Join Date: Jan 2000
Location: Island Lake, IL
I have a ZZ502 in a ’69 Camaro that has run more or less trouble free for the past three years. This season has started with a problem that I just cannot seem to isolate.
At water temperatures between 180 and 200 degrees, the engine seems to flood out and stall. It is very repeatable. I get a strong fuel smell out the tail pipes, but no black smoke. Sometimes I can feather the engine through it, other times the engine just dies. I have to wait until the engine cools down below 180 degrees before it will start and run smoothly again.
I have tried two different carbs (a BG 850 Vac Secondary, and a BG 850 Vac Secondary with annular discharge boosters). I have also tried two different coils, two different coil wires, and two different distributors (MSD). I have checked the fuel filter and float bowls for debris, and they were clean. The gas tank itself is brand new (3 years old). When I changed carbs, I changed spark plugs.
The one common thing between the two systems are the plug wires (MSD), but these are only a year old.
I cannot seam to find what is breaking down with temperature, or what would cause the flooding condition. Everything I can measure so far remains constant between running smooth and the stumbling/flooding condition.
When the engine starts to stumble, vacuum remains solid (idle vac. is 12”), timing remains steady, voltage to the coil remains steady (12 – 13.5 volts), and fuel pressure remains steady (6 lbs.).
Any ideas? Has anyone had this problem before? I am running out of things to try.
Thanks and Regards!
'69 RS/SS Camaro 502/TH400/4.11 Best 12.10 @107mph
'69 Z/28 Clone 383/TH400/3.73 Done! 996 Points out of 1000 at MCACN 2009
'72 Chevelle 540/TH400/4.11 Best [email protected]
137mph - 11/07/10