Video: Tips/suggestions for changing injectors

[pdeason]

I will be replacing the injectors in my car soon. I have read about the procedure, watched the video and it seems pretty straightforward. Are there any tips or suggestions that might make the job go easier? Also, what other components should I replace while I have the plenum off?

 

[vetteboy86]

Do you have a factory service manual (FSM). It is completely doable without, but always having a good reference is very helpful.

I can tell you that the best advice I have is take your time. Allow twice as much time as you think it may take. I changed mine in an afternoon. I was working very hard, and taking brakes. Take pictures also if you dont feel confident in getting everything back together.

Have you considered doing any plenum porting while you have it off?

 

[vetteoz]

If removing the runners , Don't forget the 2 hidden bolts holding the runners to the intake manifold accessed from the opposite side!!!!!!

Pulling the pump fuse and running engine until it stops only removes the pressure; does not remove the fuel from the lines.
Remove the rubber boot under the fuel filler door and disconnect the 2 rubber fuel lines.
Then when you disconnect the hoses at the rail you will only drain the lines. Too much fuel in the tank and the lines can continue to siphon out because tank is above engine level.

Read and print this out .Everything you need to know with pictures
http://mysite.verizon.net/brianjbalogh/tech/InjectorRemoval.pdf

 

[pdeason]

I do not have a fsm but plan to get one in the future. Not in time for this job though.

I will plug the fuel lines to prevent siphon. What is the purpose of draining the coolant?

 

[pdeason]

Also, some say to lube the o-rings with petroleum jelly, motor oil, silicone...but the instructions at FIC say to use Palmolive dish detergent. I am inclined to follow their advice since it is their product I am installing. Any thoughts?

 

[gmjunkie]

Also, some say to lube the o-rings with petroleum jelly, motor oil, silicone...but the instructions at FIC say to use Palmolive dish detergent. I am inclined to follow their advice since it is their product I am installing. Any thoughts?

Go with Jon at FIC's advice!! He knows his Product and Fuel Injection,He'll not steer you wrong!!

 

[vetteboy86]

I don't believe I drained coolant when i did mine. :confused

 

[KANE]

I will be replacing the injectors in my car soon. I have read about the procedure, watched the video and it seems pretty straightforward. Are there any tips or suggestions that might make the job go easier? Also, what other components should I replace while I have the plenum off?

If you want some pictures & a short how to that goes hand in hand with the video- here is a technical article I posted to the CAC a few years ago.

FWIW- this is a great time to bypass your throttle body's coolant passage too...

Hope that helps- good luck!

 

[vetteoz]

What is the purpose of draining the coolant?

Late at night ; was thinking you were removing intake base :bash

 

[vetteboy86]

If you want some pictures & a short how to that goes hand in hand with the video- here is a technical article I posted to the CAC a few years ago.

FWIW- this is a great time to bypass your throttle body's coolant passage too...

Hope that helps- good luck!

His geographic location would definitely allow this modification. FWIW, mine is bypassed. Did it improve performance??

 

[KANE]

His geographic location would definitely allow this modification. FWIW, mine is bypassed. Did it improve performance??

FWIW- the mod just made maintenance easier. I could tear down the upper plenum, TB, rail, runners, etc without worrying about the coolant.


If it did positively effect performance, it was more about consistency and less susceptibility to heat related air charge loss due to the hot water in the TB.

 

[G Winter]

Also, some say to lube the o-rings with petroleum jelly, motor oil, silicone...but the instructions at FIC say to use Palmolive dish detergent. I am inclined to follow their advice since it is their product I am installing. Any thoughts?

I asked Jon about this. He said , do NOT use oil or grease. He said silicone spray is fine. That is what I used. I didn't have any Palmolive and was concerned about chemicals in other brands.

Glenn

 

[Schrade]

Lots of tips and pics here (LT1).

 

[pdeason]

Lots of tips and pics here (LT1).

I understand that this is a good opportunity to take the center four bolts out of the heads, put threadlocker on them and re-torque them to prevent oil from leaking in that area. What kind of threadlocker? The Permatex blue or red? I am thinking red since these are bolts that should not need removing under normal circumstances. Also, the 1991 has aluminum heads so the torque is 25lbs I believe. Since it is aluminum, should that be done in two steps (say 20 and then 25) or just one?

 

[vetteoz]

Also, the 1991 has aluminum heads so the torque is 25lbs I believe. Since it is aluminum, should that be done in two steps (say 20 and then 25) or just one?

I just torque them straight up in the correct order.
FWIW ;
every L98 I have worked on has had the end bolts by the coolant passages loose.
A water leak from this area is common on L98's for this reason.

 

[Schrade]

I just torque them straight up in the correct order.
FWIW ;
every L98 I have worked on has had the end bolts by the coolant passages loose.
A water leak from this area is common on L98's for this reason.

I've seen 2 L98's with leaks BOTH at the driver's side intake-to-head over #7. Second one found only when housecleaning/gasket swap. Never caught it in the act... ad

If your torque wrench is a budget piece, allow a few extra ft/lbs error. I'm scared of stripped aluminum heads YUP. That sick-in-the-gut geelin' when you think you bored out a spark plug port is a SICK feeling.

