Fuel rail installation

[Magic944]

I can’t for the life of me get the fuel injectors back in. Does anyone know any tricks?

[kdjones2000]

Use a light weight oil on the o-rings and gently work them into the rail.

[wwdwgs]

Some use liquid soap, I just spat on them )))
Also, make sure that mating surfaces are clean, very clean. And the spit should be clean, too.

[Magic944]

Thank you, I’ll work on it later

[Monkey Wrench]

don't try to reuse those o rings, they are cheap. I removed a fuel rail before without the forethought to order them first. I did succeed but I cursed myself since they are only about a dollar each or so.. I'd oil them too.
I read that a trick to see if they leak is to oil them after install, see if the oil gets sucked in.
I was initially kind of half-thinking that they had to stand the compression, but I think the intake valves are closed when the cylinders compress so ( I think? ) that isolates them from the compression stroke?

[Monkey Wrench]

sounds like it might be worth a try, anything that swells rubber isn't' really "good " for the rubber, but if it works, hey, why not and if it fails then you probably arent' much further back.

last year I had a head gasket leak in my volvo so I tried a miracle cure. it didn't work and the process took time I had to drain the rad add the stuff, go through several warming and cooling cycles , drain it and flush with water etc..

maybe it could have worked, had the leak been less severe. when I pulled the head I could see it was sort of "trying to work"

so long as the case isn't dry of oil , I don't see it as having the potential to damage much, if its apart you'll change the o-rings seals etc.
often seals have part numbers much like bearings do and so I can obtain them locally and not as a specific OEM part. If you have something like that apart you can try searching the number on the actual seal if you can read it. It may differ from the part number.

as a kid I had a VW and it had a loose steering box, oh because it was misused on a farm.. It was that first car that I never should have bought and ended up rebuilding..
I tried adjusting the slop out of it, which at first seemed to work , next I was driving over a curved 2 lane bridge and it completely locked up, I actually tried turning into the oncoming traffic and doing so allowed it to move again.

almost killed myself. by the time I got the car off the bridge I could literally spin the steering wheel, the bearings fell apart and it had jammed up. If it has issues of severe slop I'd take it apart. the oil loss is likely not a big expense, just a bit messy. might rot out motor mounts etc.

[Magic944]

I tried a couple methods to try and get them into the manifold. Now one of the fuel injectors is leaking fuel. I don’t see anything visibly broken. I disconnected the fuel supply line for the time being. Anybody know what I did?

[Jfrahm]

Leaking how? From the top O-ring or from the injector body or ?

Do you have the injector clips that hold the injectors to the rail? IF not you might be able to push one down far enough to get the top O-ring to leak, or the top O ring could be damaged.

[Monkey Wrench]

on the end of the fuel injector there is a plastic cap called the pintle.. it has a smal hole in it. that sort of surrounds a sharp thin pin shaped part. if you drop them or bang against that it might do damage..

I cleaned up some volvo injectors and posted a thread on that, what I did was ceated a pressure bottle that I can add cleaner to and pressurixe then open upon the injector to backflush , forward flush and test the spray pattern. Ive seen them stick open and dump the fuel ril into the cylinder. Ive also seen them stick closed then it runs on 3 cylinders with no fuel to 1 of them..

If creating a bottle like that is work, then I have seen a video where the guy just took a can of cleaner and adapted the nozzle to a piece of about 1/2" fuel hose then stuck the injector on and sprayed the can. you can activate them to open and you need to to get any cleaner through. I just used a 9 V battery.

what Ive done as well to test them , just put the car outside, find a proper fire extinguisher, be very careful with this. we dont want you starting a gasoline fire...

if you pull the fuel rail connect the wires all back, put clean dry cloths under each injector, get in, crank for just a few seconds, stop!

run around, look and see. If they dont shut off one will be spurting fuel, it will soak the rag.. if they dont open then you will have a dry cloth there. if everything is basically ok the you will have a neat little circular spray pattern of fuel on each cloth..

