This guide collects what owners reported when changing injectors. For choosing the size, see Injectors for supercharged cars: sizes, duty cycle and what owners ran. The fitting information is mostly from two owners with Dutch ECU cars (Exmantaa and smiley) and a few others, and it has gaps (no torque figures were given in any of the threads).
Removing the rail
- Release the pressure. techieboy (2011) said to release the residual pressure in the rail and pipes using the valve on the hard line running into the end of the rail, with a rag over it so it doesn't fire a jet into your eye. Then put plenty of rags at each end of the rail to soak up the fuel that comes out when you undo it.
- Pull the rail and injectors together. NickB787 said it is an easy job, but you often have to pull hard to remove the rail and injectors together, and the seals at the bottom of the injectors can stay behind. Another owner (Zoobeef) said to check you haven't left any O-rings in the holes when you refit.
- Refitting. Arno asked whether the O-rings were lubed with some engine oil before fitting the rail to the head. The thread doesn't say which O-ring kit to buy.
- Testing an injector. FLD said a specialist can test one in a tank that pressurises and fires it, showing flow and spray pattern. He wasn't sure it is safe to crank the engine and watch them fire with the rail held up, and said it is probably cheaper to swap them, especially if you are given a set.
Why the rail doesn't sit down
An owner in 2018 fitted a set of Bosch 0 280 158 123 injectors with adapters to a Z22SE head and the standard fuel rail. The engine fired up but the rail sat 4 to 5 mm off the head, and he didn't want to overtighten the bolts.
- Nev said injectors differ in length, so he had probably installed longer ones. Exmantaa confirmed that this Bosch injector is a little longer than the Z20LET, VXR or Siemens 60 lb injectors.
- CHILL Gone DUTCH said he never used adapters and had no problem with the black turbo Bosch, the blue VXR Bosch or the Siemens 630 cc injectors. That fits Exmantaa's view that the longer EV14 is the odd one. The Batman said in 2013 that the Siemens 60 lb needed the fuel rail spaced out with GM spacers, so that is not agreed.
- What worked for Exmantaa and smiley. The EV14s on a standard Z22SE rail with the grey plastic insulators (GM ACDelco kit 217-2762) and the extra alloy raiser blocks, plus a small spacer washer between the rail and the two blocks to gain the extra clearance for the longer injectors. The raiser blocks are standard on a Vauxhall Z20NET or an older Saab B207 rail. smiley said the insulators alone lift the rail by about half a centimetre.
- Making your own. nicollow said he had access to workshop facilities and would make something up. smiley asked him to measure the exact height difference so others could copy it, and Exmantaa said no measurements were available, that the injector is at an angle so you need height plus an offset ("slot the rail a bit"), and that from memory only a few millimetres were needed. Exmantaa also said he wasn't sure the alloy blocks made for the plastic insulators could be modified for the small offset without them. The thread ends before the result.
- A different answer. fezzasus said the Bosch injectors he used come with an adaptor, the black section above the tip, which alone adapts them to LSJ heads, and that he believed this makes the grey insulator and the rail spacers unnecessary. His photo is below. larres said the correct adapters can be bought from a specialist, and he bought the purple ones for black Bosch injectors. It isn't clear that fezzasus and nicollow had the same injector, and nicollow's rail still stood proud with adapters fitted.
- Spares. The Batman offered rail spacers and grey insulators in 2018, and in 2013 had GM spacers for the Siemens injectors and planned to have copies made by Pro Alloy for a group buy. These offers are old.
Swapping to a Z20NET rail
- smiley swapped to a Z20NET rail, which already has the raiser blocks. It comes with a 3.0 bar regulator, though, where the Z22SE one is 3.8 bar.
- Exmantaa said if you swap rails you must change the pressure regulator to the Z22SE version, or change the fuel mapping in OBD Tuner for 3.0 bar. Their LSJ ECU builds run 3.0 bar because it is easier to map with the 60 lb injectors.
- smiley said the idea of lower pressure was less hot fuel pumped back to the tank, but he now says "don't bother". See the sizing guide.
Connectors
smiley (2018) said the original plugs (which he called EV6 format) fit the original injectors, the black turbo injectors and the green LSJ injectors, and that all other injectors need your connectors converted to EV1 format. The Batman said the blue VXR injectors use EV1 plugs, which agrees. But Exmantaa said in 2013 that the EV1 connector is "the Bosch (Z20LET/VXR) type", which disagrees with smiley about the black turbo injector. Check your own plugs. NickB787 got an EV1 harness along with his injectors. The part number of a harness or adapter isn't in the threads.
Orientation
jim61 asked whether the EV14s have to point a particular way, since the rail clip doesn't locate them as it does on LSJ injectors. siztenboots replied that the dual spray cone should match the inlet ports. jim61 then asked whether that means the plug has to be in the same position as the original, and the thread doesn't answer. If you are fitting dual-spray injectors, work out which way the spray cones go before you tighten anything.
Buzzing rail and hot starting (2011, unsolved)
An owner had a buzzing noise from the fuel rail area, hard starting when warm, and then hesitation under acceleration with a brief flash of the engine light. He took the rail off and swapped in a set of injectors from another owner, but the buzz stayed. Using the ear-on-a-screwdriver trick he was 99% sure it came from the rail. The thread ends there, with no cause found, so we can't say whether it was the regulator, a sticking injector or something else. See Fuel pump replacement for the pump side.