So, tackled the fuel injector replacement today...first, let me say that it was ridiculously easy. I tend to "overthink" my projects before doing them, and this was no exception - but it was uncessary.
I will also say that it was worth it's weight in gold - quieted the engine right down. Not that it was deafening or anything prior, but I was just starting to get a slight "hammering" on the engine as is notorious for tired injectors. After replacement noticed an immediate sound reduction at idle, and also at highway speed (and everywhere in between). I can hear the boost kick in clear as day on the highway now, whereas before it was getting overshadowed by the engine noise. I honestly can't believe it...money well spent. Looking forward to seeing what this does to my fuel economy, which was down to 22-23mpg (though not bad for a 110 with terrible aerodynamics and 235/85-16 KM2s).
So here's a play-by-play best as I can recall, with PICTURES BELOW matching up to each numbered step:
1) Remove the hood - just helps to make more room under the hood for working.
2) Before getting started, CLEAN the engine around the injectors thoroughly...you don't want any gunk/etc falling down into the injector holes once you remove everything. I had recently degreased my engine so it wasn't too bad, but hit it with Brakleen anyhow to get any residue off.
3) Crack the FUEL SPILL RAIL bolts (I think they were 12mm), but be gentle - you don't want to snap/strip these, and they shouldn't be on there too hard anyhow. Start with one and work your way down as you'll be moving the entire rail out of the way.
4) Move the spill rail out of the way once all the bolts are undone.
5) There is a bracket/plate that holds each of the injectors in place, and each plate is held down by a nut fastened to a stud. Undo each of these and remove the nut (NOTE FOR LATER: when putting these back ON, be careful not to over-torque them...I cracked one of the studs on reassembly - but it was a quick trip to the hardware store for a replacement but could have been avoided).
6) Once each nut is removed on the bracket/plate, move to the fuel pipe connection at the top of the injector. Likewise, crack each one first - being gentle - and then remove each pipe from the injector. Be careful just to gently move them to the side, keeping in mind that the pipe goes directly to the fuel pump and is a hard line so you want to make sure not to bend/kink these. But moving them out of the way will allow you enough room to work for injector removal.
7) Pic of the injector once everything is disconnected.
8) The next step is to see if the injector is "stuck" to the block, or if it moves freely and *hopefully* will come out. I put a 15mm wrench on the injector and gently wiggled everything back and forth to check for movement and ensure that the injector would come free easily. I lucked out, each injector moved back and forth without a problem - though from my preliminary reading "stuck" injectors can certainly be an issue. Other options if this happens are: a) affix a slide hammer to the threaded end of the injector and remove...this is the preferred method, or b) once the injector is unhooked you can use the engine "compression" by turning it over to shoot the injector out...BUT this is not recommended, can be dangerous, and if undertaken one must put a heavy blanket/etc over each injector to absorb the injector as it shoots out - again NOT recommended and I take no responsibility for issues with this.
9) Once each injector was unhooked and I verified that each was wiggling and looked loose enough to remove without issue, I simply put a pair of vice grips on each to get some upward leverage and wiggled it up and out. During this motion, the bracket/plate that holds each injector in place will also work it's way up and eventually you'll be able to slip this plate free once it clears the mounting stud that each holding nut affixes to (but you'll recall we had previously removed each nut from the studs).
10) Pic of the plate/bracket that holds the injector in place coming free.
11) If you're lucky - like I was - your injector will pull free and come right out as shown here.
12) Make sure the injector has the copper washer on the end of it, you don't want this to accidentally be stuck down in the injector hole on the block otherwise you'll have a leaky injector gauranteed.
13) Get your new injector out and ready to go in.
14) Slip a new copper washer on the injector...you DEFINITELY want to put on new washers, do NOT recycle the old ones or they may be prone to leak, causing you more headaches than the $0.50 for each new washer.
