My fuel injector change improved:)

[vilant]

So I decided to change out my fuel injectors, coil packs, spark plugs and wires. I used the LT-5 supplement manual and engine tear down 1 on Solutions. First I drained the coolant, then removed the 5/16" negative battery terminal. Remove the air intake and accordian from the plenum. I put the 2-10mm screws back into the holes for safe keeping. Remove the T-15 screw and 7-mm nuts from the cable shield.

I labeled everything in this project w/ blue painter's tape for 2 reasons: 1- to make sure every screw goes back into the spot it came from, and 2-it helped me remember everything I was doing, plus if you see any blue tape left at the end you know you missed something. So, next remove the cables from the pulleys. If you reach under then and pull up, it will give you slack you need get them free.


Pull the plastic retainer from the bracket.

Next in the supplement manual it says to remove the fresh air hose from left and right side of the throttle body extension. Problem is (at least on my '90) there's no room to remove the hose from the cable side. So, that comes later.

Remove TPS, IAC, and MAT connectors. Remove the coolant hose from the plenum (I removed it on the passenger side),

[vilant]

Remove the power brake booster hose from the plenum and the vacuum hose between the fuel pressure regulator and plenum. The ports are on top of each other on the back, driver side of plenum.

Remove the vacuum hoses from the mid-plenum: left and right. Remove the vacuum hose between the MAP sensor and the plenum. I disconnected the electrical connector and took the whole MAP sensor off, it's only held on w/ 2-T27 screws, it's attached to the back of the plenum. Made it easier for me at least.

Open the gas tank cap and connect a fuel pressure gauge(w/ a bleed valve) to the fuel rail port on the passenger side. Relieve the pressure in the fuel rail to a suitable container. Remove the 3- T40 from the fuel lines. I had to this because one the plenum screws is blocked by these lines and I found it easier to leave the fuel rail on the ground later. There'll be gas left, so have a rag ready.

[XfireZ51]

I actually do not remove the throttle cable. Mostly I pull plenum and lay it down on the driver's side tire, flipping it over onto a shop towel.

[vilant]

Remove the 12- T40 screws holding the plenum down. I labeled each screw by where it came from on the tighting sequence.


It says next to remove to purge solenoid/ PCV vavle hose fitting from plenum. Problem I had was the PCV valve pipe was pinned under the coolant elbow on the passenger side.

So I left the pipe there. I gently lifted the back of the plenum up so I could at the ignition connectors under the backside of the plenum. One of them is held on w/ a 1/4" hex head screw.

Same picture as before I know. But it shows the connectors too. Now lift the back end of the plenum up gently, because there's still another 2 connectors and a vacuum hose underneath. Remove these.

Now gently lift the plenum. The fresh air hose on the driver side can now be pulled free while removing the plenum. Here's what it looks like with the plenum off.

[vilant]

Cover the injector housing holes with tape to keep things from falling down in there. Now I read in Solutions how to lift the fuel rail off with a suitable pry bar. My injectors were in there so tight, and I was prying down so hard, that I thought I was going to damage the fuel rail. So, Plan B: I removed the metal retaining clips on the top of the injectors, then pryed. It came right off, but I forgot about the leftover gas, so have a rag ready to save on clean up time. Once I removed the fuel rail, I replaced the coil packs. The original's were labeled and the new ones weren't. So I wrote in black marker on the new ones the old one's number sequence. They're held down w/ 7/32" hex head screws.


I also removed the wire harnesses intact and set them on the driveway. The reason being I matched the new wires with it's corresponding old one. Labeled both ends of the new wire in black marker where you can't notice it with their number. The I took one old wire out then put the new one in the same exact spot. So when I was done, I had 2 exact matching wire harnesses.


