Replacing or Servicing Fuel Injectors for the Chevrolet VE Caprice
- Document Information
- Information on how to remove and replace fuel injectors on a Chevrolet Caprice (V8 Models)
- Vehicle: Chevrolet Caprice (VE)
- Copyright Owner: Matthew Jones (Matti Jones) (ZerOne)
- Document Visits: 2015
- Created: Wed Oct 23, 2013 3:47 am
- Revised: Wed Oct 23, 2013 3:51 am (Rev 4)
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The following guide provides information on how to remove the fuel rail from the engine,
as well as change one or more fuel injectors.
This guide includes some information on how to relieve some of the fuel pressure by running the engine with the fuel pump relay disconnected,
as well as information on how to diagnose possible fuel injection issues.
This guide has not been written as a definitive guide on how to replace injectors,
rather it is more a collection of helpful suggestions made to myself when I needed to replace a faulty fuel injector on my vehicle.
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Tools Required
10mm Open Ended / Ring Spanner
18mm Open Ended Spanner
9mm Socket or Spanner
Small Ratchet Wrench
Common Parts Required
Injector O-Ring seal kit. (Holden Part# 89017587)
Fuel Injectors (If these are to be replaced)
Rags
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This document was written because my VE Commodore began to misfire one day on the way home from work.
Previous to this problem, I had intermittent missing symptoms when starting the engine on cold mornings.
(In my case, the engine would run very rough, with the instrument cluster displaying an ESP disabled or check engine warning immediately after starting).
Once the engine had warmed up (I.E. after leaving the engine to run in this state for a period of 60 seconds), I would turn off the ignition,
and restart the engine. 90% of the time this was sufficient enough to get the engine firing on all cylinders, and running normally.
On the way home from work one day, the engine permanently developed a misfire.
Using a scan tool, the scan tool reported a P???? error code (Cylinder 4 fuel injector circuit fail).
At least with this error code, I had something to work with in order to repair the problem.
The following diagram may help when dealing with diagnostic trouble codes read via an OBD Scantool or reader.
This image outlines the cylinder numbering used by GM (Holden, Pontiac, Chevrolet, Vauxhall, Buick and Cadillac) for their V8 Engines.
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Now that I had an error code, I could test the fuel injector circuit for the cylinder specified.
The following diagram shows the cylinder numbers used by GM for all of their modern V8 motors.
With the above error code, the fuel injector issue could be one of three possible problems.
1) The Fuel Injector has failed (The coil has burnt out and has gone open or short circuit).
2) The Wiring for the fuel injector could be damaged (I.E. gone open or short circuit)
3) The Fuel Injector plug could be faulty, and may not be making a good connection with the fuel injector.
To conduct any of the above tests, you will need to disconnect the fuel injector wiring plug from the fuel injector.
Disconnecting the Fuel Injector Wiring Connector.
1) Remove the Engine cover.
(This cover simply clips in to place).
2) Using long nose pliers, pull the grey coloured injector wiring plug cover upward and off the fuel injector wiring plug.
3) The fuel injector wiring connectors can be released by pressing down on the wiring connector clip,
and gently pulling the wiring connector upward from the fuel injector.
Testing the Fuel Injector for Open or Short Circuit
Using a multimeter set to measure Ohms, measure the resistance between the two pins on the fuel injector.
If the coil on the fuel injector is good, you should see a resistance somewhere around 12 Ohms.
If the coil has burnt out, you will see a reading of 0 Ohms (Short Circuit), or ~ Ohms (Open Circuit).
If this is the case, the you will need to replace the fuel injector.
Testing the Fuel Injector Wiring.
The holes on the fuel injector wiring connector are very small, and as such it is recommended that you use either very small diameter wiring to insert in to the connector for testing, or use the leg off a resistor.
This test should also help you identify if the fuel injector wiring connector may also be causing you problems.
1) Turn the ignition switch to the ON position. (Do not start the car)
2) Using a small diameter wire (or resistor leg), insert the wire/leg in to one side of the fuel injector wiring plug,
and measure for +12V DC using a multimeter.
3) If you cannot detect +12V DC, move to the other pin on the injector wiring connector, and test again for +12V
4) If the Ignition switch is ON, and you cannot measure +12V, then it is possible that the wiring or wiring connector is faulty.
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1) Remove the fuel pump relay.
This relay is located in the cabin fuse box, located on the passenger side kick panel. (NOTE : When removing the relay take special not of the relays orientation, as it is possible to fit the relay upside down.
(Which may cause damage electrical damage later on).
2) Crank the engine a couple of times, allowing the engine to stall.
(This will release some of the fuel pressure in the fuel lines, as well as consume some of fuel in the fuel rail).
3) Remove the Engine cover.
(This cover simply clips in to place).
4) Using long nose pliers, pull the grey coloured injectoring wiring plug cover upward and off the fuel injector wiring plug.
5) Continue the above steps until you have removed all 8 of the grey injector wiring plug covers.
6) The fuel injector wiring connectors can be released by pressing down on the wiring connector clip,
and gently pulling the wiring connector upward from the fuel injector.
