Product Description
EG / EK Civic & DC Integra D-Series Full Tucked Fuel System (Level 4)
The JBtuned Level 4 D-Series Full Tucked Fuel System replaces the factory chassis fuel plumbing on compatible EG and EK Honda Civics and applicable DC Acura Integras running a Honda D-Series engine.
Level 4 replaces the fuel feed and return from the tank to the engine and back with complete aftermarket AN fuel plumbing while retaining the clean engine-bay layout of the JBtuned D-Series tuck system.
Choose a 6AN or 8AN main fuel feed, a dedicated 6AN return and either JBtuned 250 Series rubber-core hose for pump gasoline or JBtuned 350 Series PTFE hose for broader fuel compatibility.
This is Level 4 in the JBtuned D-Series fuel-system lineup: “I want to replace everything.”
Level 4 at a Glance
- Primary Fitment: 1992-1995 Honda Civic EG and 1996-2000 Honda Civic EK with D-Series engine
- Additional Fitment: Applicable 1994-2001 Acura Integra DC chassis with D-Series swap
- Engine: Compatible Honda D-Series engines including D15 and D16 combinations
- System Type: Complete tank-to-engine-and-back feed-and-return fuel system
- Factory Chassis Fuel Lines: Replaced
- OEM Firewall Fuel Filter: Removed from the fuel-system layout
- Feed Line: 6AN or 8AN
- Return Line: 6AN
- Fuel Hose: JBtuned 250 Series rubber-core or 350 Series PTFE
- Fuel Compatibility: Depends on selected hose series
- Fuel Filter: Large-body inline filter included
- Fuel Rail: Compatible OEM Honda or aftermarket D-Series fuel rail
- Fuel Pressure Regulator: Configuration depends on selected rail and hose series
- Fuel Pump: Not included unless selected
What Comes With the Base Level 4 System
- Complete aftermarket fuel-feed plumbing from the fuel tank to the engine bay in the selected 6AN or 8AN size
- Complete 6AN return plumbing from the engine bay back to the fuel tank
- Pre-assembled JBtuned fuel-line assemblies configured for the selected chassis and fuel-system options
- Large-body inline fuel filter
- Serviceable 6-micron stainless-steel filter element
- Fuel-rail connection components for the selected configuration
- Fuel-pressure-regulator connection components for the selected configuration
- Required AN connection hardware for the configured base fuel system
Exact line and connection configurations vary depending on the chassis, hose series, feed-line size, fuel rail, fuel pressure regulator and options selected when ordering.
The fuel rail is not included. The fuel pump and fuel pressure regulator are not included unless selected or purchased separately.
What Level 4 Changes
Level 4 replaces the factory chassis feed and return plumbing with dedicated aftermarket fuel lines running from the fuel tank to the engine bay and back.
The OEM firewall-mounted fuel-filter arrangement is also removed from the fuel-system layout and replaced with the included large-body inline filter.
This gives the vehicle a complete aftermarket fuel system without relying on the original Honda chassis fuel lines.
Feed-line size, hose material and fuel type are configuration choices within Level 4 rather than separate fuel-system levels.
6AN or 8AN Feed With 6AN Return
The D-Series Level 4 system allows the main fuel-feed size to be selected according to the requirements of the build.
- 6AN Feed / 6AN Return
- 8AN Feed / 6AN Return
The return remains 6AN with either feed configuration.
Fuel-pump capability, injector demand, fuel type, operating pressure and expected fuel demand should all be considered when selecting feed-line size.
A larger fuel line does not by itself increase the output capability of the fuel pump or the rest of the fuel system.
Choose the Correct Fuel Hose
Level 4 is available with two JBtuned fuel-hose families. The Level determines the fuel-system architecture; the hose series determines fuel compatibility.
250 Series Rubber-Core Hose - Pump Gasoline: Choose JBtuned 250 Series for conventional pump-gasoline applications. 250 Series hose is not intended for continuous or full-time E85 use.
350 Series PTFE Hose - Pump Gas / E85 / Compatible Race Fuels: Choose JBtuned 350 Series PTFE for pump gasoline, E85 / ethanol and compatible race fuels, or for a gasoline build where broader future fuel compatibility is desired.
Choosing 350 Series PTFE does not mean the vehicle has to run E85.
E85 Compatibility Is Not the Same as Flex-Fuel Sensor Integration
Selecting the 350 Series PTFE configuration makes the fuel plumbing suitable for pump gasoline, E85 and compatible race fuels.
That does not by itself make the vehicle a sensor-based flex-fuel system.
An ethanol-content sensor can provide real-time fuel-composition information to a compatible ECU for a sensor-based flex-fuel strategy, but sensor wiring, engine-management compatibility, ECU configuration and tuning are separate from the fuel-system plumbing.
