changing my fuel injectors

[argniest]

I have 6 new injectors I want to install in my 1978 280z. And I also have some new quick disconnects for them too. But I planned on installing the quick disconnects later, as a second step.

Can anyone give me any pointers, tips, tricks, traps to look out for when doing this job? I have read over the procedure in the FSM, and been studying the fuel injection system in the car. It seems fairly straightforward. I will take my time, am in no rush, I just dont want to mess anything up that costs me a LOT of money or heartaches.

I am NOT a mechanic. Never done anything like this before. But I bought the car to also help me learn how to work on things like this and feel rewarded for doing it once and doing it right :-) In general, I am good with hardware electronics, computers, gadgets.

And I have just completed the cleansing of all the main electrical connections and grounds in the car, and cleaning the fuse box and replacing all fuses, and I have completely disassembled and reassebled all the plastic pieces inside the car. So I could look for rust problems (didnt find much problems at all thankfully) and also install some new speakers and a custom speaker box in back that looks like it was made for the car. :-) I have also replaced the air flow meter, and a few other things on the car. Sooooooooo I have done a few things on it so far this winter.

On another post on this forum I have described various problems with the car, and also a few Z mechanics have said it would not be a bad idea to change them. As long as I had the money. So I am hoping for some advice here before I dig into the job.

I have the new injectors and new o-rings.

PS

I did try to turn one of the screws holding in the #6 fuel injector, and it did not budge. So right there I see a big problem. The screws holding in the fuel injectors seem kind of soft to me. As compared to other screws I have seen. Dont know if that is just because they are 33 years old and never changed or what.

I suppose I need to squirt some anti lock/antifreez oil stuff (is it called lock tight?) on the screw heads and maybe a few other places along the way....there to help loosen them up? And leave it sit overnight I suppose or maybe longer.

And even though I have a bunch of screw drivers, I need a longer version, so I can apply some good pressure to the screw with both hands on it.

Edited January 21, 2011 by argniest

[argniest]

Dumb question but here goes....is it possible to change out any of the fuel injectors without removing the fuel rail?

Because I am convinced after talking to z mechanics and showing them my plugs, that the #6 fuel injector is definately not working correctly, and I may be running on only 5 cylinders because of it. That is what a very experience mechanic told me 30 seconds after driving the car. That I was only running on 5 not 6 cylinders. Then I showed him how fouled up spark plug #6 was.

[Zed Head]

It is much easier to get to the injectors with the fuel rail removed, otherwise you have to tweak and bend the rail. They're all mounted to the rail with the same very short piece of fuel line, which gives very little wiggle room.

I highly recommend buying a high-quality #2 Phillips head screwdriver before attempting to remove the screws. It is very easy to strip the heads of the screws if the bit does not fit perfectly. If you strip the inside of the head you'll have to get in there with Vise-grips or some other tool. Avoid that at all cost. Craftsman brand (bought at the store, not internet) has a very good fit.

The popular penetrating oils are PB Blaster, Liquid Wrench, and Kroil to name a few. You should spray it around the base of the injectors where the screw's threads are. Spraying at the top might not get down to them. Spray it on when the engine is warm if you can.

[argniest]

thanks for tips. will definately get the liquid wrench stuff or PB Blaster or Kroil. Whatever they have at Ace. And I will get the #2 phillips....I big honkin one too. That I can tork on. But carefully of course. And I will have to warm up the engine as you said, and then spray #6 on both screws. I will also spray #5....just to see if I can turn any of the four screws. If not...then I have a whole other problem to think about.

[sblake01]

Purchase some allen head screws to replace the original screws. Also, before you pull the injectors, make sure that #6 is getting a signal. It could just be a bad connector.

[FastWoman]

^^ What Steve said!

The FSM and many Z people say the easiest way to remove the injectors is by removing the injector screws and pulling the entire rail. However, I see no reason you can't cut the injector hoses, remove the rail, and then work on the injectors individually. This would give you more working room.

When I installed my new injectors, I first populated the rail and then tried putting the assembly in as a unit. I found that was about as easy as putting a cat in a sink of water for a bath. I then pulled off all the injectors, installed them individually, and then pushed the rail barbs into the line of hoses. Much, much easier.

When removing the screws, keep the screwdriver perfectly straight. First tap the bit into the recess with a hammer. (Don't get carried away.) Then apply very firm pressure while you turn.

If you end up stripping the head, you can drill it off and pull the injector out over what's left of the screw. Then you can deal with the remainder of the screw with another long soaking in PBlaster and then a SMALL pair of very new/sharp vice grips.

[Zed Head]

argniest, if you have not done much mechanical work, there is a high probability that you will strip a screw head. It takes some practice to get the feel for when the tools are working right, plus it takes some correctly applied strength to get them out if they're very tight.

Another option for you might be a #2 screw driver bit used at the end of an extension, on a ratchet handle. This would allow you to press down on the ratchet head, and use the leverage of the handle to turn the screw.

Just offering alternatives. I have been turning screws, nuts and bolts for years and I still had problems getting the screws out of a manifold with the original injectors in it. Watch the screw head and if the bit starts to slip, stop and readjust. It's a sick feeling, looking down at a rounded out phillips head screw.

