1968 Corvette 427 390HP Q-Jet Metering Rod Issue?
Hello,
I have a 1968 Corvette 427 390HP with about 1300 miles on the rebuilt matching # engine with the original Q-Jet (7028209). I had a local carb shop professionally rebuild the Q-Jet at the time of rebuild. Over the summer and into the fall I noticed that when I drive the car somewhere and run into store and come back out a few minutes later, I'll get a nice puff of smoke out of the exhaust after cranking on it for a slightly extended period of time. I took the carb back to the shop and they installed a new needle/seat and a new float but after re-installing it, the carb did the same thing again. Today, I started the car up and heated it up to operating temperature and used a flashlight to look into the air horn towards the primary throttle plates and I noticed that with the engine idling around 750 RPM, a small amount of fuel was trickling out of the driver's side main discharge nozzle and down towards the throttle plate. In taking a close look at the passenger side, I noticed no sign of fuel trickling out the passenger side main discharge nozzle at idle. In looking at a breakdown of this carb in the 1968 Chevrolet Overhaul manual, I’m thinking that maybe the fuel is leaking past the driver's side metering rod and flowing up and out the driver's side main discharge nozzle. After shutting the engine off, the fuel is probably continuing to trickle out of the discharge nozzle which in turn, floods the engine slightly, causing the puff of smoke. Please let me know what you think of this.
I have a 1968 Corvette 427 390HP with about 1300 miles on the rebuilt matching # engine with the original Q-Jet (7028209). I had a local carb shop professionally rebuild the Q-Jet at the time of rebuild. Over the summer and into the fall I noticed that when I drive the car somewhere and run into store and come back out a few minutes later, I'll get a nice puff of smoke out of the exhaust after cranking on it for a slightly extended period of time. I took the carb back to the shop and they installed a new needle/seat and a new float but after re-installing it, the carb did the same thing again. Today, I started the car up and heated it up to operating temperature and used a flashlight to look into the air horn towards the primary throttle plates and I noticed that with the engine idling around 750 RPM, a small amount of fuel was trickling out of the driver's side main discharge nozzle and down towards the throttle plate. In taking a close look at the passenger side, I noticed no sign of fuel trickling out the passenger side main discharge nozzle at idle. In looking at a breakdown of this carb in the 1968 Chevrolet Overhaul manual, I’m thinking that maybe the fuel is leaking past the driver's side metering rod and flowing up and out the driver's side main discharge nozzle. After shutting the engine off, the fuel is probably continuing to trickle out of the discharge nozzle which in turn, floods the engine slightly, causing the puff of smoke. Please let me know what you think of this.
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