15) I used a dab of grease on the copper washer before putting it on the injector in order to help it stay put while I inserted it back into the injector port in the block - keep in mind you're turning this upside down so you don't want the copper washer to slip off and fall into the injector hole since fishing it back out would be a pain in the arse, so the grease is just helping to fight gravity and keep it stuck to the injector.
16) Speaking of copper washers, each bolt on the fuel spill rail (taken off in step 3) has two copper washers on each bolt, one on the outside and one on the inside as shown here. Make sure to likewise replace each of these washers as well.
THAT'S IT! Essentially, reverse the steps slipping the new injector into each port, hook everything back up, snug up all bolts/etc, and you're all set. While you're in there, you may want to inspect the fuel spill rail rubber tubing (with the cloth sleeve) to make sure it is in good shape. Mine looked fine, and I opted not to replace it...though to be cautious I probably should have and will in the near future - but this can be replaced without taking anthying apart so it can be done at any time.
WORD OF CAUTION #1: as I mentioned above on #5, when torquing the injector bracket/plate that holds the injector in place, these slip over a stud that protrudes from the block. There is a nut that then fits on the stud and you tighten up to keep things in place. I over-torqued mine and broke it right off...so I had to hit the hardware store for a replacement (which I think was just a standard automotive M8 stud that worked just fine). The LAST TWO PICS show the broken stud and the hole where the stud screws into the block. This probably applies to all of the above steps, take it easy and don't feel the need to "Hercules" anything like I did.
WORD OF CAUTION #2: on first test drive, I noticed one of my injectors was leaking. Took it home, popped the injector out, and there was a lot of crud that must have fallen in the hole when I removed the injector...it was caked to the copper washer and was preventing it from making a good seal. I cleaned everything off, reassembled, and it didn't leak a drop after that.
All-in-all, if I hadn't broken the stud I probably would have been done with this in less than an hour from start to finish. Honestly, it was unbelievably easy and straightforward - and again I notice positive results from the new injectors right away. I highly recommend it for anyone that is in the 70k-80k mileage range like I was.
If there's anything I missed or something that people would like to add, feel free - just figured this may help others that are contemplating an injector change in the near future.
I will also say that it was worth it's weight in gold - quieted the engine right down. Not that it was deafening or anything prior, but I was just starting to get a slight "hammering" on the engine as is notorious for tired injectors. After replacement noticed an immediate sound reduction at idle, and also at highway speed (and everywhere in between). I can hear the boost kick in clear as day on the highway now, whereas before it was getting overshadowed by the engine noise. I honestly can't believe it...money well spent. Looking forward to seeing what this does to my fuel economy, which was down to 22-23mpg (though not bad for a 110 with terrible aerodynamics and 235/85-16 KM2s).
So here's a play-by-play best as I can recall, with PICTURES BELOW matching up to each numbered step:
1) Remove the hood - just helps to make more room under the hood for working.
2) Before getting started, CLEAN the engine around the injectors thoroughly...you don't want any gunk/etc falling down into the injector holes once you remove everything. I had recently degreased my engine so it wasn't too bad, but hit it with Brakleen anyhow to get any residue off.
3) Crack the FUEL SPILL RAIL bolts (I think they were 12mm), but be gentle - you don't want to snap/strip these, and they shouldn't be on there too hard anyhow. Start with one and work your way down as you'll be moving the entire rail out of the way.
4) Move the spill rail out of the way once all the bolts are undone.
5) There is a bracket/plate that holds each of the injectors in place, and each plate is held down by a nut fastened to a stud. Undo each of these and remove the nut (NOTE FOR LATER: when putting these back ON, be careful not to over-torque them...I cracked one of the studs on reassembly - but it was a quick trip to the hardware store for a replacement but could have been avoided).
6) Once each nut is removed on the bracket/plate, move to the fuel pipe connection at the top of the injector. Likewise, crack each one first - being gentle - and then remove each pipe from the injector. Be careful just to gently move them to the side, keeping in mind that the pipe goes directly to the fuel pump and is a hard line so you want to make sure not to bend/kink these. But moving them out of the way will allow you enough room to work for injector removal.
