mm ball allen

hello derohanes, and merry christmas

if i remember correctly fuel injector removal goes as follows:

1 depressurize the fuel system by removing fuel pump relay and then cranking the engine. then you can loosen the fuel lines from the rail, just make sure to mark them so you dont mix them up when reassembling.

2 remove the black air intake crossover pipe

3 "Also, I assume I have to remove the rail before I can remove the black plastic cover that is on top of the fuel rail. "

the cover comes off before the fuel rail does. pry off the black cover of the fuel injector wiring harness, and in the vicinity of the fuel pressure regulator you will find a bolt(10mm or 8mm ) EDIT: and there is another 10mm bolt near the firewall, holding down the remainder of the black plastic , after removing the bolts you will be able to move the black plastic channel out of the way.

4 as nulu mentioned earlier, the fuel rail is held in place by 5 allen head bolts. two near the thermostat housing, one in the middle and two near the firewall . the removal of these bolts is a major pain in the but. i use a combination of tools to get the job done. an allen socket in conjunction with a flexi-head socket extension along with a few different sized extensions will be very useful for the job.

as for the bolts near the fire wall, i use a modified allen wrench which i have sawed off and bent a little bit, and i use a small 10 inch pipe as a breaker bar . removing the oil filter cap may help create some more space as well.

5 after the 5bolts are removed, just grab the fuel rail by each end an pull up , the fuel rail should come out.

6. each fuel injector is held to the fuel rail by a little metal clip, which you slide off to remove.

as far as the injectors go, you may not need to replace them. have a reputable shop flow test them for you, before you shell out 600 dollars for new ones.

i had a rough startup issue , i pulled my injectors an took them to be tested, found out that my injectors were working properly(proper spray pattern) but when the injectors were pressurized and off, one of them leaked a bit. so,i replaced it and all is well now.

what kind of issues/problems are you having with your M104 that you suspect the injectors?

Timmyr,
Thanks for the step by step...very helpful. To answer your question, I get some missing at idle once the engine is warmed up. You are right About testing before replacing. I understand Witch Hunter is a good resource. I do have one question. Once I get the fuel rail unbolted, you mentioned to pull the fuel rail up. I know about the clips that you are referring to, but I'm not sure if that is all that is holding fuel rail to the injectors. Do I need to remove the clips and electrical connections before pulling the fuel rail up?

hey derohanes,

1 i'm not sure 100% sure what could be caausing your missfire at warm idle, but for starters, i would suggest you keep it simple. i'm pretty sure that everyone on this forum will suggest that the first thing you should do is read/pull the codes. use the search option for more info, search for "w124 diagnostic trouble codes" and "blink code reader"(all the parts can be obtained at radio shack). then go from there .

2 as for witch hunter, i have not had any experience with them or their services, ask around, maybe someone from the peachparts forum knows of a good shop.

3 once all five of the fuel rail bolts are removed, disconnect the electrical plugs which go to each injector ,but leave the metal clips at the top of each injector on until you have pulled the entire fuel rail along with injectors from the intake manifold. the only thing keeping the fuel rail in the black plastic intake manifold are the fuel injector O-rings, so just pull up on each end of the fuel rail, and you'll eventually get it along with the injectors out of the plastic intake manifold.

then....

4 you can remove the metal clips which keep the fuel injectors on the fuel rail, all you have to do is pull on the injector to get it out of the fuel rail, the only thing keeping it in the fuel rail is a rubber O-ring, they are on there pretty tight though, so just twist and pull til you get em out.

ps. but before going to all this trouble, i would once again suggest that you pull the codes first

good luck