If you specifically want the complete Level 4 fuel-system layout configured around ethanol-content-sensor installation, choose the JBtuned D-Series Complete Flex-Fuel System.
You do not need the sensor-specific system simply because the vehicle will run E85. This standard Level 4 system can also support E85 when configured with JBtuned 350 Series PTFE hose.
Not sure which configuration is appropriate? Read our guide to E85, PTFE fuel lines and flex-fuel systems.
Large-Body Inline Fuel Filter
The D-Series Level 4 Full Tucked Fuel System includes a large-body inline fuel filter with a serviceable 6-micron stainless-steel element.
The filter replaces the original Honda firewall-mounted fuel-filter arrangement as part of the complete aftermarket fuel system.
OEM or Aftermarket D-Series Fuel Rail
The D-Series Level 4 system can be configured for the factory Honda D-Series fuel rail or compatible aftermarket D-Series fuel rails.
Select the fuel rail installed on the engine when ordering so JBtuned can configure the appropriate fuel-system connections.
If your fuel rail is not represented in the available options, contact JBtuned before ordering.
Fuel Pressure Regulator Configuration
Fuel pressure regulator requirements depend on the fuel rail and hose series selected.
250 Series Configuration: Compatible OEM-style and aftermarket rail-mounted regulator arrangements can be used where appropriate for the selected fuel rail and regulator setup.
350 Series PTFE Configuration: The return side requires a regulator with an appropriate AN-compatible return connection.
The factory Honda fuel rail may still be retained in compatible configurations, but the OEM regulator's hose-barb return connection is not appropriate for the PTFE return-line configuration.
Customers retaining a compatible OEM Honda fuel rail with the 350 Series PTFE system can consider the AEM Honda / Acura Adjustable Fuel Pressure Regulator for an AN-compatible regulator connection.
If your fuel rail or regulator configuration is not represented in the available options, contact JBtuned before ordering.
Rail-to-Regulator Connection
Depending on the fuel rail and regulator combination installed on the vehicle, an additional rail-to-regulator connection may be required.
Select the appropriate Rail-to-Regulator Connection option when ordering so the fuel system can be configured for the components being used.
If you are unsure which option applies to your fuel rail and regulator combination, contact JBtuned before ordering.
Clean Tucked Engine-Bay Layout
The Level 4 system retains the cleaner engine-bay layout of the JBtuned D-Series Level 3 Fuel Line Tuck Kit while extending the aftermarket fuel plumbing all the way back to the tank.
A tucked fuel system does not mean every fuel hose disappears from view. The goal is to remove unnecessary factory fuel-system clutter and create a cleaner, organized AN-style layout that remains practical to service.
Final routing depends on the fuel rail, regulator, intake manifold, header, turbo system and other components installed in the vehicle.
Vehicle & Engine Fitment
- 1992-1995 Honda Civic EG with D-Series engine
- 1996-2000 Honda Civic EK with D-Series engine
- Applicable 1994-2001 Acura Integra DC chassis with D-Series swap
- D15 engine combinations
- D16 engine combinations
- SOHC VTEC D-Series combinations
- Non-VTEC D-Series combinations
- Other compatible Honda D-Series engines
Final fitment depends on the chassis, fuel rail, fuel pressure regulator, fuel-pump hanger and other components installed on the vehicle.
If your combination is unusual or your components are not represented in the available options, contact JBtuned before ordering.
Ordering Options
Vehicle / Chassis: Select the vehicle receiving the complete D-Series fuel system.
Fuel Hose Series: Choose 250 Series rubber-core hose for conventional pump gasoline or 350 Series PTFE for pump gasoline, E85 / ethanol and compatible race fuels.
Feed Line Size: Choose either a 6AN or 8AN main fuel feed. The return remains 6AN.
Fuel Rail: Select the OEM Honda or aftermarket D-Series fuel rail installed on the engine. Different rails require different connection configurations.
Fuel Pressure Regulator: Select the regulator configuration being used with the vehicle. The selected fuel rail, regulator and hose series determine the appropriate return-side connections.
Rail-to-Regulator Connection: Select the appropriate option based on the fuel rail and regulator installed on the engine.
Fuel Pump Hanger Upgrade: Select the appropriate JBtuned hanger upgrade if the factory sending unit has not already been configured for the complete aftermarket feed-and-return system and fuel pump being used.
Under-Car Fuel Line Brackets: Add the JBtuned Fuel & Brake Line Holder Brackets for secure mounting of compatible aftermarket feed and return lines underneath the vehicle.
Fuel Pump Hanger & Fuel Pump
A complete Level 4 system requires appropriate aftermarket feed-and-return connections at the fuel tank.
