How to clean the fuel strainer

Air filter plugged - Clean air filter

Tank vent faulty - Clean or replace tank vent if necessary

Leak in fuel line between tank and fuel pump - Seal or renew connections and fuel line

Pump diaphragm damaged or fatigued - Fit new pump diaphragm

Main jet bores or ports blocked - Clean bores and ports

Fuel pickup body dirty - Fit new pickup body

Fuel strainers dirty - Clean fuel strainers

Your excellent description provides a very short list of possible culprits, since your vehicle's symptoms all appear during periods of higher fuel demand.

(1) fuel filter - clogged - your description is absolutely classic (especially stumbling upon uphill acceleration) for a fuel filter in need of replacement.
(2) spark plug wire - one or more bad - an engine can muddle along while traveling over level terrain with one cylinder intermittently failing to fire, but try to go uphill (even the slightest grade), and the engine will skip badly and can even stall if asked to accelerate.
(3) in-tank fuel strainer - clogged - same symptoms as clogged fuel filter.

The fuel strainer is a sock-like pre-filter attached to the input side of the in-tank fuel pump.

The troubleshooting section of the 1998 Honda Civic EX manual states:

Priority Action Part Type Cause
1 Inspect Throttle Position Sensor - Faulty or Incorrectly Connected Throttle Position Sensor.
2 Inspect Mass Air Flow Sensor - Damaged, Loose, or Faulty Mass Air Flow Sensor or Circuit.
3 Inspect Choke - Stuck or Improperly Functioning Choke.
4 Inspect Air Cleaner Tempature Sensor - Damaged or Faulty Air Cleaner Tempature Sensor.
5 Inspect Fuel Filter - Clogged or Dirty Fuel Filter.
6 Inspect PCV Valve - Plugged or Damaged PCV Valve.
7 Inspect Carburetor - Worn, Faulty or Damaged Carburetor.
8 Inspect Fuel Injector - Dirty or Worn Fuel Injectors.
9 Inspect Hose (PCV) - Clogged or Collapsed PCV Hoses.
10 Inspect Fuel Pump - Faulty Fuel Pump.
11 Inspect Fuel Pump - Low Fuel Pressure.

Here's a YouTube video describing hoe to replace a fuel filter on a 2000 Honda Civic (the closest I could find for your 1998).

the strainer is press fit to the bottom of the fuel pump. Take a screw driver and pry the metal part of the strainer off of the plastic part of the pump. Once you see the new strainer you will see what I am talking about.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

The fuel strainer is on the petcock and is up inside the tank. What does the inside of the carburetor look like? If the plastic strainer on the petcock is gummed up, the carburetor will be as well unless it was drained before it was allowed to sit up.

Good Luck
steve

There is no prime of the carb, fuel gravity feeds. So, either you have a jammed float valve or restricted strainer in the fuel tank.

Need to know the size of the engine but this is a picture of what it is....


Posting the rest of the directions for you:



Illustrating fuel pump and sending unit sensor (3) on 2000-2004 4.8L, 5.3L, 6.0L Engines

Removal & Installation

1. Before servicing the vehicle, refer to the Precautions section.
   
2. Remove or disconnect the following:
   
   • Negative battery cable
     
3. Relieve the fuel system pressure.
   
4. Drain the fuel tank.
   
5. Remove or disconnect the following:
   
   • Fuel tank
     
   
   WARNING Do not handle the fuel sender assembly by the fuel pipes. The amount of leverage generated by handling the fuel pipes could damage tool Joints.
   
   
6. Disconnect the fuel and evaporative emission (EVAP) lines from the fuel tank module.
   

• Fuel sender assembly retaining ring using a fuel tank sending unit wrench. Remove the fuel sender assembly and the seal. Discard the seal.
  
• Note the position of the fuel strainer on the fuel sender. Support the fuel sender assembly with one hand and grasp the strainer with the other hand. Pull the strainer off the fuel sender. Discard the strainer after inspection. Inspect the strainer. Replace a contaminated strainer and clean the fuel tank.
  
• Fuel pump electrical connector
  
• Electrical connector retaining clip from the fuel level sensor
  
• Sensor electrical connector from under the fuel sender cover
  
• Fuel level sensor retaining clip
  

Squeeze the locking tangs and remove the fuel level sensor.

Remove the fuel pressure sensor.

To install:

1. Install or connect the following:
   
   • Fuel pressure sensor
     
   • Fuel level sensor
     
   • Sensor retaining clip
     
   • Electrical connector to the fuel level sensor
     
   • Electrical connector retaining clip to the fuel level sensor
     
   • Fuel pump electrical connector
     
   
   NOTE Always install a new fuel strainer when replacing the fuel tank fuel pump module.
   
   
   • New fuel strainer in the same position as noted during disassembly. Push the strainer on the bottom of the fuel sender until the strainer is fully seated.
     
   • New seal on the fuel tank
     
   
   NOTE The fuel pump strainer must be in a horizontal position when the fuel sender is installed in the tank. When installing the fuel sender assembly, assure that the fuel pump strainer does not block full travel of the float arm.
   
   
   • Fuel sender assembly into the fuel tank
     
   • Fuel sender assembly retaining ring
     
   • Fuel tank. Install the fuel tank strap attaching bolts. Tighten the bolts to 30 ft. lbs. (40 Nm).
     
