Missfire bank 1

[lib]

1998 Boxster 2.5 RoW 5speed manual box.

My car has been nothing but trouble since I bought it.

It has new CPU DME unit, ignition switch, coil pack set, maff sensor, oxygen sensor over the years but it is still not fixed. I am reluctant to take it back to the main dealer as I have lost confidence in them.

I have bought a Durametric test tool and its latest fault codes are listed below.

I should be grateful for any observations that would lead to this Boxster becoming a real Porsche.

Regards Lionel.

Current Fault Codes

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P1602

Porsche fault code 660 - CAN timeout - instrument cluster

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P0102

Porsche fault code 115 - Hot film MAF sensor

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P1340

Porsche fault code 322 - Camshaft position with respect

to crankshaft bank 1 exceeds limit value

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P1319

Unknown DTC: 1319

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P1314

Unknown DTC: 1314

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P1315

Unknown DTC: 1315

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P1115

Porsche fault code 13 - Resist. limit O2S ah. of cat. conv. B1

exceeds limit value

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P1119

Porsche fault code 5 - Resist. limit O2S ah. of cat. conv. B2

exceeds limit value

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P1313

Unknown DTC: 1313

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P1585

Unknown DTC: 1585

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P1531

Unknown DTC: 1531

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P1455

Porsche fault code 170 - A/C compressor control

Open circuit

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P0134

Porsche fault code 10 - O2 sensor ahead of cat. conv.

bank 1

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P0300

Porsche fault code 507 - Misfire detection

(total)

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P0301

Porsche fault code 508 - Misfire cylinder 1

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P0302

Porsche fault code 510 - Misfire cylinder 2

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P0303

Porsche fault code 512 - Misfire cylinder 3

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[Loren]

Way too many codes - I would clear them and see which ones come back.

[lib]

Way too many codes - I would clear them and see which ones come back.

Ok Loren, Thanks

I will do that and report back

Lionel

[lib]

Way too many codes - I would clear them and see which ones come back.

Ok Loren, Thanks

I will do that and report back

Lionel

Hi Loren I have cleared the fault codes and I list below the ones that have appeared on the Durametirc.

Many thanks Lionel

Motronic 5.2.2

Current Fault Codes

________________________________________

P1455

Porsche fault code 170 - A/C compressor control

Open circuit

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P0102

Porsche fault code 115 - Hot film MAF sensor

________________________________________

P1115

Porsche fault code 13 - Resist. limit O2S ah. of cat. conv. B1

exceeds limit value

________________________________________

P1119

Porsche fault code 5 - Resist. limit O2S ah. of cat. conv. B2

exceeds limit value

________________________________________

[Loren]

P0102 says your MAF is either not connected or bad. Check the wiring and/or replace the MAF.

Clear the codes and see if the O2 sensors come back to normal (no codes).

P1455 says the AC condensor has an open circuit also. But it is not related to the engine MAF issue.

[lib]

P0102 says your MAF is either not connected or bad. Check the wiring and/or replace the MAF.

Clear the codes and see if the O2 sensors come back to normal (no codes).

P1455 says the AC condensor has an open circuit also. But it is not related to the engine MAF issue.

Thanks Loren I will check the wiring but the MAF was replaced a few months ago.

Thank you again Lionel

[lib]

P0102 says your MAF is either not connected or bad. Check the wiring and/or replace the MAF.

Clear the codes and see if the O2 sensors come back to normal (no codes).

P1455 says the AC condensor has an open circuit also. But it is not related to the engine MAF issue.

Thanks Loren I will check the wiring but the MAF was replaced a few months ago.

Thank you again Lionel

Hi Loren

I have carefully checked the wiring to the Maf sensor and there is continuity in each wire, no shorts and no earths.

I have 5volts between term, nos. 4 and3,and

12volts between term. nos. 5 and 3

The resistance between term.1 and 3 is 2700. on the maf itself.

The maf was replaced a few months ago in a attempt to resolve this problem.

The Bosch number on the new maf was 0 280 217 007

Any help solving this issue would be much appreciated

Thanks Lionel

[Loren]

Pin 1 is the air temperature sensor signal.

The air flow signal is on pin 3.

You will the Durametric software, a PST2 or PIWIS tester to read the actual air flow across the MAF (to determine if it is working).

Readings are in Air mass ML in kg/h

Idle - 12 -24

at 2500 RPM (no load) - 40-70

If you don't get these readings (or close to them) then the MAF is likely bad.

[lib]

Hi 5700ci

I am sorry, you have reminded me that I should have put some feed back on my post.

Oops sorry again.

Yes the problem is now cured. There were two problems that I discovered I am not sure which was the culprit.

The first was the valve timing. I decided to remove the plastic plugs in the camshaft covers and remove the oil scavenging pumps from the camshaft covers.

I then rotated the engine with the crankshaft nut to align the cam shaft marks.

The Durametric tester indicated that the misfire was on bank 1 so I decided to move the adjustment by moving the gear on the camshaft slightly towards the center of the elongated slots in the gear as the bolts were to the extreme left in the slot.

This brought the timing marks into alignment.

I can only assume that whoever owned the car before me had done some work to it but it had not been done correctly.

I am not sure why the misfire only showed up on tick over when the engine was hot????

The second problem I found when I was checking out the valve timing, and which I hadnt heard before, was when I switched the engine off there was the sound of a bearing or gear still spinning down.

I thought it must be the clutch release bearing, so I removed the gearbox to change it.

I discovered that the flywheel was in two separate pieces. The center rubber cushion of the dual mass flywheel had completely broken up and there was no signs of bits in the housing, its a mystery!!!

I wonder how it drove with no symptoms like the clutch slipping or jerking.

The thought is whether there was an imbalance in the engine that was detected by the sensors and the ECU tried to compensate for it causing the engine to run rich and cause a misfire.

Regards lib.