Work new wire harnesses through the back, put dielectric grease on the coil pack terminals, and push the wires onto their corresponding terminal.
Now I removed the old gaskets from primary injector housing and installed new ones per Jerry's tech guide. I lubricated all new gaskets(except the plenum) with a little motor oil (just dip your finger in oil and wipe around gaskets). Don't forget about new fuel line gaskets. Install the new injectors into fuel rail, pay attention to the order of primary and secondary. Reinstall the fuel rail and injectors, there's 4-10mm screws to be tightened to 19 ft/lbs. Change all the spark plugs, I used NGK Iridium, anti-seize, and tighten to 19 ft/lbs. I squeezed dielectric grease into wire end reconnected all the wires to the plugs. I should look like this now.

Now follow the reverse directions and reinstall the plenum, tighten bolts according to tightening sequence and to 19 ft/lbs (*IMPORTANT: make sure the TPS wire harness is routed on top of the 2 ports (PCV and Purge) under the throttle cable assembly. Accidentally, put the plenum back on with this cable pinched under the 2 ports. Caused a small air leak because the rubber coupling couldn't slide on all the way. Save yourself 2 hours of aggravation to fix.). I put a little permatex around the 2-coolant holes before I reinstalled it. And be sure to install the fresh air hose on the driver side first. I siphoned gas back into the fuel rail through the fuel gauge valve (not necessary, but did it anyway). Dropped the car down and refilled the coolant fluid. She fired right up (have a video, but don't know how to post it). Of course a hurricane is hitting so I can't take it for test spin for a few days. Only problem I have is there's a small air leak where the PCV pipe connects to a rubber block, under the cable assembly on the driver side. Thinking about putting silicone around it to seal it. Hope you enjoyed this
.
P.S. I might of forgot of something while writing this. Let me know if I did.
P.S.S. Thanks Dynomite for the resizing images tip.

[scottfab]

You might want to clean out the drain hole while you're in there.
Put a long wire down the hole with a small piece of rag tied to the end.
Then get under and pull it through. Depending oh how much crap comes
out you may want to do it again.

Another thing to consider when you've got the plenum off is to either loosen
and retighten the two grounding lugs on the top of the bell housing or take the bolts out, clean the grounding surface and lugs and apply dielectric grease. These surfaces oxidize over time and cause bizarre and random electrical issues. To do the later you have to be good at doing things by feel since vision it tough in those tight quarters.

[vilant]

Originally Posted by scottfab

You might want to clean out the drain hole while you're in there.
Put a long wire down the hole with a small piece of rag tied to the end.
Then get under and pull it through. Depending oh how much crap comes
out you may want to do it again.

Another thing to consider when you've got the plenum off is to either loosen
and retighten the two grounding lugs on the top of the bell housing or take the bolts out, clean the grounding surface and lugs and apply dielectric grease. These surfaces oxidize over time and cause bizarre and random electrical issues. To do the later you have to be good at doing things by feel since vision it tough in those tight quarters.

I cleaned what I could down there, but didn't go crazy. Do you have a pic of where these are at? Or can I find it in 1 of the manuals. I do have flickering dimmering of the interior instrument lights and driver display. Maybe that's the culprit.

[scottfab]

Originally Posted by vilant

I cleaned what I could down there, but didn't go crazy. Do you have a pic of where these are at? Or can I find it in 1 of the manuals. I do have flickering dimmering of the interior instrument lights and driver display. Maybe that's the culprit.

Here is a view from under. I can't find the pics I did from above.

[vilant]

Originally Posted by scottfab

Here is a view from under. I can't find the pics I did from above.

Your not kidding about hard to get to. Is this photo from when you had your engine or transmission pulled? I wonder if it might be better to cut the wire, butt splice to extend, or just crimp new ends on and ground it to an easier location.

[scottfab]

Originally Posted by vilant

Your not kidding about hard to get to. Is this photo from when you had your engine or transmission pulled? I wonder if it might be better to cut the wire, butt splice to extend, or just crimp new ends on and ground it to an easier location.

This view is from under the car when I rebuilt my ZF6.
I suppose you could cut the braided wire and extend.
You could end up getting what are called "ground loops" though.
I have not heard of anyone doing it.