986 3.2s missfire

[dave364634]

What's it likely to be? There is like a slight delay when you dab the throttle, and it sort of gets better at 4,000 then 6,250 rpm.

The oil level is slightly overfull, but it has been for a month (full service).

There is no engine light on the dash.

Ta.

 

[Motorhead]

Dave,

Missfires are usually attributed to the coil packs, so it's worth looking at them and the plugs too.

Other possiblities for hesitancy? - electronic throttle, resonance intake manifold or MAF malfunctions perhaps, but with so much complex electronics on board you're best getting a diagnostic check.

Regarding your other post on engine upgrades, the size of the air filter was increased significantly on the 987 but it's unlikely that the unit is downward-compatible. A plenum upgrade is available from IPD ( http://www.ipdplenums.com/index.php?option=com_content&view=article&id=12&Itemid=15 ) and Design911 offer various tuning packages for your car ( http://www.design911.co.uk/fu/pt57_697_1663_-cma81-cmo82/Porsche/Boxster-986-987-981/Performance-Plenum-IPD/ ).

Jeff

 

[glewis]

I had a similar problem on a 986 Boxster S I had a few years ago and it turned out to be a combination of two cracked ignition coils and a faulty MAF sensor -luckily all replaced under extended warranty by OPC Nottingham.

 

[T24RES]

Unplug the maf sensor tie it out of the way. If it drives fine thats your problem. It will default to a base setting, but not pass emissions.

http://www.pelicanparts.com/techarticles/Boxster_Tech/27-FUEL-Mass_Air_Flow_Sensor/27-FUEL-Mass_Air_Flow_Sensor.htm

 

[dave364634]

I plugged it in and got 0103 Mass Air Flow Sensor - Above Upper Limit.

The g/min reading went up and down when I revved it.


So can I clean it, or do I have to swap it? Does anything other than a faulty MAF sensor cause the reading?


-----

Also my oil is perfect on the dipstick, but read high on the dash. Is this normal?


Ta.

 

[Motorhead]

ORIGINAL: dave364634

Does anything other than a faulty MAF sensor cause the reading?

Richard H can probably give you a definitive answer to this Dave.

Although it is possible to purchase cleaning solutions for the MAF, probably it's best to replace the item rather than attempt to clean it, particularly if your car has covered a fair mileage.

Also, I'd believe the dipstick oil level. Maybe there's a problem with the sensor which is giving you a false gauge reading.

Jeff

 

[dave364634]

I reset it the other day, and it all seems fine again.

 

[BartyB]

If you plan to clean the MAF sensor, a non-residue contact cleaner such as Isopropyl Alcohol or Hexane seems to work best as, unlike white spirit, paraffin, drain cleaner, the Mrs' face cleanser, Daz, Cillit Bang, etc., they won't damage the delicate coating that is applied to the surface of the MAF element.

Disconnect and remove the MAF sensor. Put it in a zip lock bag with a few ccs of the alcohol added. Seal the bag and gently agitate the alcohol inside the bag, making sure it flushes across the wire sensor element, for a few minutes. Remove the sensor, put it somewhere safe to dry for about an hour then re-fit.

 

[Timbo2]

Just cleaned my MAF, and the car drives so much better, I'd forgotten how well. My advice would be to buy a specialist MAF cleaner, and dont do anything other than spray the MAF. I did this over a white bowl to see how dirty it was and to be honest not that much came off, probably enough to cause the hesitancy I was getting. Incidentally, all my coil packs show cracking on the outside and have been like that for years with no problem, I think the problem arises when the inner part which deals with HT voltages cracks.

 

[dave364634]

I sprayed it with electrical cleaner and reset the ecu. No problems yet.

 

[spyderman]

ORIGINAL: Motorhead
Regarding your other post on engine upgrades, the size of the air filter was increased significantly on the 987 but it's unlikely that the unit is downward-compatible.

The 550 Anniversary was used as a sort of production test bed for the 3.2 987, so some 987 intake components definitely fit. Don't forget both are M.96 engined.

Chris.