7) Continue the above step untill all 8 fuel injector wiring connectors have been disconnected.
8) Ensure that the fuel injector wiring connectors are placed away from the fuel injectors,
as these may prevent the fuel rail and fuel injectors from being removed as a single assembly later on.
9) Place the heater hoses to the side of the engne, so as they do not get in the way when removing the fuel rail and injectors later on.
10) Using a 10mm Deep socket, remove the four bolts holding the Fuel rail in place.
11) Using a 9mm socket, remove the bolt shown in the image below.
12) Remove the fuel rail ground strapping shown below
13) Lossen the 4 bolts used to secure the fuel rail shields located at the back of the engine.
(Note these bolts do not need to be completely removed, as lossening these bolts will allow you to move these shields around allowing you to more easily remove the fuel rail).
13) Slowly and carefully remove the fuel rail and injectors as a single assembly, from the intake manifold.
To do this, work you way around the fuel rail, incrementally pulling each injector from the manifold.
Be careful not to pull the injectors from the fuel rail, as this will result in fuel spillage.
14) Carefully remove the fuel rail and injector assembly from the engine,
carefully inverting the fuel rail assembly and placing it on the right hand side of the engine.
15) Mop up any spilt fuel from around the intake manifold injector holes,
and inspect these holse to make sure that the lower injector O-Rings or Injector hats have not come off the injector, and remained in the intake manifold.
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1) Using long nose pliers, remove the clip used to secure the fuel injector to the fuel rail
2) With the fuel injector clip removed, gently work the fuel injector away from the fuel rail.
(Note it is highly likely that fuel will leak from the fuel rail once the injector has been removed, so it is highly advisable to have a rag or cloth to mop of any fuel spillages at this point).
3) With the fuel injector removed, you should be left with something like the following.
4) At this point, you can either replace the injector with another unit, or service this injector as required.
5) With your new or serviced injector, you will need to replace the upper and lower O-Rings, as these are single use items.
(If these are not replaced, then it is likely that these will allow fuel to leak once the fuel pump applies fuel pressure when the engine is started).
6) Remove the old upper O-Ring, and fit the new O-Ring to the injector.
7) Place a small quantity of motor oil on the new injector O-Ring.
This will assist in fitting the injector back in to the fuel rail, as well as help provide a seal between the fuel rail and O-Ring once the oil has dried.
8) Gently fit the injector back on to the fuel rail by slowly working the injector in to the fuel rail mounting hole.
(NOTE do not push the injector completely in to the fuel rail, as you will need to align the injector clip later on)
9) Line up the fuel injector so as the wiring plug is back away from you, and that the clip guides on the fuel injector are above the fuel rail.
10) Slide the fuel injector mounting clip over the fuel injector, and adjust the fuel injector and clip to ensure that the clip clips over the fuel rail mounting flange.
11) Align the fuel injector wiring plug so as it is facing towards the outside of the fuel rail.
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When refitting the fuel injectors back in to the engine,
it is highly recommended that the lower O-Ring seals are replaced for each injector,
to prevent possible fuel leakage later on.
1) Remove the lower O-Ring seals from all 8 Injectors. (These are coloured Red for the factory O-Ring kit)
2) Carefully fit the new replacement O-Rings from the Injector O-Ring kit to the bottom of the injectors.
3) Place a small quantity of motor oil on the new injector O-Ring.
This will assist in fitting the injector back in to the intake manifold, as well as help provide a seal between the manifold and O-Ring once the oil has dried.
4) Carefully align the fuel rail, and injectors up with the intake manifold, taking care not to knock the fuel injectors off from the from rail,
and taking care that the injector wiring loom and heater hoses do not get caught up with the fuel injectors or fuel rail.
5) Gently slide the injectors in to place on the intake manifold, taking care to evenly press down on the fuel rail so as each injector receives equal pressure, until all injectors are seated in the intake manifold.
6) Inspect each injector that it is sitting correctly inside the intake manifold, and begin fitting the 4 main bolts used to hold the fuel rail in place.
7) Hand tighten the 4 fuel rail bolts sequentially, allowing an equal amount of pressure to be applied to the fuel rail and injectors.
8) Tighten the 4 fuel rail bolts to xxNm
10) Refit the Fuel Pump relay removed previously from the cabin fuse box, taking note that the relay is fitted in its correct orientation.
11) Turn the Ignition switch to the ON position and wait 10 seconds.
12) Turn the Ignition switch to the OFF position and inspect for any fuel leaks around the fuel rail and fuel injectors.
13) Turn the Ignition switch to the ON position and inspect again for any fuel leaks.
14) Turn the Ignition switch to the OFF position.
15) Refit the 8 Fuel Injector wiring connectors.
16) Start the engine (This may take a couple of cranks to prime the fuel lines with fuel), and inspect for any fuel leaks.
17) Check for any error codes such as fuel pump disconnected, or injector circuit errors.
18) If there are no error codes, and no fuel leaks, test drive the vehicle.
19) Tighten the 4 bolts used to secure the fuel rail shields located at the back of the engine.