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Acura TL 2004-2008: Performance Diagnostic Guide

A change in performance is easily recognizable in the Acura TL. If you feel your car isn't performing like it once was, then read on to learn how to diagnose it.

By Bassem Girgis - May 12, 2016

This article applies to the Acura TL (2004-2008).

There are various components in the Acura TL that could directly affect its performance. Performance issues could be anything from weak acceleration to sluggish throttle response, and everything in between. The dealership charges a lot of money just for inspection, and once you realize how simple it is to check the obvious parts, you won't want to spend that kind of money for them to look at your car anymore. If you feel your Acura TL is driving differently, if you feel restriction in acceleration or rough idle, then read on to learn how to diagnose performance issue by yourself.

Acura TL 2004-2008: Performance Diagnostic Guide

Materials Needed

  • Socket
  • Long screwdriver

Step 1 – Check engine oil

It could be old or low.

Whenever you have engine problems, the first thing you should always do is check the oil. The engine oil works as a lubricant for the internal engine components. Over time, it starts losing its additives, which reduces its efficacy. Old engine oil or low engine oil could cause your car to run sluggish, this is doubly so if you're driving the car hard. The VTEC solenoid, which controls the engagement of VTEC, is oil-dependent, so if your oil level is low, the car will not engage VTEC and acceleration will feel weak. Engine oil should be changed approximately every 5,000 miles.

acura tl tsx tlx v6 J32 J35 J37 engine oil filter change burn
Figure 1. Check engine oil.

If the engine oil is at proper level and color, proceed to Step 2.

(Related Article: How to Change Oil - AcuraZine.com)

Step 2 – Check air filter

It could be dirty and clogged.

The engine's air filter works to filter all the air going into the engine. Ideally, the engine air filter should be changed annually. The dirtier the engine air filter gets, the more clogged it becomes, which restricts the air going into the engine, thus disturbing the combustion process. Use a socket to remove the four bolts around the air box, then check the condition of the air filter from the bottom. If it's too dirty, replace it to free up any restrictions. Inspecting the filter is easy, and replacements are inexpensive, so if your filter is trashed, consider inspecting it more regularly to keep your engine happy.

acura tl tsx tlx v6 J32 J35 J37 engine air filter clogged dirty
Figure 2. Check engine air filter.

If the engine air filter is in a good condition, proceed to Step 3.

(Related Article: How to Replace Air Filter - AcuraZine.com)

Step 3 – Check spark plugs

They could be burnt.

Spark plugs are a commonly ignored maintenance item. As they age, their ability to create spark lessens, and if left alone for too long, can result in an engine misfire; plus, a flashing check engine light is upset at you for neglecting your engine. Acura recommends replacing the plugs at 105,000 miles along with a bunch of other maintenance items; however, if your car is driven hard, consider shortening that interval. Spark plugs are cheap (~$3 each) and easily serviced, so don't feel the need to neglect them.

acura tl tsx tlx v6 J32 J35 J37 spark plug ignition coil misfire
Figure 3. Bad versus good spark plugs.

If the spark plugs appear fine, proceed to Step 4.

(Related Article: How to Replace Ignition Coils and Spark Plugs - AcuraZine.com)

Step 4 – Check fuel injectors

They could be clogged or faulty.

The fuel injectors are designed to squirt fuel into the engine, so when they get clogged, they don't spray the proper amount, thus disturbing the combustion process. You don't have to replace the fuel injectors when they are dirty, you can just remove them and clean them. However, if they are indeed dirty, then a replacement is a must to get your performance back. The fuel injectors are located under your fuel rails, so you will need to remove the fuel rails and find the injectors attached to them. To check their operation, with the engine on, hold a long screwdriver and let the top touch the injector. Then put your ear on the other end of the screwdriver to listen. If you hear a buzzing sound, the injector is working properly, but if you don't hear anything at all, then you're due for new injectors.

acura tl tsx tlx v6 J32 J35 J37 fuel injector
Figure 4. Check fuel injectors.

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