Hi all,

I really need some expert advice with this car. My wife has a 2-door automatic 98 Accord with V6 engine and around 156,000 miles. We have an intermittent problem that has come and went for the past year and half or so. First I will run down the symptoms then explain what we have tried so far...

The car will usually run fine for the first 10 minutes or so of driving. Then, without warning, while cruising at any speed from around 35 to 60+ the rpms will drop down and the car will hesitate when given more throttle before it finally lurches forward. The process repeats itself for sometimes a few seconds, sometimes a few minutes, then drives normally again for a period of time. Sometimes it does this twice in a 20 minute drive, sometimes 10+ times, sometimes not at all. However, lately it has become an every day occurrence. My wife feels unsafe driving the car because, at times, she cannot hold a consistent speed. The car is either slowing down because of the RPM drop or it lurches ahead because she is trying to compensate by giving it more gas before the car can react. Needless to say I have traded vehicles with her until the problem is solved.

Tonight I tried something I had not tried in the past. Not sure if this helps with the diagnosis or not but, I figure there is no such thing as too much info at this point. So, while the car was acting up, I shifted it down from D4 to D3. No improvement. Still hesitating and jerking. So I shifted to neutral and gave it throttle and it came up like it was perfectly normal. Put it back into D4 and it continued to hesitate. We were approaching a stop light, so I slowed down to around 10mph, made a right and continued. The car ran normally again (as it usually does with this intermittent problem.)

After the car has run this way, the exhaust smells very strong of fuel. Also, there is a little smoke coming out from the hood but I cannot trace exactly where it comes from. Sometimes it seems like it is coming from the very front of the passenger side of the engine. Other times the smoke seems to come from the rear of the engine on the drivers side. It usually smells more electrical to me than like fuel under the hood.

We have only been getting around 280 miles per fill up. The car used to get closer to 340 per tank. Regardless of whether the car is acting up or behaving, the exhaust always smells more like gas than it used to. When it acts up the smell is much stronger.

I was passing by an Autozone so I stopped by and had the code pulled, since the Check Engine Light has been on since this problem started. But we had reset the light a week ago, so I wanted to see what the newest code was. It was P0171 indicating a lean condition in bank one, cylinder one.

As I said, this is not a new problem and has been going on for a while. We had it at a very good Honda mechanic for over a week at one point and they could not figure it out. Could not get the problem to repeat itself. Gave up and actually didn't even charge us because they were so perplexed. I believe they said the car was running too lean (or rich? sorry, I know that's important) and said they tried swapping out most every sensor but could not get the car to come into the spec properly. (I have never replaced the O2 sensor on this car (70k miles), but have been told it would not cause such substantial driveability issues.)

I have also had the EGR valve service done on this car where they also bored out the passage and inserted the tube as the TSB required.

If my memory serves me correctly, the problem started not long after we had the timing belt service done. (Same mechanic shop. A&H Honda in Delray Beach, FL. Reputable place. Not a dealership.)

As I said, I want to provide as much detail as possible in case someone sees an obvious correlation that's not obvious to me...

I have noticed that the car has had a slight oil leak from the distributer cap. About 6 months ago I replaced the distributor cap, wires and rotor. But the leak seems to be coming from within the distributor and into the cap itself, leaking out from the bottom. I have not yet replaced the distributor.

It should also be noted that we are looking to sell the car as soon as the problem is fixed, so dumping money into it is not an option.

Can anyone give me any additional advice on this thing? Since the problem is occurring more frequently now, I am thinking of bringing it back to my mechanic but hate to go in blindly, spend $100 on a diagnosis and be no better off. I hope you guys can help and appreciate whatever advice you can offer.

-Chad

 

Any ideas at all? I have it at a friend's shop today and they are suspecting O2 sensor. I am skeptical because I have not heard of O2 sensors causing such major drivability problems... Curious what you guys would suspect.

 

I don't know if this is the same thing but My 99 LX 4dr 2.3 would bogs down then come back to speed intermittantly up and down after running for awhile. I found it to be the forward oxgen sensor.

Good luck and hope you get it fixed.

 

Oil coming from inside the distributor cap indicates the shaft seal inside there is leaking. There's some sensors down there for spark & fuel timing. If it's an oily mess inside there, that could be the problem.

 

The car is still with the mechanic. He did not have a chance to look into it today. However, when I explained the problem to him, and particularly on the information that the car would run properly when shifted to neutral, his primary suspect has become the car's actual computer. ECU? He is going to look more closely tomorrow. Based on my description, he felt that the O2 sensor was not likely to cause such a problem.

If it were the distributor, why would it instantly start working correctly when shifted to neutral? The distributor would seemingly be doing the same thing as it was while in drive, so I would not think the problem would go away if that were the case. This is also a reason I am less suspicious of the O2 sensor and more suspicious of something in the car's 'brain.' Of course, I am far from an expert, just trying to logically back into this thing.

I appreciate all the help and really welcome more feedback if you have it, or arguments to any of my thoughts/diagnosis.

-Chad

 

When it's in neutral, it takes so little power to zing the engine up to high RPM, that it's difficult to tell the difference between normal & losing-power.

Still, I'm leaning away from distributor or O2 sensor for the same reasons that you said.

 

Has this car had plugs replaced, air filter replaced? It seems most frequenlty that poor drivability and failure to accelerate are ignition problems. At 156K miles, plugs are long overdue.

Check spark plug wires at night by spraying w/ fine mist of water while engine is running. Look for any sparks jumping around.

good luck

 

The car does not have any trouble whatsoever with accelration. The problem occurs when trying to maintain a speed. Today when it started acting up, I kept my foot in the exact same spot on the gas. Did not let up, did not give it more. At a stead interval or a couple seconds, the car would lose RPMs then spring back to life for a second and drop back off again. It repeated for at least 10 seconds. Then I made a U turn and it drove normal. So frustrating!!

Today, I also noticed something a little odd. Can anyone tell me why I would have oil leaking from the bolt that is immediately to the right of the plug wire to the far left? I touched it and the oil seemed very fresh. Could this have ANYTHING to do with my problem? As a side note, it is below/between this area and the header where I often see a little smoke after an "episode."

 

Pull the plug wires & look for oil down in the holes where the sparkplugs are. That would indicate a leaking valvecover gasket. That can cause some misfiring which might be the problem.

And I don't know whether you have ruled out some of the other suggestions like oily mess inside the distributor. Arcing plug wires. What kind of spark plugs (& how old)?

 

Didn't find any oil in the hole where the plug wires are. The mechanic who had the car last week recommended changing the fuel pump. He said he was able to replicate the problem, but didn't give me a lot of detail about what, exactly, he tested and witnessed. I am not willing to pay $400 for a fix that I am not highly confident in. And I just can't understand how the fuel pump alone would cause such intermiettent and eratic behavior. The car has never stalled in this process. My experience with fuel pumps is more of an all-or-nothing scenario.

I am still really eager for ideas. Please chime in if anyone knows what might be happening here.

Thanks again.