1999 GMC Suburban Logo
Posted on Dec 18, 2010
Answered by a Fixya Expert

Trustworthy Expert Solutions

At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.

View Our Top Experts

Antifreeze leaks from intake ,need to know how to remove upper intake , fuel injectors are my bigest problem ,need to know how to remove them and proper tourque for bolts?

  • Anonymous Mar 14, 2014

    why is fuel leaking out through upper intake

×

1 Answer

William Robinson

Level 3:

An expert who has achieved level 3 by getting 1000 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Genius:

An expert who has answered 1,000 questions.

  • Master 1,547 Answers
  • Posted on Dec 18, 2010
William Robinson
Master
Level 3:

An expert who has achieved level 3 by getting 1000 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Genius:

An expert who has answered 1,000 questions.

Joined: Nov 29, 2010
Answers
1547
Questions
0
Helped
502096
Points
4729

I just completed this task. I would suggest not removing the upper intake unless you just can't get around it. It is not hard, just time consuming. You will have to move most of your accesories out of the way (alternator and A/C, remove the upper fan shroud and the power steering pulley along with the A/C mounting bracket) If you are having the common intake coolant leak problem, I suggest you also spring for a new set of intake bolts. Be careful how tight you torque evrything, remember its aluminum.


After disassembly make sure evrything is super clean, if you scrape the intake be careful not to scratch or gouge it.
When you go back together you will need to be very careful of how you position the intake, the front and rear seals are RTV Black and you must clear some obstacles near the rear of the engine so you can place the intake square and straight down on the block.



  • William Robinson
    William Robinson Dec 18, 2010





      Take a picture of the assembled engine or carefully make
      notes of how and where everything attaches. Remove the air intake system
      and any hoses, mounts, wires or other parts that are in the way of the
      car injector railing.






      2


      Locate the bolts that hold the injector retaining rail in
      place and remove them. Pull out the rail to gain access to the
      injectors. Not all cars have an injector retaining rail.






      3


      Put on your goggles and pull out the first injector. The
      pressure in the system will make a small amount of gasoline squirt out
      with considerable force. If your injectors require a special removal
      tool you can purchase these at a dealership or local auto parts store.






      4


      Look for the old seal and make sure pieces are not stuck in the seat. Use a pick or small screwdriver to get any remnants out.






      5


      Prepare the new fuel injector by removing any caps and
      lubricating the seal with a small amount of motor oil. Move the new
      injector to the car and place it next to the fuel line on a clean rag.






      6


      Attach the new fuel injector and pay careful attention to the manufacturer's recommended torque.






      7


      Connect any hoses, wires and other parts, taking time to
      clean off excess grease and dirt along the way. If you forgot where
      something connects look at your notes or the picture you took.



  • William Robinson
    William Robinson Dec 18, 2010

    Before you begin the process of replacing a fuel injector or fuel injection rail, you need to think about safety. Always keep fire safety in mind when you are working with fuel. You also need to be sure you are wearing eye protection. Even if you've released the pressure in the fuel injection system, there could be some fuel flying when you start disconnecting high pressure lines and removing injectors.First, disconnect the main fuel line at the end of the rail. There may be an additional line at the other end, so remove that one, too. The fuel rail is help in place by screws or bolts, depending on your car's setup. Remove these screws or bolts. If your wiring travels over the top of the rail, see the next step to disconnect the wiring first. With everything disconnected from the rail, pull it away from the fuel injectors. Most fuel rails are just pressed onto the injector tops, once you've removed the hold down screws or bolts it should pull away, with a little oomph.If your car uses a fuel rail to deliver fuel to the injectors, you removed it in the previous step. If you don't have a fuel rail, you'll need to remove a fuel line from the top of each injector. It's just as easy to remove, just do it carefully.