[DatsunZsRule]

I too have done this lovely job on my 280Z about a year or so ago. Be happy you have the one solid piece fuel rail on the 1978. On the 1975 - 1977 like mine the rails are all pieced togeather with short sections of high pressure F.I. rubber hoses connecting the fuel pipes A - D togeather. I had to disconnect all those and replace all those short sections of hose as well as the injectors. Now THAT requires major skills and patients

I'd recommend installing new plastic injector holders. I did on mine being those tend to get old and brittle over 30+ yrs. One tip for you with the top and bottom 0 rings, Give them a light coat of 3 in 1 oil to help them go on easily and help them seat good. I think it was Stephen that gave me that pointer Thank you.

For the screws - It is very common that they tend to seize on over the yrs. With the proper size screw driver and with me applying plenty of pressure, mine all came out with no problems or damage. DON'T use Lock Tight as noted in your 1st post thats what you put on screw threads so they don't come loose. You want them to come out Just soak them good overnight as suggested above with a good penetrating oil. If it does happen to you where you stip the phillips head, this is what I have had good success with http://www.amazon.com/Alden-8440P-Grabit-Damaged-Extractor/dp/B001A4CWHO

A little spendy but well worth it in my honest opinion. If you get all the screws out Ok like I luckily did, then do what Stephen suggested or do what I did and put a very light coating of anti-seize on all the screw threads incase you need to remove them again in the future.

Just take your time and be patient and follow the help & tips on here and in your FSM and you'll do fine Biggest thing again is patients. Don't attempt that kind of job if your busy and short on time. If you do, you WILL loose your cool and mess something up.

Take care and best of luck.

[argniest]

Thank you all, for your advice. I am soaking it all in!!!! I will be very careful when trying to turn the screws. I will soak all of them with the Kroil or PB buster. I have both products on hand. I have soaked two of the sets of screws with each product. And will see if one works better than the other. ALso, thanks for the URL. I am going to order those things (or see if I can find them locally first) just in case I really did ruin a head. Which I will not do, because I wont let myself get that far anyway. If its not coming loose after soaking and **tapping** it with a hammer as you mentioned above....then I will regroup.

I am glad to hear my 1978 has an easier to deal with fuel rail.

And I will use some anti-sieze goop on them (before putting back in), assuming I do in fact get them all out. And I will also look into getting a different style of screws as you mentioned above. I dont like the idea of putting them old ones back in. Not at all. SO I better get those ordered. I just need to know for sure I am getting the exact kind that I need. Can anyone tell me exatly what kind/type/brand/size I need to get to replace those old screws?

One thing, would it be better if the engine was warm when trying to remove the screws. I have mixed feelings about that. Part of me says that if its warmer the metal will have expanded and make it tighter, but then maybe if its warmer, it will make things like the lubricant penetrate better and make it easier to remove????

EDIT: Well I went out there today to see if the Kroil worked!!!!!!!!!!!! And yes, I was able to turn all 6 screws on the first three fuel injectors 6 5 and 4. So that is really good news for me. I just avoided a lot of potential problems. Now I am pretty sure the other ones will turn out just fine. I will let the Kroil soak over night and try the other 6 screws tomorrow. Then I can work on fuel injectors without worrying about any of this crazy stuff happening.

Edited January 22, 2011 by argniest
I DID SOME!

[DatsunZsRule]

Good to hear your having good success with the screws. I was able to reuse mine as they were still surprisingly in like new shape being the car is a low mileage Arizona Z car. I Just put a thin coat of anti-seize on the threads before reinstallation and she was good to go Thats a very rare thing. I was lucky For sure inspect them and replace them if they seem the least bit worn looking.

As for the Grab It set, you should be able to locate them locally. I bought mine off the tool truck where I work but I've seen them at hardware stores before too. Just have to shop around in your area. They sure have come in handy for me more than a few times. never did have to use them on my Z yet though (Knock on wood)

Yep, I have the last year for that fuel rail set up (75-77) Very fun job

Take care.

Edited January 22, 2011 by DatsunZsRule

[argniest]

Well, all the other screws turned for me without any problems MAN WHAT A RELIEF THAT IS!!! First, I lightly rapped on the top of the screwdriver with the hammer after sticking the nice long hardened phillips #2 down on the screw. I used Kroil on all of the rest of the screws this morning. Let them soak for 14 hours at least, and just went out there a little while ago. And I was soooooo happy they all turned. That is so nice, now I can do the fuel injectors without worrying about causing me major problems with those screws SWEET!

I will inspect the screws closely. If they look in bad shape I will replace. I just got to find out exactly what size/type to get as I mentioned earlier...I would prefer to just get or order the replacements for them, so I have them on hand when I get ready to do the job. If I dont use them, oh well I dont really care. There is nothing so frustrating to me as getting 99% of the way prepared to do the job only to find out you dont have the one thing you need to finish

Edited January 23, 2011 by argniest

[sblake01]

You don't have to order them. Take one of the screws with you to a hardware store and match it up. Try to get the new ones in stainless steel if possible.