Contour Enthusiasts Group Archives Forums General Troubleshooting rough idle on startup unplug maf runs smooth???

98 tour V6 start the car it rough idles wants to die , but once you drive it its fine , unplugged the maf connector start the car idles smooth car has 74k on it new plugs wires just had precats replaced . any suggestion or a fix would be great , am i looking at replacing the MAF??

Cleaning the MAF would be a good idea before replacing it.

To do that, you need to remove the screws holding the top part of the MAF in. They are tamper-proof Torx bits-- you can get a tamperproof Torx bit set at Sears.

One of the screws is covered with some sort of epoxy. I've cleaned two of these MAFs so far and each time all I could do was to use a pick to get as much of the epoxy off as I could, until I could get enough of a grip with the Torx bit to loosen the screw.

Once the screw with the epoxy is off, I then stuck it on the burner of an electric stove and turned it on, burning the epoxy out.

To clean the actual MAF, you'll need something like B12 Chemtool carb cleaner and a Q-tip.

Soak one end of the Q-tip in the B12, then gently clean both sensor wires with it. Use the other end of the Q-tip to dry the sensor wires.

Replace the MAF sensor into it's housing, and test it out. Hopefully this has fixed the problem.

Why not just clean the MAF according to the how-to article on the CEG website? You don't have to disassemble it, just remove the entire unit out of the car and spray away. MAF Cleaning

i'll try that contact cleaner , i did just clean my K&N about a month ago but the car just started acting up in the past 2 weeks

That can work if there isn't much dirt on the MAF wires, but I'll tell you--I tried that first, and then I got the idea to take the MAF sensor apart, and there was some dirt on the q-tip after I used to to clean the wires..

i took it apart and the car is still doing it..

With the MAF unplugged it's probably defaulting to richer mixture than normal. Cold start problems can be caused by a bad engine coolant temperature sensor. A bad sensor can cause the engine computer to think that the engine is warmer than it really is, causing it to not richen the mixture at cold start.

Does it only do this on a COLD start (ie, engine has been sitting for long enough to be at outside temperature) or does it do it on a warm and a cold start?

does it mainly on cold starts , i just replaced the water pump and thermostat a while ago but the problem was there before that.. but it is still rough just not as much on warm starts to id say if the starts are 10 minutes or so apart. could old 02 sensors cause this ?

No, o2 sensors are most likely not the cause of this problem. They only fine-tune the fuel mixture, and even then, they take about a minute (they need to reach 600F) to become active once the engine is started.