Hi, well after many days of rough idle and stalling after the engine warmed up, I finally got an engine light to come on in my 96 DX. The message was that the fuel system was too lean. The fellow who worked on it said he called the Honda tech center and they recommended he clear the code. He drove the car around for about 1/2 hour after doing that and said it ran just fine the entire time. It seems to me that it would not make sense that merely clearing the code would actually fix anything so I believe this problem will come back. I know the engine runs off default factory settings while an engine light is on and the car ran fine during that time. If the situation comes back the mechanic thinks it is probably a fuel pressure regulator and he figures to change it then. How can I know this is the solution? I mean, what is the likely cause of the engine light? Last time the light came on it was due to exhaust catalyst efficiency too low so I changed out the catalytic converter a few months back but did not change the O2 sensors. Everything ran fine until this new issue. Could they be related? I had the rough running for a while before the light came on came on.

Any comments would be great.
KR

 

Maybe you injectors are clogged. To see if the fuel pressure regulator is bad, i think that you can install a fuel pressure tester and find the fuel pressure. I think hondas have a test fitting on the fuel rail. So check the fuel pressure.

 

Thanks for the tip. I will check that out. I think the injectors are ok becasue the car seems to run well most of the time. I have also run injector cleaner through the system a few times. I pulled the plugs and they look very clean, just a little dark, like they should be. I also have a new fuel filter. What is odd is that the car is just a little sluggish at first but usually that goes away after a few minutes then once it significantly warms up it will start to idle roughly and want to stall. If you bump the throttle quickly once the engine recovers from the fast speed to the slow speed very roughly, like it wants to stall but it seems to hold on and eventually settles down. It is tough to drive becasue it feels ready to stall every time you have to stop.

What about warming up makes this get worse? I would think that a fuel regulator or injectors would either work right or wrong all the time not intermittently. So I am wondering if an O2 sensor might be triggering something to adjust the vacume line that controlls the fuel pressure regulator. I wish I knew more about how these things work... The car has a new catalytic converter but still has the same O2 sensors.

 

I was gonna say cat, but you said it's new. I'd go for the O2 sensors.

 

What kind of injector cleaner did u use. The one that you pour down the gas tank is ok if u constantly are using it but if you haven't done it for a while, there is an injector cleaner that you pump through the fuel rail or the fitting where the filter goes. You might wanna try that if you haven't already.

 

Murphy's Law sucks man.

 

to check your pressure reg. try to rig up a in line fuel pressure gauge between the fuel filter & injector rail --with engine runnin pull off the vacuum line on regulator--if pressure goes up --its good

 

Thanks All,

I will look into the fuel pressure check. I have run the injector cleaners through the tank and since the motor runs fine at times I would think the injectors are ok, plus I would expect the plugs to look bad if the injectors are acting up. As a rudamentary check, I used a pipe to see if the injectors were clicking and each one sounded active. The car does not sound like it is missing, it just idles too slow like it is struggling for gas. I am also getting a bit of rough acceleration when it is cold. At low RPM it accelerates normally but slow gentle acceleration will get rough and hesitate around 3000-4000 until the car warms up a little. That and the rough idle began at the same time. After a brief warm up the acceleration is normal but the rough idle at a stop begins. This is frustrating. I thought O2 sensors because I had a similar thing happen on a Ford Taurus once it warmed up but I just want to be sure before I invest hundreds chasing guesses.

Odd as well I think I am sensing that it runs better with a full tank of gas and starts to act up when the tank is below half. I may be imagining that though.

Thanks All,

 

is it a stock cat, b/c in the experience i've had w/ working on honda's is that an aftermarket universal cat doesn't usually work very well. I know the stock cat's are very pricey, but you can find a good performance one on ebay that should do the trick.