2. Refill the fuel tank. Install the fuel filler cap. Connect the negative battery cable.
   
3. Turn the ignition ON for 2 seconds.
   
4. Turn the ignition OFF for 10 seconds.
   
5. Turn the ignition ON.
   
6. Inspect for fuel leaks.
   

Sound like the needle and seat are dirty. Also check the fuel strainer / filter for debris. Usually if the needle and seat are dirty so is the filter / strainer & bowl.

Needle and seat item(s) 24 and 24 original factory Parts manual under carb. at the dealer:

(called float valve in description)

Sounds like the float valve is either not closing or is dirty and not allowing carb to fill to the proper level. i.e causes fuel starvation AND carb over filling intermittently. You can clean the needle and still have a bad seat for the needle.

Find and replace or clean the fuel filter also. If your carb has a manifold and nut on the side of it for the fuel manifold remove the nut (actually a bolt type thing) and clean the strainer inside the manifold.

Thanks for using FixYa!

Kelly

First...this is where the pump is (gas tank) on the engines listed:



Illustrating fuel pump and sending unit sensor (3) on 1999-2005 4.8L, 5.3L, 6.0L Engines


Removal & Installation

1. Before servicing the vehicle, refer to the Precautions section.
   
2. Remove or disconnect the following:
   
   • Negative battery cable
     
3. Relieve the fuel system pressure.
   
4. Drain the fuel tank.
   
5. Remove or disconnect the following:
   
   • Fuel tank
     

WARNING Do not handle the fuel sender assembly by the fuel pipes. The amount of leverage generated by handling the fuel pipes could damage the joints.

• Fuel sender assembly retaining ring using a fuel tank sending unit wrench. Remove the fuel sender assembly and the seal. Discard the seal.
  

Note the position of the fuel strainer on the fuel sender. Support the fuel sender assembly with one hand and grasp the strainer with the other hand. Pull the strainer off the fuel sender. Discard the strainer after inspection. Inspect the strainer. Replace a contaminated strainer and clean the fuel tank.

• Fuel pump electrical connector
  
• Electrical connector retaining clip from the fuel level sensor
  
• Sensor electrical connector from under the fuel sender cover
  
• Fuel level sensor retaining clip
  

Squeeze the locking tangs and remove the fuel level sensor.

Remove the fuel pressure sensor.

To install:

1. Install or connect the following:
   
   • Fuel pressure sensor
     
   • Fuel level sensor
     
   • Sensor retaining clip
     
   • Electrical connector to the fuel level sensor
     
   • Electrical connector retaining clip to the fuel level sensor
     
   • Fuel pump electrical connector
     
   NOTE Always install a new fuel strainer when replacing the fuel tank fuel pump module.
   
   
   • New fuel strainer in the same position as noted during disassembly. Push the strainer on the bottom of the fuel sender until the strainer is fully seated.
     
   • New seal on the fuel tank
     
   NOTE The fuel pump strainer must be in a horizontal position when the fuel sender is installed in the tank. When installing the fuel sender assembly, assure that the fuel pump strainer does not block full travel of the float arm.
   
   
   • Fuel sender assembly into the fuel tank
     
   • Fuel sender assembly retaining ring
     
   • Fuel tank. Install the fuel tank strap attaching bolts. Tighten the bolts to 30 ft. lbs. (40 Nm).
     
2. Refill the fuel tank. Install the fuel filler cap. Connect the negative battery cable.
   
3. Turn the ignition ON for 2 seconds.
   
4. Turn the ignition OFF for 10 seconds.
   
5. Turn the ignition ON.
   
6. Inspect for fuel leaks
   

According to the factory service manual, you should drop the tank, there are pictures and diagrams with these in the manual.

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure.
3. Drain the fuel tank. .
4. Remove the fuel tank.
5. Remove the fuel sender assembly.
6. Note the position of the fuel strainer (2) on the fuel sender.
7. Support the fuel sender assembly with one hand and grasp the strainer (2) with the other hand.
8. Pull the strainer off the fuel sender. Discard the strainer after inspection.
9. Inspect the strainer. Replace a contaminated strainer and clean the fuel tank.
10. Disconnect the fuel pump electrical connector (5).
11. Remove the electrical connector retaining clip (6) from the fuel level sensor.
12. Disconnect the sensor electrical connector (7) from under the fuel sender cover.
13. Remove the fuel level sensor retaining clip (4).
14. Squeeze the locking tangs and remove the fuel level sensor (3).
15. Remove the fuel pressure sensor (1).

A good place to get an inexpensive service manual is from Promanuals it's a complete factory manual.

You have float and/or needle and seat problems. Remove the hoses from the air box to each carburetor. Set bike on center stand or block up to get it level--turn on fuel tap and watch for leakage from each carburetor. Turn the fuel tap off. Pop the float bowl off of any that leaked, remove the float and pin--catch the float needle. You probably have debris in the seat area which causes faulty float action. Turn on the fuel tap again and catch the discharge in a clean small jar. Look for rust or other particles in the fuel. If all carburetors are affected, look at the fuel strainer screen just above the fuel tap bowl--no holes and seated properly. You may need to flush the tank if the interior is rusted or full of dirty fuel.