    With the fuel delivery out of the way, you're ready to disconnect the fuel injectors. Each injector will have a plug at the top (or on the side near the top) that connects to the wiring harness. Most fuel injector wiring plugs are held securely in place by a springy wire (see pic). To remove this wire, just insert a flat head screwdriver in the space between the spring and the plug and pry it carefully away. It will come out easily. Don't lose it!With all of the other stuff out of the way, you're ready to yank the injector. Unfortunately, many people really do try to yank them out. Remember, your fuel injectors sit right in the middle of the delicate are of the engine, so any piece you break off might fall in, and this equals big pain in your fanny.

    The safest way to remove a fuel injector is to use a fuel injector puller. There are other ways to remove fuel injectors, but if you aren't careful you could damage some expensive fuel injection components. Besides, the injector puller makes it so easy, just slide it underneath the lip in the injector housing and pop the injector out.

    Your fuel injector goes into what amounts to a hole in the intake manifold (or your head if you're lucky). When you remove the injector, you leave this hole open. Be very careful to keep anything from falling in. This can be a real chore to fix.

    In the immortal words of every auto repair tutorial, installation is the reverse of removal! You'll need to lubricate the new injector seals before they go in, and remember to go easy, don't force anything in.

×

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

Rough idle and misfire

These trucks have a spider injector and all depending on the year it may have one central injector or 6 and then popets, these are lines that run to each injector, you will need to make sure the fuel pressure is good, low pressure will cause problems i think it is 62 psi key on engine off, and the other problem is the fuel lines going into the rear of the intake to feed the injector leak inside and cause rough idle and misfire, this is for the older one. the newwer trucks have the fuel lines external and you will see them on the top of the injector housing.

A good way to tell if the line is leaking , o and also the fuel regulator inside the plenium also leaks causing the same type of problem, to test you will need a fuel pressure gauge , hook it up ,turn key on and pressure will go up then turn key off and if pressure drops then you have a leak, could be fuel pump check valve but may be line or regulator, if you remove the throttle body and with a pen light look inside intake for leakage.or remove upper intake and do the same thing, better view this way.
0helpful
1answer

I need to see a coolant system hose that leaks does the intake have to be removed

Yes there are cooling system hoses under the intake, here are instructions to remove the intake.

Instructions
  1. Remove the Intake Manifold
    • 1Drain the cooling system and relieve the pressure in the fuel system. Disconnect the negative battery cable, the air intake duct, the IAC valve connectors, the throttle position sensor and switch connectors, and the EGR solenoid valve.
    • 2Pull the EVAP canister vacuum and purge hoses, the vacuum hoses from the EVAP, the brake cylinder, pressure regulator and EGR tube. Tag and disconnect the spark plug wires. Remove the distributor cap.
    • 3. Take out the three left bank injector connectors, the thermal transmitter, the ground harness, breather pipe and the upper manifold. Disconnect the fuel feed and return lines and plug them with golf tees to prevent fuel spillage.
    • 4Locate the right injector harness connectors and disconnect them as well as the fuel rail and injectors. Remove the coolant temperature switch harness connector and the water hose from the thermostat.
    • 5Loose the bolts on the lower manifold in sequence. Remove the bolts and left the intake manifold from the engine. Remove the gasket and discard it.
    • 6Clean the mating surfaces by scraping the old gasket material and carbon deposits. Clean the surfaces with solvent and inspect them for damage.
    Install the Intake Manifold
    • 7Put a new gasket in place and install the lower intake manifold to the engine. Tighten the bolts in sequence as follows: first pass-35 inch pounds; second pass-78 inch pounds and third pass 70 to 84 inch pounds.
    • 8Connect the ECT sensor connector, the fuel supply manifold and the right bank injector connectors. Connect the fuel lines and then install the upper intake manifold. Put the breather pipe in position.
    • 9Install the intake manifold ground cable, the thermal transmitter, the left bank injector connectors and the distributor. Reconnect the spark plug wires.
    • 10Continue reconnecting all the components, reversing the order in which they were removed. Connect the negative battery cable to the terminal. Refill the cooling system with the appropriate coolant.
    • 11Start the engine. Check for fuel or vacuum leaks.
0helpful
1answer

1996 4.3 vortec S10. Cranks wont start when engine/ outside temp is cold. Have used starting fluid,will start and run rest of day. Fuel pmp is cycling relay is working,needed a tune up I replaced all...