If the factory sending unit has not already been configured for the aftermarket AN plumbing and fuel pump being used, see the JBtuned Civic / Integra OEM Fuel Pump Hanger Upgrade Kit.
The hanger configuration varies according to the fuel pump being used, so select the appropriate fuel-pump configuration when ordering.
Fuel-pump requirements depend on the engine combination, fuel being used, injector demand, operating pressure and expected fuel demand.
If you need a fuel pump, shop JBtuned fuel pumps.
Under-Car Fuel-Line Support
Because Level 4 replaces the factory chassis fuel plumbing, the new feed and return lines must be securely supported underneath the vehicle.
For compatible EG, EK and DC chassis, JBtuned offers JBtuned EG EK Civic / DC Integra Fuel & Brake Line Holder Brackets.
These brackets are designed to support compatible aftermarket fuel lines while allowing the factory brake hard lines to remain in place.
Select the bracket configuration that matches the feed and return sizes and hose series used by the system.
Already Have the D-Series Level 3 Fuel Line Tuck Kit?
If you already own the JBtuned D-Series Level 3 Fuel Line Tuck Kit, you may not need to purchase the complete Level 4 system again.
The Level 3 system already provides the engine-bay feed-and-return plumbing, removes the OEM firewall filter and incorporates the compact inline filter while retaining the factory chassis fuel lines.
If you later want to replace the remaining factory chassis feed and return plumbing, the JBtuned Fuel System Extension Kit continues the compatible Level 3 system back to the fuel tank.
This allows you to retain the engine-bay portion of the JBtuned system you already purchased while replacing the remaining chassis plumbing.
Standard Level 4 or Flex-Fuel Level 4?
Both D-Series complete systems replace the factory chassis fuel plumbing from the fuel tank to the engine and back.
D-Series Full Tucked Fuel System: Choose this system when you want the complete Level 4 fuel-system architecture. Select 250 Series for conventional pump gasoline or 350 Series PTFE for pump gasoline, E85 and compatible race fuels. You are here.
D-Series Complete Flex-Fuel System: Choose this version when you want the same complete Level 4 architecture built exclusively with 350 Series PTFE and specifically configured around ethanol-content-sensor integration.
The difference is sensor integration, not whether the standard Level 4 system can carry E85.
View the D-Series Complete Flex-Fuel System
JBtuned D-Series Fuel-System Levels
- Level 1 - “I Just Need the Feed Line”: Retains the OEM firewall filter, factory chassis plumbing and existing return-side system while replacing or upgrading the filter-to-rail fuel-feed line.
- Level 3 - “I Want It Cleaner / Tucked”: Retains the factory chassis feed and return lines, removes the OEM firewall filter, adds a compact inline filter and upgrades the engine-bay feed and return plumbing.
- Level 4 - “I Want to Replace Everything”: Replaces the complete factory chassis feed and return plumbing from the fuel tank to the engine and back, with feed size and hose series selected to match the build. You are here.
Which D-Series Fuel System Should I Choose?
Choose Level 1 if you only want to replace or upgrade the filter-to-rail fuel-feed line while retaining the OEM firewall filter and existing chassis plumbing.
Choose Level 3 if you want to remove the large OEM firewall filter, add a compact inline filter and use a cleaner engine-bay feed-and-return layout while retaining the factory chassis fuel lines.
Choose Level 4 if you want to replace the factory chassis fuel plumbing with a complete aftermarket feed-and-return system from the fuel tank to the engine and back.
Installation Notes
- This is a complete aftermarket fuel-system installation that replaces the factory chassis fuel plumbing from the fuel tank to the engine and back.
- Installation requires access to the fuel tank, underbody fuel-line routing, fuel-pump hanger, engine-bay fuel system, fuel rail and regulator connections.
- All fuel lines must be securely routed and protected from exhaust heat, moving components, sharp edges and potential abrasion.
- Turbocharged and other high-heat applications require additional attention to fuel-line clearance and thermal protection.
- After installation, pressurize the fuel system and carefully inspect every connection for leaks before starting or operating the vehicle.
Changes to fuel pressure, fuel pump, injectors, fuel type or other fuel-system components may require appropriate ECU configuration and tuning.
Professional installation is recommended if you are unfamiliar with complete aftermarket fuel systems or AN plumbing.
For off-road use only.
Questions About Your D-Series Fuel System?
If you are unsure whether the standard D-Series Level 4 Full Tucked Fuel System or the Complete Flex-Fuel version is right for your build, contact JBtuned with your vehicle, year, D-Series engine, fuel rail, fuel pressure regulator, fuel pump, fuel being used and engine-management setup.
