1968 Strange First Start After Sitting >48 Hours
Hello,
I rebuilt my Holley Carb; see all specs below. If I leave the car sitting for over 48 hours, I get a sort of "whoshing" sound which seems to come up through the carb on ONLY the first start attempt. The car does not start but on the 2nd try it does start. Once I left the car for 30 days without starting it and it actually backfired on the 1st attempt. On the 2nd attempt, the car will usually start, no problem. If I purposely stop the car, I can start it again no problem. In fact, it can easily start even if I only give a short click with my key and no gas peddle. After the car is started, engine is essentially smooth (for a 15 year old engine). Vacuum stays at 17-17.5 (moves very slowly from 17 to 17.5). Acceleration is very smooth and nice from 0 to 60, no problem. It's only that 1st start after sitting for over 48 hours which is bad.
I checked the float levels through both bowl ports and the sec. bowl seems to drop by 5mm after 48 hours. Could it be that fuel is dropping from the sec. bowl and is causing this problem? If so, why is the sec. bowl leaking and how can I fix it?
During the carb rebuild, I replaced the intake manifold gasket with a FelPro 1250, and also replaced a bent pushrod. I adjusted the rocker arm nut and there is no "ticking" sound" I'm just writing this for completeness.
I'm not exactly sure what is causing the problem. Does anyone here have a lot of Holley expertise who can tell me what's going on? I had to rebuild the carb because I could no longer even start the car. Before not being able to start it, it would be hard to start. If went on a short trip, after I returned to the car, there would be a noticeable gas smell coming from the carb. Eventually I could not start it at all, so I rebuilt it. See my engine and Holley specs below:
1968 Ford Mustang
302 Engine with stock type cam.
Edelbrock Performer Aluminum Manifold.
Holley model 6919, type 4160. Vac. Sec., Sec. plate.
___The Holley was purchased in 1988
___Power Valve 9.5" (which closely matches my car)
___Purple (medium-light) Sec. spring
___Primary Jet is a 62
___Sec. Plate is #39
___Accel. pump is a 30cc with a white cam in #2 position.
___Accel. discharge nozzle is a 31.
Headers
Mallory Electronic Distributor
Hello,
I rebuilt my Holley Carb; see all specs below. If I leave the car sitting for over 48 hours, I get a sort of "whoshing" sound which seems to come up through the carb on ONLY the first start attempt. The car does not start but on the 2nd try it does start. Once I left the car for 30 days without starting it and it actually backfired on the 1st attempt. On the 2nd attempt, the car will usually start, no problem. If I purposely stop the car, I can start it again no problem. In fact, it can easily start even if I only give a short click with my key and no gas peddle. After the car is started, engine is essentially smooth (for a 15 year old engine). Vacuum stays at 17-17.5 (moves very slowly from 17 to 17.5). Acceleration is very smooth and nice from 0 to 60, no problem. It's only that 1st start after sitting for over 48 hours which is bad.
I checked the float levels through both bowl ports and the sec. bowl seems to drop by 5mm after 48 hours. Could it be that fuel is dropping from the sec. bowl and is causing this problem? If so, why is the sec. bowl leaking and how can I fix it?
During the carb rebuild, I replaced the intake manifold gasket with a FelPro 1250, and also replaced a bent pushrod. I adjusted the rocker arm nut and there is no "ticking" sound" I'm just writing this for completeness.
I'm not exactly sure what is causing the problem. Does anyone here have a lot of Holley expertise who can tell me what's going on? I had to rebuild the carb because I could no longer even start the car. Before not being able to start it, it would be hard to start. If went on a short trip, after I returned to the car, there would be a noticeable gas smell coming from the carb. Eventually I could not start it at all, so I rebuilt it. See my engine and Holley specs below:
1968 Ford Mustang
302 Engine with stock type cam.
Edelbrock Performer Aluminum Manifold.
Holley model 6919, type 4160. Vac. Sec., Sec. plate.
___The Holley was purchased in 1988
___Power Valve 9.5" (which closely matches my car)
___Purple (medium-light) Sec. spring
___Primary Jet is a 62
___Sec. Plate is #39
___Accel. pump is a 30cc with a white cam in #2 position.
___Accel. discharge nozzle is a 31.
Headers
Mallory Electronic Distributor
