93 LT1 will not accelerate, cats glowing, no codes
Thread Starter
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Joined: Dec 2005
Posts: 98
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From: Titusville Florida
93 LT1 will not accelerate, cats glowing, no codes
Working on a 93 LT1 auto. that starts fine cold, hard staring warm, idles fine and runs fine at 2000rpm. It is getting it to rev that is the problem. There is a point just off idle that it stumbles, backfires and sometimes cuts off. When in gear it will not accelerate even with accelerator to the floor. The cats turn red after less than 10 minutes idling. There are no codes except DIC 67 A/C code which went away on its own. Have checked, Opti (new), coil, ignition module, ECM, Fuel 48 psi, new FP regulator, MAP ok, TPS ok, fire at coil and plugs, engine temp is 196, oil temp 192, new fuel pump, filter and relay. Tested with a Vetronix Master Tech.
Don't know where to go next.
Need help!
Don't know where to go next.
Need help!
Race Director
Joined: Oct 2005
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From: Rolla Missouri
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The symptoms your describing can be caused by clogged cats.
The engine will start and run just fine and even rev while stopped.
But put any load on it (like actually trying to drive), and you have no acceleration.
The engine will start and run just fine and even rev while stopped.
But put any load on it (like actually trying to drive), and you have no acceleration.
Racer
Joined: Jun 2006
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From: SANTA CRUZ CA
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the cats are turning red for a reason. better find out why before replacing them. Is this car have a a.i.r. pump and is it working? do you have a fuel injector stuck on? What do the O2,s look like I do not want to see you spend money on new cats just to have the same problem
Race Director
Joined: Apr 2000
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From: Texas
the cats are turning red for a reason. better find out why before replacing them. Is this car have a a.i.r. pump and is it working? do you have a fuel injector stuck on? What do the O2,s look like I do not want to see you spend money on new cats just to have the same problem
Thread Starter
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Joined: Dec 2005
Posts: 98
Likes: 1
From: Titusville Florida
Thought about cats, but it revs freely once it gets over the stumble just over idle. The only thing that is showing a little off norm is Idle Air Control is 100 and injector pulse width is 4.5 and 4.7. O2 sensors are reading 204-825 (Bank 2) and 226-825 (Bank1) has gone into open loop.
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