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LT1 Running Rough

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Old 07-06-2009, 09:02 AM
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Default LT1 Running Rough

I have a 96 WS6 with an LT1. About a month ago it started missing on occasion above 2500 RPM. Most of the time, however, it ran fine. Then it wouldn't start one day. I figured it was the fuel pump, assuming that it wasn't getting enough pressure and that is why it would cut out at high RPMs. So I replaced the fuel pump and while I was at it installed some Pacesetter LTs with an off-road Y and a magnaflow exhaust that I had been sitting on for awhile. Then the car started cutting out above 4000. I took it in for a tune on the dyno, and it wouldn't start when the tuner tried to work on it. A couple hours later it fired up and ran great fuel pressure. He said spark was the problem when it wouldn't fire. I got the car home and it ran like a raped ape, but a couple days later it wouldn't start. I had power to the module, but not out of the coil, so I replaced both, and it ran great for a couple days, and now it is cutting out above 4000 again. So I have a new fuel pump, new plugs, wires, module, and coil. My last resort is to replace the cap and rotor on the opti. Does anyone have any other ideas?

Thanks for the help. Adam
Old 07-06-2009, 09:39 AM
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I'm betting on the optispark.
Old 07-06-2009, 10:16 PM
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Originally Posted by adamp
I have a 96 WS6 with an LT1. About a month ago it started missing on occasion above 2500 RPM. Most of the time, however, it ran fine. Then it wouldn't start one day. I figured it was the fuel pump, assuming that it wasn't getting enough pressure and that is why it would cut out at high RPMs. So I replaced the fuel pump and while I was at it installed some Pacesetter LTs with an off-road Y and a magnaflow exhaust that I had been sitting on for awhile. Then the car started cutting out above 4000. I took it in for a tune on the dyno, and it wouldn't start when the tuner tried to work on it. A couple hours later it fired up and ran great fuel pressure. He said spark was the problem when it wouldn't fire. I got the car home and it ran like a raped ape, but a couple days later it wouldn't start. I had power to the module, but not out of the coil, so I replaced both, and it ran great for a couple days, and now it is cutting out above 4000 again. So I have a new fuel pump, new plugs, wires, module, and coil. My last resort is to replace the cap and rotor on the opti. Does anyone have any other ideas?

Thanks for the help. Adam
Post #1... Welcome!
You will probrably get better results in the LT1 LT4 Modification section. I would say Opti and or ICM (ignition control module).
Good Luck.




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