a shop can test or rebuild them, none of this addresses a perfectly formed spray pattern.. it just shows if it should work well enough to run the car. you can get rebuilt ones or there are cheap made in china replacements. I'm not sure how well those work.

each injector has a little gasoline screen on the fuel rail side, I just backflushed and found them clear enough but there is a tool to remove them. I think an appropriate sized sheet metal screw on a slidehammer might do ok, never tried. a short bit of chain and a weight can be an improvisational slidehammer. the tool screws down pulling the sheet metal screw to extract the screen, if you need to you can order that tool..

my suggestion is order new o rings, the pintles, there are a couple of plastic washers, its not expensive. If you dropped or damaged the pin on one I'd replace that injector.. I think that pin is pretty sensitive, much like a carburetor jet in a SU carb..

the ECU or MCU changes the duration of power on to each injector. Its giving very short specific pulsations, as the system detects your revs going up and more air going in, it reacts by increasing the dwell time .. It changes the duration of time increment of power to open the injector.. to the injectors to maintain the air fuel mix with a varying amount of air entering. they are normally quite reliable but if the car get parked or you get bad fuel it can plug things up basically..

the fuel tank has a screen on older ones its inside the tak at the outlet.. Its a bit expensive so rather than pay 100 or more I might use some gasoline screen and make my own up. it needs ot be there to keep particles out of the pump, after the pump any little particles shoudl get trapped int eh fuel filter which is working under fuel pressure.

If yours is older like mine is early 85, check the short hose between the tank and pump. mine rotted out and it dumped all its remaining fuel in the previous owner's driveway, that bit of line does rot and it's cheap.. so at minimum check if yours is old and bad you dont wan thte tank to dump your fuel unexpectedly..

heres the link to the thread i did when cleaning injectors. you can see the tool I made for myself, nothing too complicated.. I like that better as I can test them outdoors away from sparks, please don't play around wiht open ful inside your shop.. don't start a gasoline fire. Make sure you have an extinguisher that is rated for a fuel fire right there handy.. just in case.

open fuel can be very dangerous so you wont see a lot of people suggesting you do this stuff yourself, take proper precautions of the dangers if you do any of this. I just wanted to help but I'd feel horrible if you start a fire by doing anything unsafe.. some opt to just take the injectors for a rebuild or repalce..

I think this stuff is a way to just check if there are serious problems, you may or may not find a difference in performance by going ahead and replacing them..

if the pintle is missing or cracked it will mess up the spray pattern.. they can fall off if you arent; careful. best to renew those few small injector parts if you choose to mess with them at all.

if you were pushing hard o the fuel rail you might examine. I don't think its too hard to bend stuff and maybe mis-align them.

i experimented with a tepe deck motor figured I could create short pulses by making a cam and a set of contacts. it sort of worked but ran too fast so I wasnt seeing the injectors open and close instead I simply touched the wires to power the injectors intermittently, less complicated,



here's a link to my older thread thread on injector cleaning..
http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/1145509-cleaning-your-own-fuel-injectors.html

[L Sjoberg]

we just rebuilt the injectors on our son's 86. some white lithium grease on the O-rings, pop them into the rail and then bolt the rail down to the manifold. was pretty easy-peasy, actually, and finally fixed a rough running problem he's been suffering with for several months.

as already posted, don't try to reuse the O-rings. and replacing the cap is also very easy.

[Eskozki]

I had leaking injector without any visible damage and good O-rings, but the plastic body may separate and cause a leak. The leak will show as fuel pooling on the injector hole, above the O-ring. If that is the case then you'll need to get a new injector. If you have replaced the seal and it still leaks, chances are its the body issue.

[Magic944]

I haven’t been able to get around to working on my car much so sorry for the late response. I believe it’s leaking from the lower half but I’ll have to check soon. In the mean time does anyone know of a good o ring and cap kit on pelican? I’ve seen a couple but I have noticed they haven’t worked out for everyone. I have an 83’ so I would need an early car version.