Fuel injectors keep leaking...lube oil myth?

[Killer50stang]

I'm currently trying to figure out what I'm doing wrong. I just replaced my lower intake and pulled the injectors, replaced all the o-rings. I put everything back together and it keep leaking gas from the rail. I have an o-ring on top of the injector and one on bottom. I've even replaced the clamps with new ones to be sure they are clamped right and it still leaks. When I lubed them I used oil and a guy told me to never use oil because it will expand the o-ring and ruin it. Is this true? I've never had the problem before. Another thing is, it might be fine for a couple of days and then start leaking again...it's starting to make me mad. Another guy said there should be a plastic cup shaped piece at the bottom of the injector. I have no idea what he's talking about and I don't have that either. Any ideas what I might be doing wrong?

Jason

 

[jrichker]

The fuel injector seals are oil resistant. Gasoline and oil are both petrolem based products and any O ring would need to be resistant to both.

O ring arrangement:
Top of injector gets 1 O ring
Bottom of injector gets one plastic spacer washer, one O ring and a pintle cap that snaps on the end of the injector to hold the O ring and spacer in place.


See the diagram for a visual explanation:


Diagram courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif


Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts. Cost is about $2.74 per kit.. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

Most of the links above have store locators for find a store in your area.

Use motor oil on the O rings when you re-assemble them & everything will slide into place. The gasoline will wash away any excess oil that gets in the wrong places and it will burn up in the combustion chamber.

The pintle caps fit either injectors with a pin sticking out the injector end or 4 with more tiny holes in the injector end
The pintle caps hold the O ring in place and keep it from sliding off and into the manifold. If the correct pintle caps are used, they do not have any effect on the injector spray pattern.


Heating the pintle caps in boiling water makes it much easier to install them.

 

[Killer50stang]

The fuel injector seals are oil resistant. Gasoline and oil are both petrolem based products and any O ring would need to be resistant to both.

O ring arrangement:
Top of injector gets 1 O ring
Bottom of injector gets one plastic spacer washer, one O ring and a pintle cap that snaps on the end of the injector to hold the O ring and spacer in place.


See the diagram for a visual explanation:


Diagram courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif


Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts. Cost is about $2.74 per kit.. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

Most of the links above have store locators for find a store in your area.

Use motor oil on the O rings when you re-assemble them & everything will slide into place. The gasoline will wash away any excess oil that gets in the wrong places and it will burn up in the combustion chamber.

The pintle caps fit either injectors with a pin sticking out the injector end or 4 with more tiny holes in the injector end
The pintle caps hold the O ring in place and keep it from sliding off and into the manifold. If the correct pintle caps are used, they do not have any effect on the injector spray pattern.


Heating the pintle caps in boiling water makes it much easier to install them.

Where is the pintle cap located? I have the spacer and oring on the bottom. I don't see where this cap might go.

Jason

 

[go4it]

From post above.

Bottom of injector gets one plastic spacer washer, one O ring and a pintle cap that snaps on the end of the injector to hold the O ring and spacer in place.

 

[jrichker]

Where is the pintle cap located? I have the spacer and oring on the bottom. I don't see where this cap might go.

Jason

 

[302RollinHard]

hey may have the lucas/delphi type of injectors that don't have pintle caps.

 

[Killer50stang]

Do all cars use the pintle caps? I have the same problem on my 98 venture van.

Jason