Runs rough. What happened?
09-05-2017, 10:30 PM
#1
Rennlist Member
Thread Starter
Runs rough. What happened?
I have a fairly new-to-me 2002 Boxster base with the 2.7 and 223,000 miles. While sitting at a red light yesterday, the car died and siunded very odd when trying to crank it. I was afraid maybe I was experiencing an IMS failure. I pushed it out if the road and after a couple of minutes tried it again and it started but ran very rough. I drove it home with the cel on and it periodically flashed. I checked the codes when I got home and had: p300,301,302,303, and 343. It will still start but runs rough. Anybody experience anything like this? Where do I start? Could it be as simple as a wiring issue with the cam position sensor or a bad sensor?
09-06-2017, 04:59 PM
#2
Drifting
From your info it seems that a search for a competent ,honest Indie may be the best plan. The codes are easy .The correct diagnosis and repair is a different story. Search those codes here for more.
09-07-2017, 12:15 PM
#3
Race Director
I have a fairly new-to-me 2002 Boxster base with the 2.7 and 223,000 miles. While sitting at a red light yesterday, the car died and siunded very odd when trying to crank it. I was afraid maybe I was experiencing an IMS failure. I pushed it out if the road and after a couple of minutes tried it again and it started but ran very rough. I drove it home with the cel on and it periodically flashed. I checked the codes when I got home and had: p300,301,302,303, and 343. It will still start but runs rough. Anybody experience anything like this? Where do I start? Could it be as simple as a wiring issue with the cam position sensor or a bad sensor?
P0343, the out of reference book version:
P0343 Camshaft Position Sensor 1 – Above Limit
Potential causes:
– Short circuit to B+
Check the connector/wiring.
Check signal wire from DME control module, pin III/20, to CMP sensor for short circuit to B+.
1. Connect special tool 9637 to wiring harness (DME control module connector).
2. Remove connector of CMP sensor.
3. Connect voltmeter to special tool 9637, pin III/20, and ground.
Switch on the ignition.
Display: 0 V
If battery voltage is displayed, check wiring harness for chafing and pinching damage.
However, unless you are a pretty experienced automobile DIY'er the above won't help you much.
More than likely when the source of the P0343 error code is found and fixed the misfires will go away. The misfires can arise because the cam timing is not correct. The DME will adjust fueling to try to get the O2 sensor readings it expects and in doing so will adjust the fueling too far and misfires result.
You can see this if you monitor the engine telemetry with an OBD2 code reader/data viewer. The bank #1 short term fuel trims are probably all going crazy as the DME tries to find the fueling adjustment that works.
Schnell's recommendation for a good indy, and I would add or a dealer tech, would be your best bet.
A tech at a local Porsche dealer resurrected my 2002 Boxster engine when the passenger bank VarioCam solenoid/actuator went bad and while the engine did not misfire as I observed the short term fuel trims with my Actron OBD2 too the one for the passenger cylinder bank was doing the crazy thing.
Best to avoid running the engine any just get the car flat bedded to someplace where the problem can be diagnosed and fixed. Might add my 2002 Boxster had the VarioCam solenoid/actuator replaced at over 250K miles and the engine now has around 315K miles and has been fine ever since.
09-08-2017, 10:13 PM
#5
Race Director
The tension pads on the actuator of my Boxster's passenger bank were not worn all that much even at around 250K+ miles. I talked to the tech and told him if in his opinion of the pads were worn too much that he was free to replace the pads (at least and I would have sprung for a new solenoid/actuator if necessary) on the other side. He said the pad wear was really nothing and as long as the other bank was not generating any error codes like the passenger bank did to leave the other bank alone. 50K+ miles later the other untouched bank (and the repaired bank) are fine.
In the OP's case as long as the filter element and oil filter housing oil show no signs of any composite plastic material (the aluminum rails are protected by plastic which is what the chains run/rub against) or worse lots of aluminum "metalflake" which is what the chains make when the chain begins to make contact with the aluminum rail/guide (which would mean the plastic is severely worn or even missing) I'd hazard a guess all is well in that department.
'course the OP is encouraged to get a professional tech's opinion.