Fitech Handheld Controller: Checking Fuel Pressure

The Fitech handheld controller is a feature of the Fitech Fuel Injection system. It is used to adjust the ignition control system and does not need to be kept connected at all times for the system to function. The controller can be used to check the fuel pressure, which is regulated at around 55-58 psi. However, some users have reported issues with fuel pressure dropping when the engine is hot, which can cause the engine to stall.

Fuel pressure regulator issues

Fuel pressure is an important aspect of a vehicle's performance, and issues with the fuel pressure regulator can cause significant problems. The regulator ensures the correct fuel pressure is maintained, allowing the optimal amount of fuel to enter the combustion chamber for ignition.

Engine Performance Problems

A faulty fuel pressure regulator can cause a loss of fuel pressure, leading to hard-starting, rough idling, stalling, and a lack of power. The engine may struggle to crank due to insufficient fuel, or it could flood the combustion chamber with excess fuel. This can result in the engine not starting at all.

Check Engine Light

The check engine light can be triggered by various issues, including engine performance problems caused by a faulty regulator. A mechanic can check the diagnostic code to determine if the regulator has triggered the light.

Black Smoke from the Exhaust

A bad regulator can cause the engine to run rich, resulting in incomplete combustion and black smoke from the tailpipe. This is often accompanied by a strong fuel smell.

Fuel in the Regulator's Vacuum Line

A ruptured diaphragm inside the regulator can allow fuel to be drawn into the vacuum line and the engine's intake manifold. This can lead to performance issues and an engine that runs rich.

Vehicle Cranks But Doesn't Start

A faulty regulator can prevent the engine from receiving the proper fuel pressure, resulting in a vehicle that cranks but refuses to start.

Fuel Leaking from the Tailpipe

A faulty regulator can cause the fuel injector to pump excess fuel into the combustion chamber. This extra fuel may not burn and can leak out of the exhaust pipe.

Engine Backfires

When a bad regulator allows extra fuel into the engine, it may not all burn before the exhaust valves open. This creates a fuel leakage into the exhaust headers, where it combusts, resulting in engine backfires.

Fuel Leakage

A broken diaphragm or seals in the regulator can cause fuel to leak, often accompanied by a strong fuel smell.

Reduced Fuel Efficiency

Improper fuel pressure can cause an unbalanced air-fuel ratio, leading to reduced fuel efficiency as the engine has to work harder.

Noisy Fuel Pump

Low fuel pressure can cause the fuel pump to strain when drawing fuel, resulting in a loud whining sound.

Fuel pump problems

• Loud whining noise from the fuel tank: A damaged fuel pump may make a loud, whining sound, indicating a problem. The normal noise your pump makes is a low hum. This noise may also occur if you are low on fuel or if the fuel in your tank is contaminated.
• Trouble starting the car: If your vehicle's fuel pump is unable to deliver fuel to the engine, the car will struggle to start and run. A worn pump loses pressure, causing the engine to be starved of gasoline.
• Engine sputtering or stalling: If your engine sputters, stalls, or dies while driving, especially during acceleration or when under stress (e.g., towing a heavy load or driving uphill), it could be due to low pressure caused by a faulty fuel pump. The engine isn't getting the required fuel and air mixture to initiate combustion and power the car.
• Engine surging: A surging engine, where the vehicle repeatedly picks up and drops speed without any input from the driver, can be caused by a bad fuel pump sending too much fuel to the engine.
• Lower fuel efficiency: If your vehicle is consuming more fuel than usual, it could be due to a faulty fuel pump letting excess fuel into the engine.
• Power loss: A failing fuel pump may cause your vehicle to lose power while accelerating, as it can't keep up with the engine's demands at higher speeds.
• Engine overheating: If the fuel pump causes your engine to overheat, it will stall. An old and worn pump motor can get too hot, causing the entire engine to overheat.
• Poor performance on steep inclines or with heavy cargo: If your vehicle loses power when driving up steep hills or when loaded with cargo, it could be due to the engine not getting enough fuel under stress.
• Vehicle not starting: While there are many reasons why a car won't start, a faulty fuel pump could be one of them. If the pump is dead, it won't be able to deliver fuel to the combustion chamber.

Faulty wiring

Communication Problems:

One of the most common issues with the Fitech handheld controller is the inability to connect to the ECU, resulting in a "No Response" message. This problem often arises from a faulty cable connecting the controller and the ECU. The cables provided with Fitech units are sometimes fragile and prone to breakage if mishandled, leading to signal loss. To resolve this, users should inspect the communication cable for any signs of wear and tear and replace it with a shielded cable if necessary. It is important to ensure that the cable is handled with care to avoid bending or pinching, which could cause internal damage.

Unstable Power Supply:

An unstable power supply to the ECU can also disrupt communication with the handheld controller. The ECU requires a consistent 12-volt power source and a good ground connection. Faulty wiring, a weak battery, or poor grounding can cause voltage fluctuations, preventing the controller from functioning properly. To address this, users should check the power connections and ensure they are clean, secure, and provide a steady voltage. This may involve upgrading the alternator, replacing the battery, or improving wiring connections to maintain voltage stability.

