Fix for that bad MPG and rough stutter at 1800 rpm.

[dcmfx]

I have been having decreasing mpg over the past year or more. My MPG used to be 58-60 range. It went down to 51-52 range with a dull driving car. I also had significant stuttering at about 1800rpm in a high gear just driving along at about 40mph. I had tested my EGR system, and checked the ports into the intake manifold and they were all clear. I replaced my O2 sensors and that perked it up just a bit, but it still continued to decline. I did the plugs and air filter to no avail.

I just cleaned my fuel injectors, and that was the problem! None were terribly bad, but all were dirty, and they were unbalanced with one being OK and 2 being less than satisfactory. I pulled them out and sent them out for cleaning. The removal and replacement was very easy, with just changing out the rubber isolators and o-rings. My mileage got better every day for the week after. I assumed then that the ECU was a learning type and slowly re-learning the good injectors, so I pulled the battery wire for a few minutes and resetting the MPH gauge, it was 59 today and ran so much better!

Seems with few cylinders and very tight emissions tolerances, just a little dirt and clogging will throw it all out. I would bet the lack of balance does even more trouble. If all 3 are evenly dirty, the ECU should just adjusts itself to them. But if they are unbalanced, the ECU only reads Oxygen, and will adjust itself to the leanest injector, being the one that allows Oxygen through while the other 2 get more fuel and burn all Oxygen and run rich. If they had O2 sensors per cylinder and adjust ratio per cylinder, that would not happen, but these cars don't. So clean your injectors if you are getting that low MPG feeling... And pull the battery to reset the Air/Fuel ratio map when you do it!

[Willie Williford]

Did they flow test them with a "pattern graph". If so, what was the flow rate?
HTK
Willie

[dcmfx]

cc/min pattern

Before cleaning:
1 141 good
2 135 fair
3 128 fair

After cleaning:
1 146 excellent
2 145 excellent
3 145 excellent

$80 for cleaning & shipping back

I have had a V8 run better with one injector at 0 cc/min fully clogged than this 3cyl with slightly dirty injectors...

I had the lingering CheckEngine light appear last December. Honda replaced the engine ECU and it did not come back. I also had the IMA light last December and they changed the battery with Honda "re-manufactured" battery and said they were not supposed to replace the MCM and BCM modules even though it was a 2001. I even called up Honda of America and was told there was no repair orders saying they should be replaced with the battery. Otherwise, 110,000 miles, normal maintenance, freeway commuter car. Bought at 55,000 miles used about 3 1/2 years ago.

[gjenn12]

Where did you send them for 80.00 I cannot seem tofind any body over 125.00 thanks

[dcmfx]

RC Engineering in Los Angeles. They have a web site you can order, then send yours in. I have used them twice now per previous web recommendations. I am happy with them.

no financial interest
dan

[crxgator]

awesome, i wonder if this is one of the problems im having, because i can never get over 55 mpg, even with my stock rims/tires.

[Artric]

Nice. Anything I can do to get a decent cleaning without putting the car down? Also, how long did it take?

[RobertSmalls]

The fact that they flow test them is encouraging. I wonder what kind of service you get when you pay the quick lube place $80 to clean the fuel injectors.

I'd also like to see before and after flow testing on a $3 bottle of fuel injector cleaner.

Edit: it looks like lots of speed shops do fuel injector cleaning and testing. I found one local to me. If only I had dirty injectors that wouldn't respond to the $3 option.

[02insight]

Originally Posted by RobertSmalls

I wonder what kind of service you get when you pay the quick lube place $80 to clean the fuel injectors.

I asked a local lube place, and they dont even take them out of the car, They just run some solution through the fuel system and thats it. I know a local place that would do the cleaning/flow test etc. for $20/injector. With us having only 3 of them, that's just $60. Not a bad investment for possibly making the injectors like new again, compared to more than $100 each for new injectors

[MN Driver]

FWIW, I used a bottle of Chevron Techron fuel system cleaner for one gas tank full and my car doesn't have the 'herky jerky' feeling anymore. It felt exactly like every misfire I've ever had before but I've read everything about the EGR here and figured I'd have to take all that apart to fix it but a tank after that stuff and I haven't had it anymore. I still seem to have some issues with trying to enter lean burn sometimes when I'm holding the MPG gauge at 100, it will shoot to 80 and not engage the first few times during a trip because of the spike, but then again for all I know it's probably normal.

The bottle is worth a shot but if the injectors are really bad, they are probably way beyond the help of something from a bottle. In my own experience, I've used it as preventative maintenance every 10k miles or so.