Problems with fuel injector installation on a 560SEL

[cmaxwell]

Hey everyone,

OK, so I knew that my car (a 91 560SEL) needed new fuel injector seals and o-rings, so I got all my stuff together with some great instructions and started the job.

The first 3 injectors came out fine, but the last one not so good. The hex nut that hold the bracked on top of the injector stripped itself. This is that 5mm hex nut inside the clip bracket on top of the injector. It's the last one on the passenger's side, closest to the firewall, so its the hardest to get to. Very frustrating. Anyone have any ideas on how to get that bad boy out?

Also, I noticed that one of the injectors is not the correct injector for my car. I know I need to get the right one, but I'm wondering what kind of symptoms that would cause. I originally took this project on because the car misses. Sometimes dramatically, other times hardly noticeable. My mechanic (who is aware of and totally in support of my DIY mentality for certain projects) was the one who said I needed new seals and holders. From the gunk around a couple of the injector holders, I tend to believe him when he said they are leaking.

I wasn't planning on replacing the injectors because the mechanic and the dealer told me that the car shouldn't need new injectors at 114k. I'm kind of lost on what to do here. Is it worth just spending the extra $400 bucks on the injectors? Should I just take my 7 of 8 injectors somewhere and have them tested? If so, where do you take them?

As always, thanks for being out there, and thanks for any information you can provide.

Craig