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changing efi hoses on 78 280z


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I'm also using the Standard injectors. Mine work great.

FAIW, I've found it much easier to re-install my fuel rail onto the injector hoses after fastening the injectors first into the manifold. The "easy" way of removing and reinstalling injectors and rails en masse was quite frustrating, both on the removal and on the attempted re-installation.

This line of clamps is fantastic, BTW:


(comes in various sizes)

It doesn't cut into the rubber, and it's very flexible -- great for small hoses.

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The injectors sounded like they were clicking ok last it ran. One of them has melted plastic along the body, I have mixed feelings about that. There's an FI shop around the corner but he was closed. Sad face.

So I spent the day cleaning around there. Used most of an engine brite. Also wanna clean the connections while am at it, as per atlantic z.

I found one of the plastic injector holder was broken on one of the screw holes. Nobody has it in stock. Since its just a holder would it be fine? Might the FI shop have some?

Oh and what can I expect when getting them cleaned/tested? New o rings?

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A good shop will ultrasonic clean them, replace the small inlet filter and the plastic tip. Flow test them at different speeds.

They can't recondition them because they can not be dismantled. If they measure coil leakage in the injector the only option is a new one. Same goes if the needle does'nt seal properly after cleaning.

Check the link I posted above to the Hiperformancestore. If you scroll down the page you will find the section on injectors. It gives you a good idea what you can do with your injectors.

A quick test you can do at home to see what spray pattern they have:

Connect about a metre of 5/16" fuel hose to the injector and fit a air hose coupling. Use about 15 to 30psi pressure. Connect a 9 volt battery to the terminals to activate the injector. Let is spray into a clear container to see the patern. You can also time how long it takes to empty the hose and repeat the procedure for each injector. Its a rough test, but gives you an idea of what the injectors condition is.

Dont use 12 volts on the injector. That will probably burn the coil an render the injector useless. When they are on the car they pulse and that averages out at about 7.5volts. A 9 volt battery for +/-10 seconds wont cause any problems.



Edited by EuroDat
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Nice, thanks for all the tips everybody. Looks like another day off, which is +/-. + for the z, hehehe. Today ill go to the FI shop and try my luck at Nissan for those screws. And maybe scout around for that one holder.

It got a decent cleaning session yesterday. Most connectors were fine, some were slightly green. Does not have fuse links. It has a newer cable that has a fuse that is wired to the fuse box, I think. Don't know if that's a good solution.

PO: I checked all the wiring, I even fixed some.

ME: wow, so you know a lot about these cars?

PO: Nothing. A friend helped me tear it down. He said these cars are easy. He's an electrician.

ME: wow, so has he worked on one of these before?

PO: He's does residential.

So I'm sure ill be posting a thread in the Elec section soon, hehe. But hey, its like that Cash song, one piece at a time...

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dropped off injectors at the shop. said he was gonna keep them overnight. wasn't expecting that since i was planning on it taking a couple of hours so i can spend the afternoon installing. called Nissan about those hex screws and said they only have it in stock in OR. ugh, gotta scout for some screws. so didn't really do much yesterday other than clean some more connectors.

when i took the rail off i found a broken tube that was glued back on:


is this important?

i need it to pass smog so i can get my pink. anything else i can do to help pass? might have a shop help me out with this one.

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Thats the Thermal vacuum switch. I broke mine too. There around $20 at Advance I think, used on many cars too. Couldn't get mine out so I did away with that whole coolant plate but I've no smog monsters here in Alabama. google it. glue it back in just don't stop up the hole. should pass, thing switches from ported vacuum to manifold vacuum after it heats up, I THINK. Not positive on that though

Edited by siteunseen
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Siteunseen is right. Its the Thermal Vacuum Valve for the EGR valve. If you cant remove the EGR because of smog regulations in your state then try to repair or replace it:disappoin

The TVV doesn't allow vacuum to the EGR untill temp is above 45degC, 110degF.

The EGR doesn't work at idle or full throttle because their is to little vacuum to open it. The other condition is if the exhaust pressure is under +/- 30mmH2O the BPT valve won't let the vacuum open the EGR.

I had to order the screws when I replaced them. Took about a week to get them. You would think something like that would be standard, but apparently not:ermm:

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Ace Hardware has a good selection of metric screws. You could probably find one that will do the job and replace them later if you want the hex head factory screws. A Phillips head screw isn't going to corrode in place and bind up in a few days.

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no i think i'll just glue it back, hehe. seems like it'll be fine.

should i be worried that it won't pass smog? it didn't smoke or anything but did shoot crud out of the exhaust before parking it. i thought maybe the leak was the culprit.

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Hey J do yourself a favor and buy those injectors that Fastwomen and siteunseen mentioned. IMHO. After chasing a lean condition I finally bought those injectors and after I installed them every little problem I was having went away. I have 277,000 miles on my 77 and she now purrs! It's a joy once again. I had my old injectors serviced and it changed nothing sending me in the wrong direction during my diagnostics. A mechanic friend of mine said "trust me and replace them" so I did and am glad I did!

Edited by rcb280z
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