Power Loss in Handheld Controller:

In some cases, faulty wiring can lead to power loss specifically in the handheld controller. This could be due to a bent or damaged pin in the connection, preventing the controller from receiving power. Users experiencing this issue should carefully inspect the power connection for any signs of damage or misalignment. It is also recommended to contact Fitech support, as they may provide guidance or suggest changes to the connector design to prevent similar issues in the future.

Electrical Interference:

While not directly caused by faulty wiring, electrical interference, or electromagnetic interference (EMI), can be exacerbated by poor wiring practices. Running EFI wiring alongside ignition wires or insufficient shielding on signal wires can increase the risk of interference. This, in turn, can lead to erratic sensor readings, ECU resets, engine misfires, and fluctuating data on the handheld controller. To mitigate electrical interference, it is crucial to separate EFI wiring from ignition components and high-voltage wires. Using twisted pairs for signal wires and grounding all EFI components at a single point can also help reduce EMI.

Vacuum Leaks:

While not strictly a wiring issue, vacuum leaks caused by poorly sealed intake manifolds, cracked hoses, or leaks around the throttle body gasket can lead to idle control problems. These leaks introduce unmetered air, disrupting the air-fuel mixture and making it challenging for the ECU to maintain a stable idle. To address this, users should inspect and seal any vacuum leaks, calibrate the IAC according to Fitech guidelines, and ensure all throttle body components are in good condition.

Vacuum line issues

Firstly, it's important to understand the role of the vacuum line. The vacuum line is connected to the Fitech Power-ader 400 and supplies vacuum pressure for the brake booster. A properly functioning vacuum line ensures that your brakes work effectively. However, issues with the vacuum line can lead to fuel pressure problems.

One common issue is the presence of fuel in the vacuum line. This can be identified by disconnecting the vacuum hose from the Fitech Power-ader 400 and checking for fuel or a strong fuel smell. If fuel is present in the vacuum line, it could be due to a faulty check valve or other issues with the fuel delivery system. It is recommended to replace the check valve and ensure that all fuel lines and connections are secure and intact.

Another potential issue is a lack of vacuum pressure, which can affect the performance of the engine. To diagnose this, you can use a vacuum gauge to measure the vacuum pressure in the line. If the pressure is low, there may be a leak in the vacuum line or an issue with the brake booster itself. Inspect the vacuum line for any cracks, loose connections, or damage that could be causing a loss of vacuum pressure.

In some cases, the vacuum line may not be connected to the Fitech unit. It is recommended to consult a professional mechanic or a Fitech specialist to determine if your specific setup requires the vacuum line to be connected. They can also advise on the correct routing and installation of the vacuum line to ensure optimal performance.

Additionally, issues with the fuel pressure regulator, which is built into the Fitech unit, can impact fuel pressure. To troubleshoot this, ensure that the regulator is receiving full vacuum pressure (>58 psi) from the pump. You can measure the pressure at idle before giving it gas to identify any potential issues with the regulator or the pump itself.

Remember to exercise caution when working on your vehicle's fuel and brake systems, as they are critical for safe operation. If you are unsure about any aspect of the diagnosis or repair process, it is always best to consult a qualified mechanic.

Fuel filter problems

Fuel filters are a common component in vehicles with internal combustion engines, and they play a crucial role in ensuring that dirt and impurities are removed from the fuel before it enters the engine. However, fuel filter problems can cause a range of issues with the vehicle's performance. Here are some common problems associated with fuel filters:

Hard to Start or No Start-up

A clogged fuel filter is often the culprit when a vehicle is hard to start. As the filter becomes dirty, it restricts the fuel flow, leading to inconsistent fuel supply, which makes it difficult for the engine to start. In some cases, if the filter is completely blocked, the vehicle may refuse to start at all since the engine requires fuel to ignite.

Engine Performance Issues

A dirty or clogged fuel filter can cause a range of engine performance issues. These include engine hesitation, especially when accelerating from a stop, and erratic low-speed performance. The engine may also stall, either while driving or shortly after starting the vehicle, due to inconsistent fuel flow through the clogged filter.

Engine Misfires

A clogged fuel filter can lead to engine misfires, where the engine randomly hesitates or misfires under heavier loads. This is because the clogged filter depletes the fuel supply to the engine, causing the amount of fuel to vary at different speeds, resulting in shaking or stuttering.

Decreased Power and Acceleration

A severely clogged fuel filter can restrict the fuel flow to the engine, leading to a decrease in overall engine power, especially noticeable during acceleration. The engine's computer may also restrict output to protect the engine from potentially damaging particles, causing the vehicle to feel sluggish or even go into limp mode.

Check Engine Light Comes On

Some vehicles have fuel pressure sensors that monitor the fuel system's pressure. If a clogged fuel filter causes low pressure, it will trigger the Check Engine Light to alert the driver. However, this light can also be due to various other issues, so scanning for trouble codes is recommended.

Damaged Fuel Pump

A clogged fuel filter can put excessive pressure on the fuel pump as it tries to push fuel through the restriction. This can lead to damage to the fuel pump and prevent the necessary amount of fuel from reaching the engine.

Frequently asked questions