The plenum shouldn't be damp with gas. Is it a throttle body fuel injection system?

Could be a leaky injector.

Fuel Meter Body & Fuel Injectors (4.3L Engine) Removal & Installation 1995-2002 Models (RPO L35) To Remove:
4.3L (RPO L35) Fuel meter body assembly gm_trk_sil15_02-04_43_fuel_metr_body_assy.gif

  1. Before servicing the vehicle, refer to the Cautions and Warnings in the beginning of this section
  2. Remove or disconnect the following:
    • Upper intake manifold (See: Upper Intake Manifold)
    • Fuel meter body
    • Injector retainer lock nuts (J) and retainer (K)
    NOTE: Use care in removing the fuel injectors to prevent damage to the electrical connector terminals. The fuel injector is serviced as a complete assembly only. Also since the injectors are electrical compartments, these injectors should not be immersed in any type of liquid solvent or cleaner as damage may occur. Fuel injector cleaning is not recommended.
  3. While pulling the poppet nozzle tube downward, push with a small tip punch down between the injector terminals until the injector is removed
To Install:
4.3L (RPO L35) Fuel meter body assembly gm_trk_sil15_02-04_43_fuel_metr_body_assy.gif

Note: When ordering new fuel injectors, be sure to order the correct injector for the application being serviced.
  1. Lubricate the new injector O-ring seals with clean engine oil.
  2. Install or connect the following:
    • Fuel injector (L) into the fuel meter body injector socket
    • Retainer (K) and injector retainer lock nuts (J) and tighten the nuts
      1. Torque to: 27 inch lbs. (3 Nm)
    • Fuel meter body
    • Upper intake manifold (See: Upper Intake Manifold)
  3. Test drive the vehicle to confirm the repairs.
1993-2005 Models (RPO LU3) To Remove:
4.3L (RPO LU3) Fuel meter body assembly gm_trk_sil15_02-04_43_rpolu3_fuel_metr_body_assy.gif

  1. Before servicing the vehicle, refer to the Cautions and Warnings in the beginning of this section.
  2. Remove or disconnect the following:
    • Upper intake manifold (See: Upper Intake Manifold)
    • Fuel meter body
    • Injector retainer lock nuts (J) and retainer (K)
    NOTE: Use care in removing the fuel injectors to prevent damage to the electrical connector terminals. The fuel injector is serviced as a complete assembly only. Also since the injectors are electrical compartments, these injectors should not be immersed in any type of liquid solvent or cleaner as damage may occur. Fuel injector cleaning is not recommended.
  3. While pulling the fuel injector downward, push with a small tip punch down between the injector terminals until the injector is removed
To Install:
Note: When ordering new fuel injectors, be sure to order the correct injector for the application being serviced.
  1. Lubricate the NEW injector O-ring seals with clean engine oil
  2. Install or connect the following:
    • Fuel injector (L) into the fuel meter body injector socket
    • Retainer (K) and the injector retainer lock nuts (J) and tighten the nuts
      1. Torque to: 27 inch lbs. (3 Nm)
    • Fuel meter body
    • Upper intake manifold (See: Upper Intake Manifold)
  3. Test drive the vehicle to confirm the repairs
0helpful
1answer

Gas line leaking by engine how do repair that?

Where is it leaking? If its at the fuel rail fuel pressure regulator you may need a new regulator if leaking on the metal part. If its leaking at the rail side its just the "O" ring. Relieve fuel pressure(push in valve under plastic cap right side beside alternator on rail. Remove the torx screw holding regulator bracket. Pry out and replace "O" ring, reassemble. If its not the regulator it may be a fuel injector, you need to remove the fuel rail and replace both the upper and lower injector "O" rings. This however needs the intake manifold removed to repair.
0helpful
1answer

1994 camaro 3.4 injector is leaking unbolted the plenum unpluged the wires to the injectors the plenum will not o come off i am afraid of damageing the other injectors or plenum dont know what to do

