Bad Idle/Shaking/Misfire?? Help!
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Bad Idle/Shaking/Misfire?? Help!
Hey guys how's it going? Well let me introduce myself, I'm Damon and I'm from Orange County cali. I just picked up a 95 sc400 last weekend and it's a steller car aside from one thing.
The motor is not running right, the idle is rough, and it's not making much power... It almost seems like it's misfiring, so I replaced all the plugs/cables/rotors/caps and the problem went away but still wasn't as smooth as lexus usually are. Then I started the car again and the same problem came back in full force.. It smells sorta like gas from the back, I'm not sure if it's running rich or not.. The cats don't glow or anything and there is no check engine light. I'm not sure if OBD1 detects misfire or not? I've replaced the fuel filter as well. If anyone has any recommendations please help me out!
Car is a 95 sc400 with 197,000 miles. The plugs were pretty clean when I took them out, no sign of broken valves/headgasket from what I see
Thanks in advance
The motor is not running right, the idle is rough, and it's not making much power... It almost seems like it's misfiring, so I replaced all the plugs/cables/rotors/caps and the problem went away but still wasn't as smooth as lexus usually are. Then I started the car again and the same problem came back in full force.. It smells sorta like gas from the back, I'm not sure if it's running rich or not.. The cats don't glow or anything and there is no check engine light. I'm not sure if OBD1 detects misfire or not? I've replaced the fuel filter as well. If anyone has any recommendations please help me out!
Car is a 95 sc400 with 197,000 miles. The plugs were pretty clean when I took them out, no sign of broken valves/headgasket from what I see
Thanks in advance
#5
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I just tested the resistance on the coil pack terminals/high tension terminal and they were all within spec... I also disconnected a few of the plugs from the distributor and the idle would change with each a little (I also electrocuted myself lol.)
The car really sounds like it's missing... Could the other electronics unrelated to the ignition cause this? I guess it's possible I have a bad plug, but that seems unlikely...
#7
Lexus Test Driver
Why haven't the mods moved this to engine performance section? Need more info on running conditions,what time you drive it,do you beat on the car,other then what you have done what was the service history. Check the IACV or for a vacuum leak. No check engine light it might be along those lines.
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I would check the egr valve first , my sc3 had the same problem.... I pry open the egr valve and saw the filter was clogged solid,replace it with similar filter element reset the ecu and now it drives like a charm...GL
#9
try taking the plugs back out and look down the tube of the coilpack...clean it out with some q-tips..and such...a little moisture can cause it to short and wreak havoc on the idle.... or you can be lazy and just wait for the excess moisture to burn off...
good luck!
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