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I hope someone has some ideas, because I'm clean out of them.
A week ago, I drove my 96 SL2 to work. Ran great, just as it has since I got it. It was a rainy day, like many the car has sat through. When I left the parking lot, and ever since then, the engine had NO power at more than 10-15% throttle. Ran smooth at idle and very low throttle, but very rough at anything above that, causing the SES light to flash after running that way for more than a few seconds.
Replaced spark plugs and spark plug wires. No change. Cleaned the EGR valve in case it was sticking (had that problem on my 95 SC2), but it didn't stick, and didn't fix the problem.
I suspected that maybe something electrical had gotten wet and shorted out, as it was wet for a couple of days after the problem started. But the weather dried out, and the problem hasn't gone away.
Plugged in my OBD-II software, drove around a bit while a friend watched the laptop. Had a "P0300 Random/Multiple Cylinder Misfire Detected" error. While driving, we watched it add a "P0131 Oxy Sensor Circuit Lo Voltage (bank1, Sensor1)" error. That's the O2 sensor in the header/exhaust manifold.
Replaced the O2 sensor. Didn't fix the poor running problem, but after clearing the codes the P0131 never came back, so I probably avoided a future problem that hadn't gotten bad yet.
Using the OBD-II software to monitor the engine in real time, we determined that the throttle position sensor and MAP sensor were working OK. Also determined that the catalytic converter is functioning properly, as the voltage of O2 sensor #2 is significantly lower than #1 (after replacing #1).
I had the idea of disconnecting the exhaust between the header and the cat to see if maybe a clogged cat was causing all this trouble, but the header is welded to the cat, so this wasn't possible.
Removed the MSD coils. Cleaned all the contacts, put dielectric grease on all contact surfaces, reassembled. No change.
Replaced the fuel filter. (What a PITA that was). No change.
Installed an additional ground wire between the body and the engine. No change.
Filled the tank with premium (the 10.0:1 compression requires it) and added injector cleaner / octane booster. No change.
Cleaned the throttle body. No change.
During this whole process, which has taken place over the past week, I disconnected the battery overnight to reset the computer a few times. No change any of those times.
As you can see, I've tried a LOT of different things, and nothing I've tried has fixed it. I've run out of ideas. Can anybody help? I'd give up and take it to the shop at this point, except I can't afford to until I get paid at the end of this week. [img]{SMILIES_PATH}/evil.gif[/img]
A week ago, I drove my 96 SL2 to work. Ran great, just as it has since I got it. It was a rainy day, like many the car has sat through. When I left the parking lot, and ever since then, the engine had NO power at more than 10-15% throttle. Ran smooth at idle and very low throttle, but very rough at anything above that, causing the SES light to flash after running that way for more than a few seconds.
Replaced spark plugs and spark plug wires. No change. Cleaned the EGR valve in case it was sticking (had that problem on my 95 SC2), but it didn't stick, and didn't fix the problem.
I suspected that maybe something electrical had gotten wet and shorted out, as it was wet for a couple of days after the problem started. But the weather dried out, and the problem hasn't gone away.
Plugged in my OBD-II software, drove around a bit while a friend watched the laptop. Had a "P0300 Random/Multiple Cylinder Misfire Detected" error. While driving, we watched it add a "P0131 Oxy Sensor Circuit Lo Voltage (bank1, Sensor1)" error. That's the O2 sensor in the header/exhaust manifold.
Replaced the O2 sensor. Didn't fix the poor running problem, but after clearing the codes the P0131 never came back, so I probably avoided a future problem that hadn't gotten bad yet.
Using the OBD-II software to monitor the engine in real time, we determined that the throttle position sensor and MAP sensor were working OK. Also determined that the catalytic converter is functioning properly, as the voltage of O2 sensor #2 is significantly lower than #1 (after replacing #1).
I had the idea of disconnecting the exhaust between the header and the cat to see if maybe a clogged cat was causing all this trouble, but the header is welded to the cat, so this wasn't possible.
Removed the MSD coils. Cleaned all the contacts, put dielectric grease on all contact surfaces, reassembled. No change.
Replaced the fuel filter. (What a PITA that was). No change.
Installed an additional ground wire between the body and the engine. No change.
Filled the tank with premium (the 10.0:1 compression requires it) and added injector cleaner / octane booster. No change.
Cleaned the throttle body. No change.
During this whole process, which has taken place over the past week, I disconnected the battery overnight to reset the computer a few times. No change any of those times.
As you can see, I've tried a LOT of different things, and nothing I've tried has fixed it. I've run out of ideas. Can anybody help? I'd give up and take it to the shop at this point, except I can't afford to until I get paid at the end of this week. [img]{SMILIES_PATH}/evil.gif[/img]
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