The lower intake manifold can be leaking antifreeze, The injectors are reconmended to be removed but they can stay in if nessary the lower intake manifold has 8 bolts and the studs that hold the injectors in have to be removed as they hold the upper phelm on too. To gain clearance to do this job the engine has to be raqised and the motor mounts removed and the then the engine lowered with the mounts removed. the engine will now be low enought to get to the rear bolts. The service maniul says to remove the subframe bolts and lower it all but the steering collum has to be disconnected or the rack released from the subframe and this is an area for damage. I lower the motor with the mounts loose. Break lines and ABS conponants are in the repair list if you let the subframe down too far.
3helpful
2answers

When you turn the key on excessive fuel flows into the air intake. its a 1989 6 cylinder 3.1 fuel injected

You could have either an injector that is stuck open or a fuel pressure regulator that has developed a leak. A leaky injector will usually only leak fuel into one cylinder as it is located just above the intake valve in the lower part of the intake while a leaky fuel pressure regulator will leak fuel into the front end of the intake manifold [behind the throttle plates] and the fuel will acuumulate throughout the upper intake plenum. When a fuel pressure regulator develops a leak the fuel that is escaping from it flows through the small 1/8" diameter plastic vacuum line which goes from the top of the regulator to the intake manifold. Even a trace of fuel in this line means the regulator is bad. I've seen both leak items leak but probably replace 10 regulators leak for every one injector. Good luck, hope you find your problem!
2helpful
1answer

#3 CYLINDER IS FULL OF FEUL AND TRUCK WILL NOT START.REMOVED SPARK PLUGS AND GAS POURS ON GROUND WHEN KEY IS TURNED ON FROM #3 CYLINDER PLUG HOLE.

The Vortec engines were notorious for those kind of problems. The problem will be under the upper-intake manifold, and the fuel injector assembly will either have a cracked plastic fuel line running out to one or more of the fuel injectors, or the fuel pressure regulator that is located on the end of the fuel injector assembly is faulty or it has detached from the fuel injector assembly. Either way the lower intake manifold will be flooded with fuel anytime that the fuel pump runs.

There were two types made, the first type had fuel lines that connected to the lower intake manifold, and then from the metal fittings the fuel line turns into plastic and runs inside the lower intake manifold and under the upper-intake manifold where it runs over to the fuel injector assembly, and this type can really flood out an engine when it becomes faulty.

The second type had metal fuel lines running over the upper intake manifold and they connected to the top of the fuel injector assembly, however, under the upper-intake manifold there are still plastic lines to the fuel injectors and also the fuel pressure regulator that could be faulty and cause the engine to severely flood.

The upper-intake manifold is not that difficult to remove, and after you remove the upper-intake manifold then (replace the fuel lines to the fuel injector assembly if it is the second type) turn the ignition to the "Run" position and when the fuel pump runs you should see where the fuel is leaking/spraying from, and it will most likely be a large high pressure leak from a ruptured plastic fuel line.

Let me know if you require any further assistance.
4helpful
2answers

WHERE IS NUMBER 6 FUEL INJECTOR LOCATED

The #6 fuel injector is located with the #6 cylinder and I have added a firing order and cylinder layout diagram that should help you out.


1730e85.gif
0helpful
1answer

1995 4.3 cpi floods at idle

These had a very common problem with the injector assembly inside the intake manifold. They develop leaks around the seals at the base of the injector spider. You can remove the plenum tuning device at the top of the manifold and look in with a flashlight and see how one side of the intake is washed and wet with fuel to confirm this. To fix the problem you'll need to buy a new injector assembly and gaskets for the upper intake assembly as it has to be removed to get at the injectors.f7b3d8e.jpg
2helpful
3answers

Antifreeze leak.

Are you sure? Coolant is at the front of the intake, but not near the injectors. Do you think its leaking from the gasket?
Not finding what you are looking for?

66 views

Ask a Question

Usually answered in minutes!

Top GMC Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6988 Answers

john h

Level 3 Expert

29494 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...