senor honda

This is something I wrote a while back. Deposits also play a significant role. You can change spark plugs till the cows come home and not attack the internal carbon:

I have had a lot of people recently ask me about fuel injectors and some of the symptoms that there are fuel injector problems. They have been asking me because they have tried the other fuel additives in their fuel and they haven't resolved anything.

I thought that it might be important to discuss some of the signs or symptoms of fuel injector problems.

1) Restrictions - Fuel injectors have really small orifices and it doesn't take very much of a restriction on an injector to lean out the fuel mixture. If you have a 6 to 12% on one injector it is enough to produce a misfire. I have seen people here posting about misfire codes on their cars.

When this happens, the unburned oxygen goes to the exhaust system and is picked up by the 02 sensor as being lean. What then occurs is the computer compensating by making the pulse width (time the injector is open) open longer. Because we have a speed density system, it will adjust the tables to be overly rich on the other cylinders as well. People then will experience their gasoline mileage going down yet the car seems to run fine.

We have talked about direct injection here before. While none of our cars has it, this type of system is even more sensitive to restrictions due to the need for exact fuel in the cylinders.

2) Engine Off Heat soak- When you turn off your engine, the injectors normally go through heat soaking. The fuel residues in the cylinders evaporates in the injector tips leaving a waxy compound behind. Since the engine is not running, there is no airflow going through the intake ports and obviously no fuel flowing through the injectors to solve it off the tips.

What happens is the heat bakes the waxy compounds into varnish deposits on the tips which will restrict proper spray patterns. Over time, this continual process partially or completely clogs the nozzle. Your engine doesn't have to have very much mileage for this to occur! Remember that short trips and increased amount of heat soak will cause this process to accelerate faster.

We talk about top tier gasolines as they are supposed to have detergent additives in them to keep clean the injectors, but when the varnish starts in the tips, the detergents are not aggressive enough to clear them off. Remember that these detergents are at a cost of 1/4 to 1/2 of 1 cent per gallon treated.

We petitioned the EPA to require gasoline companies to produce enough detergents to get clean and then keep clean all fuel injectors, but the EPA bought into the belief that if a car is clean and there is "enough" detergent to keep it clean, that is sufficient. Well continual heat soak and short trips do not accomplish this task and soon you are experiencing reduced fuel economy and performance.

3) Fuel Trim Issues- When the PCM is programmed from the factory, they are based on dyno testing from Mopar using a new engine on a stand. Fuel pressure is within the normal range for that engine and all the injectors are vaporizing the fuel effectively.

The PCM with it's adaptive strategy and speed density tables assist in adjusting the short term and long term adaptives to compensate for differences in fuel pressures and fuel delivery to maintain the right A/F (Air/Fuel) ratios. However, it is limited to how much it can adjust one way or another:

-Where we run into problems with our type of system is that it is unable to increase the injector pulse width enough to offset the differences in a compromised fuel injector.

-Also if it becomes clogged or greatly restricted with varnish deposits it will fail to deliver the normal dose of fuel when the coil is energized

- Fuel pressure will suffer and go below specs from a weak pump or a partly plugged fuel filter

These can produce an A/F mixture that is too lean and cause misfires.

4) Resistance is not correct- The solenoids on our injectors produce a magnetic field that slides the injector pintle (fuel needle) backwards opening the orifice when it is energized. It must be strong enough to overcome the spring pressure that wants to keep it closed. If it is weak, it may not open all the way. Typically shorts, opens, and high resistance in the injector solenoid can cause injectors to fail and also clog faster.

5) Injector Leaks - A fuel injector that is leaking....could be due to carbon build up or a partly sticky pintle will cause longer crank over times. This condition will cause the fuel rail to lose pressure while the car is sitting. This is why you will see increased cranking because the pump has to "fill up" the rails on one or both sides of the engine.

6) Misfire Codes - As I said before, we have seen a lot of misfire codes recently. My experience tells me that it is most likely a lean misfire that will trigger the codes. P0300 random misfire or different codes for individual cylinders. This too is dependent on the condition of the fuel injectors to deliver proper vaporized fuel. This also causes deposits in the cylinders that act like other spark plugs contributing to this issue! It will continue due to the fact that you can't clean these deposits out without a serious cleaner using ACES IV-FIC!

7) Contaminated Fuels and fuel tanks - The symptoms that this creates are cranking and no start, hard starting, stalling, loss of fuel economy and loss of power. The symptoms are more pronounced after you refuel the car as you are mixing things up in the tank. Phase separation is a real issue with ethyl alcohol fuels as they use atmospheric moisture to drop out of the gasoline into the water in the bottom of the tank. Your 93 or 91 octane fuel turns into 83 or 81 fuel real quick. Also formic acid is created due to the conversion. Alcohol fuels are hygroscopic....means they absorb moisture.....and cause drivability issues.


More reactive oils- Using an engine oil that has a lot of reactive compounds that vapor or outgas into the PCV system.... even when having a catch can......will also cause fuel injector problems. The oil blowby and residues go right back into the intake and end up mixing with the port injected fuel and air mixture. The octane value of these compounds from the reactive oils are very low and really hamper performance and mileage. Also these oils....once separated......then leave heavier less reactive compounds in the crank case and turn them into a sooty heavy oil viscosity. More wear, and lower mileage is the result.


Most of these issues that we have discussed are addressed by using ACES IV FIC...the fuel injector cleaner to really aggressively get things clean and then are prevented by using ACES IV in every tank of fuel. This is why people that use ACES IV and then go on to use QuantumBlue Lubricants DON"T have fuel deposit or oil deposit issues. Their cars run like new mile after mile and the condition of these engines are backed up by the oil analysis performed by third party companies like ALS and Blackstone.

I thought it was time to address these as I have been seeing this a lot recently.