[98mkiv]

So I had an rough idle start up on me one day on deceleration. Was intermittent but then became stable and threw the P0306 code.

So I ordered a used injector off of ebay for $200. Took 3 days to arrive.

I dug into the motor to have the injector removed so when the new used one arrived I could just drop it in. Here are the steps in case you care to know.

Remove:
engine cover/oil fill cap
strut braces
battery cable that runs across motor
cabin air filter
fascia under the cabin air filter
booties and plate the strut braces pass thru
rear engine cover
EGR crossover hose clamp v-band
both connectors on the intake manifold forward
both connectors on the intake manifold rear (top and bottom)
the M10 bolts on the intake
the M11 nuts on the intake (yes, an actual M11, WTF BMW?!)
intake pipe from throttle body - remove the wireform so you can pull it off easily and it will stay out of your way
lift off the manifold, watch for the orange rubber gaskets and spacer retainers, they like to fall out and then you need to go find them which means dropping the belly pan. Same goes for all the hardware. Have a magnet on an extension ready as well as a flashlight.
Manifold pops off and you're into the injectors

with an 17mm wrench remove the injecotor feed line
remove the injector return gently pry up the white plastic, then pull up on the return line
remove the two M8 nuts on the injector retainer plate

so this is where I got to when I figured out that this beastly injector wasnt coming out. It's an M14 thread and since I could not find ANY injector removal tool, I when to the store and bought a standard $1 M14 lug nut. I welded it to the end of my slide hammer adaptor. I had to cut the stud off the adaptor to weld the nut to it, but you can probably imagine what this looks like. Having this coupling between the injector and the slide hammer is the key here.

remove the two suspa struts off the hood and have someone hold it vertically while you thread the adaptor and slide hammer to the injector (only needed if you're doing #4 , 5 or 6.

A few hits with a 10# slide hammer and it popped out. Be sure you cover all the open intake ports as this will create a mess you don't want going down those holes.

Injector comes out, but the hole was full of shit. Using compressed air I blew all this out, then had to use a dental pick to get the crap stuck at the bottom out. Also had to retrieve the copper ring from the bad injector. This is key too.

That's it. Installation is the reverse and quite easy. Whole process took me less than 2 hours excluding trying to figure out how to make a tool to pull the old injector out. No tool? You WONT GET IT OUT. This sucker was welded in there by corrosion. See the pic of the old injector. I was like, WTF is this thing? Was this a marine engine at some point????

when I put it all together it took 30 seconds of cranking to start as the FP needs to build pressure. Then it ran like shit and would not clear out after a 5 minute drive which really bummed me out. I cleared the codes with my phone and a $5 ELM BT scanner, restarted, and CEL went away and it's been fine since.

There is a code on the injector but this might be for microtuning, which I don't give a damn about. It runs like a raped ape and I'm still happy with it. Saved myself $2800 (that was the stealership quote) and got off with $200 for the injector, my time and of course $1 lugnut and $0.30 worth of MIG wire. My car has 135K miles on it and I it's a great driver.

Anyway, hope this helps.

Cheers

[98mkiv]

Here are the pics of the old injector. Note the corrosion south of the o-ring. That's not oil gunk, that is missing metal from corrosion.

[32valves]

you had that dreadful miss at idle too?

[32valves]

Originally Posted by 98mkiv

Here are the pics of the old injector. Note the corrosion south of the o-ring. That's not oil gunk, that is missing metal from corrosion.

can send me a picture of your contraption, cause I need to replace #4 injector....

[DozerDan82]

Here is how I removed mine, just used what I had on hand. I made certain to favor the injector threads, since it was only a nut that was connecting them, not ideal, but none of mine looked that bad. A few taps and they all popped out.


Mine is a bolt, nut and a random F250 camber bushing I had in the tool box. Worked just fine.

I also found, and would recommend that you spray where they go in with some penetrating oil, as it will lube up the o-ring and let it come out. Also clean as much of the area around the injector as you can to keep junk from falling in.

[32valves]

Originally Posted by DozerDan82

Here is how I removed mine, just used what I had on hand. I made certain to favor the injector threads, since it was only a nut that was connecting them, not ideal, but none of mine looked that bad. A few taps and they all popped out.


Mine is a bolt, nut and a random F250 camber bushing I had in the tool box. Worked just fine.

I also found, and would recommend that you spray where they go in with some penetrating oil, as it will lube up the o-ring and let it come out. Also clean as much of the area around the injector as you can to keep junk from falling in.

so you using the bolt and bushing like a slide hammer?

[335dlci]

The injector needs to be calibrated to the DDE after replacement via ista or anything like it.

[SoZoX]

I looked at the replacement guide in ista when my father in laws 335i had bad injector. Man was that a process just to replace the one. Special tools needed to slide the seals on etc etc. At some point the guide advised that injector tip should not be exposed to outside elements more than 20 min or so. What was that about? It also came with protective cap that should be removed 20 min before etc etc. I do not get it that you just can get an old injector off ebay and pop it in... hmmm... I believe INPA could do the calibration also.

[DozerDan82]

Originally Posted by 32valves

so you using the bolt and bushing like a slide hammer?

Exactly!

[98mkiv]

My injector, as you can see from the pics, was really corroded and in there solidly. I had to use a heavy slide hammer to get it free with a lot of force. It did come out, bit by bit though......

[Mark M]

Could the visible corrosion / wear be a result of the force used to remove it and not necessarily the environment it lives in?

[32valves]

my injector from last week with 77k on it.

[DozerDan82]

Originally Posted by 32valves

my injector from last week with 77k on it.

Wow that is rough. Mine has 105k ish on it and mine were not that bad at all. They all popped out with my little 'slide hammer' set up.