Are w124 injectors DIY'able? - Page 2 - PeachParts Mercedes-Benz Forum

ps2cho · #16 02-09-2009, 03:43 AM

Quote:

Originally Posted by glenmore

When I changed mine out, I could have reused the old insulators. There was no damage or wear in the plastic other than being discolored. IIRC there is an "O" ring there that should be renewed.

glenmore
1991 300CE
2000 C280

That's what I figured as all I hear is that the O rings can go bad and cause vacuum leaks. I'll pull the insulators and if they look okay I'll reuse them...if I am suspect on any of them for any reason I'll replace them.

Thanks for all the info guys!

Bob Weir · #17 02-09-2009, 10:27 PM

Quote:

Originally Posted by deanyel

You wouldn't want to send out CIS injectors to be cleaned and rebuilt - it's just too cheap to replace them.

My miscue. I priced injectors for my 94 e320. $85 ea for m104 vs $29 ea for m103.

ps2cho · #18 03-21-2009, 02:53 PM

I have read that many injectors never pass flow tests even when new...should I get mine cleaned and flow tested rather than buying new? What would you guys recommend.

The injectors are pretty much the only thing left that could be causing my misfires. I've been through everything else. Am I right in reading that if one injector is opening early, the pressures on the rest of the injectors are thrown off due to the CIS' design?

tilac1 · #19 03-21-2009, 03:15 PM

I think I've got the same problem. I took out #1 injector only to look at (not wet/leaking) but I replaced the small rubber seal with a new one. The insulators are plastic. No need to replace but note the orientation of them (there's a hole through the middle). I've got the stumble at restart too. My idle is also not smooth so I'm thinking a bad spray pattern. I've been reluctant to replace them because of less than 50k miles and with other CIS-E cars never needed to, even after 100k+ miles. Oh well. Maybe I'm lean at idle but without an exhaust gas analyzer I've no way to know. Runs great otherwise so I've 'lived with it.'

deanyel · #20 03-21-2009, 08:32 PM

I don't think anyone refurbishes CIS injectors - cost with freight would be about the same as buying new ones.

ps2cho · #21 03-22-2009, 01:07 AM

Quote:

Originally Posted by tilac1

I think I've got the same problem. I took out #1 injector only to look at (not wet/leaking) but I replaced the small rubber seal with a new one. The insulators are plastic. No need to replace but note the orientation of them (there's a hole through the middle). I've got the stumble at restart too. My idle is also not smooth so I'm thinking a bad spray pattern. I've been reluctant to replace them because of less than 50k miles and with other CIS-E cars never needed to, even after 100k+ miles. Oh well. Maybe I'm lean at idle but without an exhaust gas analyzer I've no way to know. Runs great otherwise so I've 'lived with it.'

Right...same here. I've driven the 300TE every day for the last 4 years with the problem...It doesn't effect its ability to drive...only the idle quality at the lights.

Quote:

Originally Posted by deanyel

I don't think anyone refurbishes CIS injectors - cost with freight would be about the same as buying new ones.

Fair enough. With new insulators and seals included total is $178 from ********arizona. Not too bad. Glad the K-Jet are so cheap compared to other x-jet systems. Gonna replace the insulators for good measure...last thing I would want is to skimp on $25 and have the problem revolve around leaking insulators...

John5788 · #22 03-22-2009, 03:15 AM

i just replaced all of the injectors, injector seals, insulators and o-rings today on my m103. cylinders 3 and 4 were the most difficult, but the job was pretty easy.

car seems to drive alot nicer now

ps2cho · #23 03-22-2009, 01:04 PM

Any tips for accessing 3 + 4?

ps2cho · #24 03-26-2009, 01:00 AM

Got done. Injectors were my rough idle misfire problem!
Took about 1hr 30mins to do it....very straightforward.

It seems I did not need the lower bushing that I purchased....Guess ********az was wrong. Oh well only out a couple bucks.

tilac1 · #25 03-26-2009, 07:15 AM

Great news. Congrats. How many were leaking or clogged at idle? Your MPG should be ~20 now. I'm gonna bite the bullet and do this job also.

ps2cho · #26 03-26-2009, 12:16 PM

Quote:

Originally Posted by tilac1

Great news. Congrats. How many were leaking or clogged at idle? Your MPG should be ~20 now. I'm gonna bite the bullet and do this job also.

Not sure...it was getting dark outside so decided to just do them all at once. The insulators looked very tarnished...so I am glad I bought new ones.

Filled the car up yesterday so fingers crossed I'll be spending less at the pump.

pawoSD · #27 03-26-2009, 12:40 PM

Awesome, that's great to hear! Looks like I'll be pestering the wife again to let me change them out on her 300E....it has an occasional rough idle and has been cranky about re-starting (will die unless you give it a shot of gas with the pedal when starting), but once started it runs fine and never stalls. I suspect the injectors are leaky/not atomizing correctly. At 137k and original I bet they are more than due for replacement (as well as the insulators and o-rings)

ps2cho · #28 03-26-2009, 12:51 PM

Yes I recommend spending the extra $20 and getting the insulators.

Mine is only 93k miles and "supposedly" changed just before 60k miles...which now I am doubting.