7) Pic of the injector once everything is disconnected.
8) The next step is to see if the injector is "stuck" to the block, or if it moves freely and *hopefully* will come out. I put a 15mm wrench on the injector and gently wiggled everything back and forth to check for movement and ensure that the injector would come free easily. I lucked out, each injector moved back and forth without a problem - though from my preliminary reading "stuck" injectors can certainly be an issue. Other options if this happens are: a) affix a slide hammer to the threaded end of the injector and remove...this is the preferred method, or b) once the injector is unhooked you can use the engine "compression" by turning it over to shoot the injector out...BUT this is not recommended, can be dangerous, and if undertaken one must put a heavy blanket/etc over each injector to absorb the injector as it shoots out - again NOT recommended and I take no responsibility for issues with this.
9) Once each injector was unhooked and I verified that each was wiggling and looked loose enough to remove without issue, I simply put a pair of vice grips on each to get some upward leverage and wiggled it up and out. During this motion, the bracket/plate that holds each injector in place will also work it's way up and eventually you'll be able to slip this plate free once it clears the mounting stud that each holding nut affixes to (but you'll recall we had previously removed each nut from the studs).
10) Pic of the plate/bracket that holds the injector in place coming free.
11) If you're lucky - like I was - your injector will pull free and come right out as shown here.
12) Make sure the injector has the copper washer on the end of it, you don't want this to accidentally be stuck down in the injector hole on the block otherwise you'll have a leaky injector gauranteed.
13) Get your new injector out and ready to go in.
14) Slip a new copper washer on the injector...you DEFINITELY want to put on new washers, do NOT recycle the old ones or they may be prone to leak, causing you more headaches than the $0.50 for each new washer.
15) I used a dab of grease on the copper washer before putting it on the injector in order to help it stay put while I inserted it back into the injector port in the block - keep in mind you're turning this upside down so you don't want the copper washer to slip off and fall into the injector hole since fishing it back out would be a pain in the arse, so the grease is just helping to fight gravity and keep it stuck to the injector.
16) Speaking of copper washers, each bolt on the fuel spill rail (taken off in step 3) has two copper washers on each bolt, one on the outside and one on the inside as shown here. Make sure to likewise replace each of these washers as well.
THAT'S IT! Essentially, reverse the steps slipping the new injector into each port, hook everything back up, snug up all bolts/etc, and you're all set. While you're in there, you may want to inspect the fuel spill rail rubber tubing (with the cloth sleeve) to make sure it is in good shape. Mine looked fine, and I opted not to replace it...though to be cautious I probably should have and will in the near future - but this can be replaced without taking anthying apart so it can be done at any time.
WORD OF CAUTION #1: as I mentioned above on #5, when torquing the injector bracket/plate that holds the injector in place, these slip over a stud that protrudes from the block. There is a nut that then fits on the stud and you tighten up to keep things in place. I over-torqued mine and broke it right off...so I had to hit the hardware store for a replacement (which I think was just a standard automotive M8 stud that worked just fine). The LAST TWO PICS show the broken stud and the hole where the stud screws into the block. This probably applies to all of the above steps, take it easy and don't feel the need to "Hercules" anything like I did.
WORD OF CAUTION #2: on first test drive, I noticed one of my injectors was leaking. Took it home, popped the injector out, and there was a lot of crud that must have fallen in the hole when I removed the injector...it was caked to the copper washer and was preventing it from making a good seal. I cleaned everything off, reassembled, and it didn't leak a drop after that.
All-in-all, if I hadn't broken the stud I probably would have been done with this in less than an hour from start to finish. Honestly, it was unbelievably easy and straightforward - and again I notice positive results from the new injectors right away. I highly recommend it for anyone that is in the 70k-80k mileage range like I was.
If there's anything I missed or something that people would like to add, feel free - just figured this may help others that are contemplating an injector change in the near future.
