At M & R Automotive, we’ve seen our fair share of Lexus ES 350s with recurring hot-start problems needing our specialist level of diagnosis and repair. In many of these cases the starting problem is traced back to faulty fuel injectors, fuel pressure problems, ignition component issues or a bad engine sensor.
In many of these cases the Lexus ES 350 will still start reliably when the engine is cold, yet cranks for an overly long time once it’s fully warmed up. A problem like this can have multiple causes, each of which needs professional diagnosis before it leads to more expensive repairs.
Fuel injector problems are one of the most common causes of hot start issues with a Lexus ES 350. If just one fuel injector leaks after the engine is turned off, residual fuel might gradually start to enter the intake or combustion chamber of the cylinder. This can create an overly rich mixture, which essentially floods the cylinder making it hard to restart while the engine is warm.
At the same time, a leaking fuel injector could also lead to a loss of fuel pressure. Instead of maintaining pressure within the fuel system, the pressure within the fuel line drops while the Lexus sits. When you start it, the system might need to crank for longer until it reaches the necessary pressure level.
A failing fuel pump or check valve is another possible cause for hot starting problems in a Lexus ES 350. In a case like this, you’ll get the same symptoms as a leaking fuel injector, with the fuel pressure bleeding down after the engine shuts off. So, it’s not enough to simply assume the hot start problem is caused by a bad fuel injector.
Our diagnostic process starts by looking for patterns in the starting problem to help narrow the possibilities. Then we compare this with the technical information our equipment gives us.
The engine in a Lexus ES 350 needs a properly timed spark to properly ignite the air-fuel mixture. Something as simple as worn spark plugs or faulty ignition coils could produce a weak or inconsistent spark, which would make a warm engine harder to start.
At the same time, a Lexus ES 350's computer relies on information from several sensors to determine how the engine should operate. A problem with the coolant temperature sensor, crankshaft position sensor or camshaft position sensor may provide incorrect information during startup.
Sensor problems may produce additional symptoms such as the engine running rough, a hard idle, intermittent starting problems or a check engine light. In many of these cases the car’s computer stores a diagnostic code to help determine the underlying cause.
If your Lexus ES 350 has been experiencing hot start problems, you need to call M & R Automotive to schedule an appointment. We’ll inspect the system to determine if it is a fuel injector problem and recommend the best repair options based on what we find.
