DBoy65

I have a 1965 L76 (365 hp, solid lifter cam shaft). Car starts and runs fine until it warms up. Once warm, car will stall when it is idling in traffic, stop signs etc. Once it stalls out it is difficult to restart. I replaced the older Holley 4bbl carb with newer Holley cfm 600 carb with electric choke several years ago. Current carb has under 1k logged miles on it . Old and new carb exhibited the same stalling issue. We have reset the timing, fuel mixture and idle on new carb and it is still misbehaving. Current theory is that the issue may be temp related due to metal expansion and require a valve adjustment. Has anyone else experienced this issue and if so is adjusting the valves a potential fix. Thanks!

62Jeff

Greetings,
When it stalls, have you removed the air cleaner and confirmed fuel is coming out of the squirters when you operate the throttle? Or seen fuel drippling out of the venturies (indicating fuel level too high). Have you checked for spark when it's stalled, which if found could eliminate a bad coil?

I've never heard of valves out of adjustment causing the behaviors you are experiencing.

Your symptoms sound like fuel percolation (fuel is getting too hot and boiling in the fuel bowl)

Jeff

larebob

A new Holley or an old Holley are somewhat sensitive to dirt on the needle and seat. Small amounts of fine rust can cause a fuel overload due to fuel passing by the closed needle. Get it hot at home, where you can safely stop the engine, pull the air filter and see if fuel can be seen leaking out of any part of the carb throats. Look at the rear barrels also. If the car sits a lot fine corrosion in the fuel tank may be present. As a journeyman "Buba", I even have refrigerator magnets on the bottom of the fuel tank and periodically use a magnet down the filler to sweep particles, which can come from the fuel, not always from corrosion (I have a somewhat new tank, so that isn't the source of the bits I pick up). Who knows if the GF90's are the best filters, but they look like they are big enough, anyway. BTW, our '65 is an L76, so this is real world experience.

Nowhere Man

I would make sure you're not flooding the carb when trying to restart hot. Also when it won't start making sure you have spark is a good thing to check too. Do you have points,TI or a widget

DBoy65

Hi 62Jeff, we are getting fuel and spark. No fuel dripping. We even repositioned the fuel filter thinking perhaps it was getting too hot and causing vapor lock. It has been a puzzlement so far. Thanks for your reply!

DBoy65

Thanks larebob

DBoy65

Getting spark. She has TI. Also replaced distributor cap and rotor button as part of troubleshoot. Thx

Bluestripe67

Is your vacuum advance working? Dennis

Bluestripe67

Is your vacuum advance working? If so, where is it hooked too. If not do some research about it and where to hook it. Dennis

Nowhere Man

so, you're checking for spark after it gets hot and wont restart. my statement above about flooding the carb maybe still valid. in the owners manual there is a procedure to for hot restart.

DBoy65

Thanks for all the responses! Turns out the solution was a valve adjustment. Cars running great now that we've adjusted them. They were too tight.

bg725

I was just going to jump in on this but see that you have it resolved. I had the same issue, same configuration and same resolution, adjusted to 0.30 and all is good. One thing about hot starts though, especially with todays gas, if it won't start you need to crank it with full throttle and it will start.