1994 chevy 2500 2wd with 350 tbi

[nicodemus]

Hi, I am wondering if any one can help me out with my truck. It is a 1994 chevy 2500 light duty, 2 wd. I have had the truck for 17 years, and it has been a great work horse. 3 years ago, my transmission finally packed it in, so i figure with 400,000 km on the motor it was time for a rebuild. I installed the new engine and everything was fantastic, great idle, fuel economy, just like new again. About a year later i experienced a no start condition, which i traced to the distributor, and replaced it with a brand new unit. The truck fired right up but ran with a heavy idle, just like a highly cammed race motor. I adjusted the timming to 0, with the plug disconnected, still no difference. So I pulled the distributor and put the motor to TDC and reindexed the distributor, no change. I have tried this probably 10 times over the years. The truck still had tons of power and ran great accept for the lumpy idle, never stalling people just though it was a sleeper with a monster under the hood. It rocks the truck at idle just like my 468 in my Chevelle does with its heavy cam.

Recently it started running hugely rich, smoking so bad that everyones eyes water. I have replaced the O2 sensor, CTS, Thermostat, IAC, PVC, even swapped the injectors from a parts truck. I recently removed the intake and reinstalled it with a distributor from the parts truck. Still no luck, heavy idle, smoke like crazy, but still tonns of power. The new motor only has about 30,000 km on it now. I am about to pull it back out to figure this out. I dont know if the timming jumped a tooth or what.

Any help would be appreciated, thanks.

 

[SAATR]

It sounds like you're getting too much fuel at idle, which would make sense with the smoking and heavy fuel smell of the exhaust. It is possible that the FPR is ruptured, though I would think that the engine would misfire and misbehave a little more than just a choppy idle. When you pulled the intake and replaced it with the intake from the parts truck, did you also use the throttle body from the parts truck? Are the plugs fuel fouled when you pull them out? You may want to check the fuel pressure and see what exactly is going on.