Isn't it possible that this is just the "lean burn" kicking in?
I wondered that too. I remember Dan (krousdb) describing it kicking in, and if I'm not mistaken, he described it as a noticable loss of power, and that he had to respond by pushing the accelerator more to maintain speed.
If you push too much, maybe it kicks back out of lean burn. (But what do I know about lean burn - I drive a gas guzzling Firefly with the antiquated technology of a farm implement .)
thanks for that, pretty informative. i was going through the stacks of paperwork that came with the car, and last tuneup was done 2 years ago, but they didnt use the ZFR4F-11 plug, they used ZFR5F-11, is that a big deal? im going to try and find a set of the right plugs today, and while im at it do a nice big tuneup
I had the same problem in my VX when I bought it, but the mileage was way worse. the car did have nearly 290K miles on it though.
The spark plugs that were in there were the ZFR5F as well, they don't like Lean Burn, get the right ones in right away! Get the motor de-carbonized by going to Honda dealer or a Chevrolet dealer and getting the top engine cleaner and following this procedure: The easiest way: go to a Fleet Farm or Lowes or any home and garden store and get a small (handheld, about one liter) pumping container (commonly used for spreading insecticides or liquid fertilizer). take the intake hose off of the car at the throttle body. Idle the motor and spray the liquid into the motor until the entire can is gone. Make sure not to kill the motor yet. Once the fluid is gone, let the motor die, or kill it yourself. Wait 15 minutes. Then start the car and drive it somewhat hard until all the smoke stops coming out of the exhaust. It stops smoking faster the harder you drive it.
The harder way: Disconnect the Brake Booster vacuum hose while the car is running and let it "sip" the fluid out of the bottle slowly until gone. Then wait 15 minutes then drive the car to get teh smoke (carbon) out.
After all that is said and done. Get a new O2 sensor from Ebay, get the right plugs in, and you should be set.
At least that is what I did to mine. All that made it go from <250 miles per tank (the previous owners claim) to ~475 miles per tank. That was all before I actually started to drive for FE with it as well.
at least around here if you ask the auto parts store for spark plugs for the vx, their computer tells them to sell you the ZFR5F-11 plugs, I'm not sure why, but that is what they are told is the current correct part.
what the dealer told me was causing my loss of power at crusing speed was the weak signal from he o2 sensor was sending the computer in to it's programed loop, I'm not sure if it's the temp sensor in the o2 sensor maybe not telling the computer that it's warmed up enough to be acurite, or what it might be, but in that programed loop it's giving you an air fuil mix based off throttle possition, and that is crude enough that you have to move the throttle quite a bit for the computer to catch on, thus the loss of power, if you can get the o2 sensor out (with only 92,000 miles it might come out) take a look at it, it should be a grey color, if it's dead, then like I said it will be black and sooty
so today i picked up a DVM to check the o2 sensor, and about 180$ worth of tuneup stuff, the usual plugs, wires, dist cap, rotor, air filt, fuel filt, switching to synt. oil(5-30), pcv valve, 2 cans of sea foam (i hear GREAT stuff about it, no idea how to use it however)
anybody care to help me test my o2 sensor by telling me how to check it?
NickF829: Let me know if the OEM PCV valve is still in the engine. Apparently the factory PCV is open all the time keeping the crankcase under constant vacuum (to help with FE). I stupidly replaced mine with an aftermarket one that had the innards in it and had to use my OEM one on my wifes car for a quick repair.
To use the sea foam, just follow my instructions in my above post.
Ryland: Many car parts stores have the wrong info for the D15Z1 motor. I've found that Checker/Kragen has the wrong spark plug wires, spark plugs, and timing belt in their computer. And if Nick posts back about the OEM PCV valve (all black and no innards) then they also have the wrong PCV valve.
as far as checking the O2 for proper signal...I've seen people use a butane torch to heat the tip and then remove it alternating doing so while the positive lead is connected to the signal wire and the ground is attached to the metal body of the O2. Not sure how if this is good for the O2 but the people that use them on the single wire O2s are only out $20 if they fry it.
Best way to test the O2 is by looking at the signal it sends to the ECU through data logging.
where do i hook the dvm to though while driving? the o2 sensor has 5 wires coming off it at the exhaust manifold, where does that wire run to the pcu and is the pcu in the passenger floorboard, if so which wire do i hook the DVM to
the PCV i pulled out was blue and looked to be replaced somewhat recently. should i goto honda and get a different one?