HELP, HUSBAND OUT OF TOWN! ENGINE IS MISFIRING IDLING AND DRIVING. HAD A TUNE UP WITH NO HELP. ANY SUGGESTIONS WOULD BE APPRECIATED AT THIS POINT. TRIES TO BACKFIRE WHEN ON HILLS. BAD EXHAUST SMELL IN FRONT AREA OF VEHICLE.
HELP!HELP!HELP!

 

What items were replaced during the tune-up? Explain further your statement "tries to backfire when on hills". (Would engine bucking be a more apt description? i.e. a series of rapid, start/stop convulsions) Any smoke, white or black visible from the tailpipe when you notice the smell? Does the engine misfire constantly at idle and while driving or only intermittently? Does it start easily?

Lots of questions but they will help narrow the focus for better assistance.

 

HI AEROCOLORADO, I HAVE A 3.0 6CYLINDER, 160K MILES, WIRES AND PLUGS WERE REPLACED AND DISTRIBUTER CAP, PCV VALVE, DISTRIBUTER CAP, ENGINE CONSTANTLY MISFIRES(ROUGH IDLE AND DRIVING). IT SOUNDS LIKE IT IS SENDING AIR BACK OUT THROUGH THE AIR FILTER(SOMETHING LIKE BACKFIRING), SEEMS TO SMOOTH OUT ON ACCELERATION AND DECELERATION.
I HAVE FOUND A DETERIORATING VACUUME LINE COMING FROM PCV VALVE TO AIR FILTER(COULD THIS BE THE PROBLEM).........NO CHECK ENGINE LIGHT ON. STARTS OK, SOME TIME HAVE TO GIVE SOME GAS NOT ALWAYS. WONDERING IF THIS COULD BE CATALYTIC CONVERTER PROBLEM(HAS 2). JUST FROM LISTENING TO IT MY STEP-FATHER SAYS HE THINKS IT IS A BROKEN VALVE SPRING(HOPE NOT).
ANY HELP APPRECIATED, THANKS
PS: CANNOT SEE ANY SMOKE

 

HOW DO YOU GET THE MAF SENSOR OFF TO CLEAN?

 

The initial thought was vacuum related and this still makes the most sense. Check the vacuum 'octopus', the multi-ported vacuum tree on top of the engine toward the rear. You may have to open the interior access door for a better view. All these should either have lines attached or be capped off. There have been many reports of the lines or caps deteriorating and coming loose. Your problem sounds suspiciously like a line is off.

Cleaning the throttle position sensor (TPS), idle air control valve (IAC) and the mass air flow sensor (MAF) is a good idea as it solves many common problems and is cheap and easy to do.

Before doing the following, disconnect the negative teminal on the battery for at least 10 minutes. This allows the engine computer to reset itself.

The MAF is located just after the air cleaner box on the air tunnel. It is held on by two Torex screws. Disconnect the electrical connection, remove the screws and CAREFULLY pull the MAF sensor up and out. There are delicate wires on the sensor. Spray these several times with an areosol electronic cleaner and replace.

The IAC is located on the side of the throttle body, a metal cylinder with an electrical connector, held on by two bolts. Remove and spray with carb/choke cleaner several times on the end going into the throttle body. Reattach, no calibration necessary.

The TPS sensor is also on the throttle body, a black round affair near the front of the throttle body. Again, with an electrical connector. Remove and spray clean with electronics or carb/choke cleaner.

Reconnect battery and start van. With the computer reset, it may take a day or two of driving before the system 're-learns' your driving chacteristics and adopts the optimal engine settings.

Hopefully one of these will solve the problem before hubby comes home. This is beginning sound like an old 'I Love Lucy' program........."Lucy, you got some... 'splainin to do!"

 

LOL, THANKS FOR INFO. WILL LET YOU KNOW.
DAYLIGHT(DAWN)

 

HOW DO YOU GET THE MAF SENSOR OFF TO CLEAN?

Aerocolorado (listen to him,he knows his stuff) mentioned the Torx screws on your MAF sensor,not sure but they might be the security type (pin in the center) like I have on my 4.0 engine. If they are,I was able to pick up a whole set of driver bits for the outrageous price of.....$3.99 at ABC Discount Auto. :^)
Good Luck!

 

My MAF screws have their torx ends filled with epoxy (grrrr!) so what I had to do was take the entire MAF housing off (with battery disconnected of course) and spray the cleaner into the housing and where the MAF wires are.