 

[pdeason]

I changed out the injectors this weekend. Oh my!! The job is not that difficult but I had one problem after another. The vacuum pipe for the brake booster would not come off since someone had already rounded off the flair nut. I had to take the distributor cap off and snake the whole thing out. That took an hour. The bolts on the bottom side of the plenum runners are so hidden that I could not get my t40 socket in there so I had to get a long-reach t40. Another hour. Those bolts still would not come out until I took the injector wiring harness loose and moved it out of the way. Snapped the plastice tabs off when I tried to remove them. They were stuck to the jam nut that is underneath. I had to remove the driver's side valve cover because I could not get a good angle on one of the runner bolts. There is a black plastic box with some large vacuum lines running to it that sits between the compressor and the throttle body. Not sure what it is but it is in the way for removing the fuel lines. It is bolted by a long tube to the alternator. I had to loosen it and swing it a little. Small pain. Go to remove the fuel lines and neither a metric or standard flare wrench fit very well. It was the cheap ones from Autozone so that might have been why. I ended up using a small adjustable wrench and that work without damaging the nut. When putting the intectors back in, the instructions say for the Bosch IIIs to put them in the intake first and then set the fuel rail on top. I did this but it is difficult to see the that they are in the rail just right. On the first attempt I must have had a piece of grit on the o-ring because it was spewing gasoline. I checked and there was a tiny nick in the o-ring. I replaced the o-ring and tried again. This time I had two injectors spewing at the fuel rail. One was not seated properly, the other one I had torn the o-ring. The third time I decided to put them in the fuel rail first because it is easier to see the intake hole than the fuel rail hole. That time it did not leak. I left it on for at least 30 seconds and no sign of leaking. I assume that if it did not leak then that it is not going to leak later. I realize now that the injectors go in very easily and no force is needed. Once the fuel rail is bolted down they will stay put and not leak.

After all that, and moving my daughter back to college Saturday, I was pretty well exhausted so I did not finish putting it back together. My son was pretty bummed because he wanted to drive it to school today since it is their first day back. I will put it together this evening when I am fresher and hopefully won't miss anything.

I think the phrase "never again" comes to mind. It's not that I mind doing things like this, it's just that I have no time for it and this is my son's daily driver so I have the pressure of getting it back together and working in a short time frame. I also was a little nervous since a leak would be a major safety issue.

Looking back on it, I might should have just spent the money and had a shop do the work. If it leaks once I crank it I may well do that anyway.

 

[pdeason]

My son and I put the car back together last night. That was also a comedy of errors. The first thing I noticed was the passenger side runner, which won't go on with the fuel rail installed, was actually the driver's side runner.

I remove the bolts and lifted up the fuel rail, slid it out and the other one in. Retested for leaks and continued on. I had already bolted on the pipe that goes from the manifold to the intake (not sure what it's called) before I realized I needed it off in order to access the inside runner bolt on the back. It also took a little while to figure out where all of the runner bolts went. I also had not noticed that there is a difference between the runner bolts and the upper plenum bolts. The runner bolts have square shoulders and the upper plenum bolts have rounded shoulders. (remove the bolts that do not go there and continue on) :bash

Spent quite some time getting the driver's side valve cover back on. Note to self...If you think it would be easier to remove some connections, hoses, wires, etc...DO IT! You are much better off in the long run.

The upper plenum was not too difficult with the exception of getting the holes to line up while keeping the gasket from moving.

Rolled the car out of the garage to start it up (leak, fire, garage...not good). My son tries to start the car and I notice that the metal brake booster pipe has not been connected to the back of the plenum. What a PITB. It took 30 minutes and considerable sweat to get that flare nut started. My son then looks at me and says "Are you ready?". I tell him not really but try it anyway.

The starter turns for 3 or 4 seconds and the car fires. It stumbles a couple of times and then catches, purring like a kitten. I look for leaks at all the injectors and fuel line connections and see none. Then I noticed coolant dripping from the bottom of the throttle body. Somehow I had wiggled that connection loose. I secure it and started the car again. Let it idle for 15 or 20 minutes while cleaning up the tools.

I get in the car and back out of the drive only to notice that the temperature guage is maxed out at 260. :confused There is no way the car is overheating that much on a cool night at 10:00 after only 20 minutes of idling. I shut the car off, and check the coolant temp sensor on the side of the block and the one under the plenum. All looks good and the car does not seem like it is more than just warm. I also notice gurgling coming from the coolant system. After a few minutes I restart it and the temp is about 200. We drive it around for a little while and the temp stays pretty steady at about 200-205. It must have sucked some air into the system when it was leaking while running. Will have to bleed the system later.

The good news is the car is running like butta. It idles smoothly with no surge. When coming to a stop it drops normally and seems like a brand new engine. The problem must have been the injectors all along.

Thanks for all the help and advice I have received on this site. I could not have done it without you all. Also, I bought the injectors from Jon at FIC. The price was nice ($170) and he was great. I called him one time over the weekend on his cell phone and he helped me without the slightest hesitation. If you need injectors he is the one to call!

I love it when a plan comes together. :L

 

[LT4man]

Congratulations on a job well done! I know you ran into some problems along the way. Welcome to the "World of Auto Mechanics"! Even good technicians run into issues on almost every car they work on.

Nice to hear you are happy with Jon @ Fuel Injector Connection and his products. My LT4 has never run better! Jon is the BEST and deserves all the kudos he receives!

Just make sure you get some time in the driver's seat!

AFTER INSTALLING YOUR FIC INJECTORS, DON'T FORGET TO SAVE THE !