Since the car is down, I have also decided to remove the injectors and have them rebuilt. I am having difficulty removing the rails. How much pressure can I apply to these without damaging them? Are there any secrets I am missing here? Again, any tips would be greatly appreciated.
Modulo Jim's suggestion to fix one thing at a time, the injectors
require a fair amount of force to get out, certainly a lot more than I
could exert directly. Also if I had been able to exert enough force
directly, I could not have stopped quickly enough once they broke free
to prevent damage (I couldn't get the electrical connectors off with
the injectors in). I used a prybar wrapped in duct tape. I wrapped a
loop of insulated electrical wire (one strand from standard household
romex wire) around an injector, twisted it tight, made a loop a few
inches above the injector and inserted the prybar into the wire loop.
They popped out very easily and under control.
If and when you do try to take the injectors out, try the following:
Spray some WD-40 where the "O" rings of the injectors go into the
and/or intake. Wiggle things around a little bit. Not too hard, but just enough
Open a beer or cold beverage of your choice and watch TV. After finishing your beer/beverage, repeat the WD-40 and wiggling procedure.
Think about having another beer, but decide it's probably not a good idea if working on the car, have some other beverage and watch more TV. When the second beverage is finished, try pulling out the injectors again. You should find that they came out with a lot less effort than the first time you tried to get them out.
Of course YMMV, but the above worked for me.
'88 928S4 Auto Black/Black "PORSCHE" cloth
I successfully removed my intake manifold last night. While in the process of removing it I tried pulling the fuel rails with the injectors but no joy.
Since it is my first time, I was worried about the amount of pressure I should be using out of fear of damaging something. So, I unclipped the injectors and pulled the fuel rails by themselves. Now the task at hand is getting the injectors out of the manifold. I can rotate them, but when I give them a hard pull, they don't pop loose.
The key is leverage, not sheer strength. If you just pull on them, you may not be able to stop pulling fast enough when they break free to avoid other damage to the car or yourself. I used an L shaped pry bar, wrapped in a layer of duct tape. I took a strand of romex (house wiring wire) with the insulation still on, made a figure 8 around the injector, and pried up with the pry bar in the upper loop of the 8.
They pop out easily, and the process is easily controlled.
intake done, twice
When I did them, I had them still on the fuel rail, and used a crowbar to
pull it all up with some care.
A little here, and a little there... You get the idea...
The first time, it took a lot of force. The next time was much easier...
The next fun part you'll have is getting them back in. ;)
It seems that the outer surface of the O-ring welds to the intake.
The inner surface of the O-ring does not weld to the injector, but there is enough lip on the end of the injector that it is very hard to pull it out of the O-ring while the O-ring is captured in the intake.
> And am I right that removing the rail first is the hot setup?
I think it's easier, though I haven't looked at a pre-S4.
I find it very hard to get the wiring harness connectors off without taking the rails off first, but it's a breeze without the rails in the way. And I'd rather pry on each injector one at a time with wire wrapped around the solid metal base than on the rails which while pretty beefy (at least on the S4) could get bent up.
Because I was having problems removing the injectors with the fuel rails, I
pulled my intake manifold with the injectors in place. They seemed a bit stuck.
After the intake was off, I lubricated and swiveled each injector.
To pry them out, I used two medium crescent wrenches. I snugged wrench-one down at the base of the injector; not tight, just snug. I took wrench-two and snugged it down on the handle of wrench-one at 90deg to give me leverage, then slowly rotated upwards. Each injector easily gave up its purchase and slid out.
This really made removal easy and is a non-damaging method. You could put some tape on wrench one where it pivots on the intake manifold. Make sure to protect the squirt end when working on the intake manifold with the injectors still in.
'89GT (Injectors shipped off for cleaning)
The injectors can be pried out of the manifold. I use a pair of long needle
nosed pliers with a bent tip. The body is metal and the manifold is aluminum so
there is little chance of much damage. The worst that happens is the plastic tip
breaking. These come in the kit with the new o-rings.
Harbor Freight sells a set long needle nosed pliers with various bends for under $20.
Dan the Pod Guy
The injectors are very often hard to get out. The o-ring dries up and becomes
very hard. It's easier to get them out once the intake is removed. In some
extreme cases I have used an exacto knife to gently slice the o-ring. Other than
that, the injectors are free to rotate where ever you need them. I find it
easier to put the injectors into the rails, then into the manifold.
'88 S4 5spd