Fuel Sensor Installation & Calibration (Tel Napai): Complete Guide
On this page
- 1–3: Preparing the tank
- 4–6: Fitting the sensor
- 7–13: Cleaning and sealing
- 14–17: Securing and calibration
- FAQ
Fuel sensor installation and calibration — known locally as Tel Napai — is the most technical part of setting up fuel monitoring, and getting each step right directly determines how accurate your theft and refill data will be afterward. This guide walks through the complete fuel sensor installation and calibration process, step by step, with a clip for every stage.
Preparing the tank
1Measure sensor height first
Before drilling anything, measure the correct sensor height against your specific tank.
Sensor Height Measurement
2Drill using a 32mm bit
A 32mm drill bit is the standard size for most tank types when fitting a dedicated fuel sensor.
32mm Drill Bit
3Use a self-drilling bit on thick tanks
Thicker tank walls need a self-drilling bit rather than a standard one to get a clean, correctly sized hole.
Self-Drilling Bit in Thick Tank
Fitting the sensor
4Cut and install the sensor
With the hole prepared, the sensor itself is cut to fit and installed into position.
Cut & Install Fuel Sensor
5Fit the sensor washer
The washer creates a secure, leak-resistant seal around the sensor body.
Sensor Washer Fitting
6Install the pungli pipe separator
The pipe separator keeps the sensor reading correctly by managing fuel flow around it inside the tank.
Pungli Pipe Separator
Cleaning and sealing
7Clean the sensor pipe using petrol
A petrol wipe-down removes residue from the pipe before sealing, helping the seal actually hold.
Sensor Pipe Cleaning Using Petrol
8Clean and seal the sensor body
The sensor body itself is cleaned and sealed before final fitting.
Cleaning & Sealing a Sensor
9Seal the drain hole
The drain hole needs its own seal, shown here in two slightly different tank configurations.
Seal Drain Hole — Example 1
Seal Drain Hole — Example 2
10Remove old black tape from the drain hole
Any old tape or residue should be fully removed before applying a fresh seal.
Remove Black Tape From Drain Hole
11Seal the fuel level sensor
The main fuel level sensor gets its own dedicated seal to prevent any leakage around the fitting.
Seal Fuel Level Diesel Sensor
12General sensor sealing method
A general demonstration of the sealing method that applies across most standard sensor types.
How to Seal Fuel Sensor
13Seal the Escort TD BLE sensor variant
The Escort TD BLE sensor variant has its own specific sealing approach, shown here.
Seal Escort TD BLE Sensor
Securing and calibration
14Fit the cable seal and protective cap
A protective cap and cable seal guard the connection point against dust, moisture, and vibration damage over time.
Cable Seal & Protective Cap
15Apply the final pull-tight seals
Two pull-tight seals secure everything in its final position before the tank is closed up.
2 Pull-Tight Seals
16Run first-time setup and calibration
With the physical installation complete, first-time setup in the app calibrates the sensor against the actual tank, so readings reflect real fuel levels from day one.
First-Time Setup & Calibration
Skipping or rushing calibration is the single most common reason a correctly installed fuel sensor still produces inaccurate data afterward — the physical fitting and the calibration step are equally important parts of fuel sensor installation and calibration, not one followed by an optional extra. For general vehicle modification and electronics fitting safety practices, see guidance from the Ministry of Road Transport and Highways.
FAQ
What does “Tel Napai” mean in fuel sensor installation?
Tel Napai refers to the fuel sensor calibration process — matching the sensor’s readings to the actual physical fuel levels in a specific tank. Can I install a fuel sensor myself, or do I need a technician?
Given the drilling, sealing, and calibration steps involved, fuel sensor installation and calibration is generally best handled by a trained technician to ensure accuracy and a proper seal. What happens if calibration is skipped?
Without calibration, the sensor may report technically functioning but inaccurate fuel levels, undermining the accuracy of theft and refill detection even though the hardware itself is correctly installed.
See the full guide: GPS Tracker Installation Process — Complete Guide