Has anyone used any of these products? If so which ones and did you like them....I've used that STP fuel inj. cleaner and I couldn't tell no difference...I tried that Vavoline brand from wal-mart and I could really tell a change...Has any of you all had the same or close to the same....

 

It's hard to tell any difference from one or two treatments but I've heard pretty good things about Redline products and even Techron. I've never tried Redline products but I used Techron in my 90 pathfinder every other oil change and it held up to 150,000 miles without a single problem. I just made sure to get the routine maintenance done when needed. Not to fully attribute my luckiness to the Techron but it sure didn't hurt in my case.

 

You tried STP and couldn't discern any difference? That means your injectors weren't sticking. You spent your money on a cure for a disease you didn't have.

I've had good results with fuel injector cleaners, the kind you put in the gas tank. I recommend it where there is a clear indication of an injector problem. I don't recommend it for use as a preventive measure.

IMHO all name-brand fuel injector cleaners are equally good at cleaning injectors. Techron claims to also clean carbon deposits from the stems of intake valves. Certain engines -- older four cylinder Toyotas in particular -- have this problem. I've never heard of it in the VQ30DE engine used in our 4Gen Maximas. For this reason I would not pay the higher cost for Techron.

 

This is where Daniel and I disagree. This is why:

Infiniti TSB

Engine Cranks, But Will Not Start/Hard To Start
Classification:
EC97-020a

Reference:
1TB97-041a

Date:
March 18,1998

Title:
ENGINE CRANKS, BUT WILL NOT START OR IS HARD TO START

APPLIED VEHICLES:
All models 1990-97

SERVICE INFORMATION
Use this bulletin if the engine cranks over normally, but is difficult to start or will not start at all.

This situation may be caused by small carbon deposits falling onto the intake and exhaust valve sealing surfaces which results in loss of compression.

Short Driving Cycles - Q45. J30, I30 and G20

Modern multi-valve engines designed for efficient low-friction operation may sometimes experience carbon build-up on the valves after driving a very short duration (less than 1 minute). A hard start or no start incident may occur on the next starting attempt. If this pattern is observed, the vehicle can be started by following the cold weather starting procedure below.

Cold Weather Starting - All Models

During cold whether, Nissan suggests the following procedure to make starting the vehicle easier when this incident occurs. This procedure is a continuation of the procedure outlined in the owners manual and should be used to remedy a "No Start" condition when the ambient temperature is low.

1. Depress the accelerator pedal approximately 1/3 of the way to the floor.

2. Hold the accelerator pedal in this position and crank the engine.

3. Once the engine has started, release the accelerator pedal. (Do not race the engine while warming it up.)

4. If the engine does not start within 10 seconds, wait at least 10 seconds and repeat steps 1 through 3.


Once the engine is started in cold weather conditions, run the engine for a minimum of 2 to 3 minutes before shutting it off. Starting and stopping the engine over a short period of time may make the vehicle more difficult to re-start. This type of usage may also adversely affect a vehicle's fuel economy.

Another factor that may affect a vehicle's starting performance in cold whether conditions is the viscosity or thickness of the engine oil that is used. An API SG or SH quality 5W-30 is the preferred engine oil to be used year-round for most models. In colder weather, oil that is rated 5W-30 will not thicken as much as a 10W-30 rated oil; this makes it easier to start the engine and maintain a stable idle during warm up.

 

Redline makes a good product,but as stated, you probably didnt need it. Save your money

 

I'm not experienced enough to know those clear indications. What symptoms will a car with an injector problem exhibit?

 

Sticking fuel injectors may give rise to a variety of symptoms, depending on whether the sticking is occasional or constant, depending on whether one injector is sticking or several.
- Hard starting with warm engine.
- Black smoke at the tailpipe.
- Premature failure of Oxygen Sensors.
- Stumble and surging rather than smooth acceleration.
- Failing (or just barely passing) the smog test.

 

I don't know that I've ever had an Oxygen Sensor fail. How do I know that it's happened?

Thank you, by the way, for your help, Daniel.

 

There are two degrees of failure.

1) The Oxygen Sensor is "dead".
The signal from the Oxygen Sensor is outside the normal range, or completely absent. The Engine Control Module (the computer) turns on the Malfunction Indicator Light and stores one or more Diagnostic Trouble Codes. This failure mode is obvious because of the dashboard warning light.

A dead Oxygen Sensor is a severe failure and should be repaired promptly.

2) The Oxygen Sensor is "tired".
The Oxygen Sensor still works but it responds slowly to changes in the oxygen concentration in the exhaust stream. There is no MIL or DTC. This failure mode is less obvious. The symptoms are increased fuel consumption, decreased engine power, and a feeling of sluggishness. The throttle response is not crisp, like it was when the car was new. An Oxygen Sensor may become tired due to high mileage or being "poisoned" by exposure to various substances including leaded fuels, anti-freeze, anti-seize, RTV sealants, and the residue of burned engine oil. A "tired" Oxygen Sensor is still doing its job, but not performing well.

A tired Oxygen Sensor is not a severe failure and the car may be operated safely.


You may have your Oxygen Sensor(s) tested. There are electronic testers made for this specific purpose. In addition, a technician with an automotive oscilloscope can test Oxygen Sensors. The signal from a healthy sensor varies from a low threshold (around 0.2 volts) to a high threshold (around 0.8 volts), and it sweeps back and forth between those extremes about 10 times per second. If the scope trace shows the Oxygen Sensor signal failing to reach either extreme, or oscillating between them at a frequency slower than 10 cycles per second, that is evidence of a "tired" sensor.

I've read that a bad Oxygen Sensor can sometimes be rejuvenated by removing it, clamping it in a vise, and heating the sensing tip red hot with a propane torch. This is said to burn off a crust of deposits which interfere with its operation. I've never tried this torch trick myself, so cannot vouch for it's effectiveness. If you have a sensor which is already dead, you have little to lose.

For more information about Oxygen Sensors see:
http://www.volksparts.com/o2sensors.htm
http://members.aol.com/carleyware/library/o2sensor.htm