Hard to start after a week

[76Stingray]

My 1976 Stingray is only allowed out of the house on the weekends, so after a full weekend of driving and tinkering with no starting issues whatsoever, she sits in the garage and rests until Friday night comes around. I have to pump the gas and crank the engine many many times before she fires up. Once she's started that first time, I never have any problems the rest of the weekend. She always starts right up on the first crank. What's going on here? What is happening over the course of five days that makes it hard to start on Friday nights? All that cranking isn't good for the starter, battery, etc... I have had several suggestions ranging from the fuel pump to the carbuerator. Any advice from someone that has actually had the same problem would be greatly appreciated.

 

[JohnZ]

Sounds like the chronic Q-Jet carb float bowl drain-down problem, caused by loose/leaky plugs in the bottom of the float bowl. If you pull your oil dipstick, does it smell like gasoline?

 

[petes74ttop]

That's normal!

Hi 76Stingray and welcome again. The Q-Jet carbs let the fuel evaporate when your car is parked and it takes a few seconds of cranking to refill the carb after it sits for a week. You might want to check the adjustment on the choke. We are spoiled with the computerized systems on our newer cars that start every time no matter how long they are parked. PG.

 

[DRTH VTR]

Sounds like the chronic Q-Jet carb float bowl drain-down problem, caused by loose/leaky plugs in the bottom of the float bowl. If you pull your oil dipstick, does it smell like gasoline?

76Stingray

Pay close attention to what JohnZ has to say. He knows these cars like nobody else.

 

[Vettehead Mikey]

The Q-Jet carbs let the fuel evaporate when your car is parked and it takes a few seconds of cranking to refill the carb after it sits for a week. r

Sorry to disagree, but my car has the original Qjet it came with in 1973. I can let it sit for 6 months untouched and it will start up immediately.

There is something else going on- not a factory design defect.

 

[petes74ttop]

This issue involves several problems.

On a Q-Jet the needle/seat are at the bottom of the carb on the same elevation as the accelerator pump slot. If the fuel level drops to low the accelerator pump will not function.
A cold engine will not start on the choke alone, it needs a accelerator pump shot.
How can the fuel level drop?
It can leak fuel from the bottom at the well plugs.
Fuel can evaporate thru the vent tube.
Fuel can also drain out the needle/seat and back down the fuel lines.
PG.

 

[GaryS]

Sorry to disagree, but my car has the original Qjet it came with in 1973. I can let it sit for 6 months untouched and it will start up immediately.

There is something else going on- not a factory design defect.

If you do any searches on the subject, the Q-jet plug issues come up a lot, just like John says. The fact that yours doesn't shouldn't be looked upon as a way to discredit JohnZ. More like an anomaly (sp?) than the norm. There have been lots of reports that guys seal these with two part epoxies, like JB Weld.

Fwiw, my 72 LT-1, with original but restored Holley, does the same thing. I crank it for 5-10 to get fuel to the carb; shut off the ignition, pump the gas a time or two and it fires right up. If I drive the car throughout the next day or two, it fires immediately. If I let it sit for more than a week, the bowls drain.

 

[Vettehead Mikey]

. The fact that yours doesn't shouldn't be looked upon as a way to discredit JohnZ.

There was no intent to discredit John.

Please re-read my post in the context of disagreeing with the poster I quoted who inferred that this is normal behaviour for Qjets- in other words something that we all just live with. He specifically entitled his post 'That's normal' which is not correct, hence my comment that there's something else going on.

John, if you feel slighted in any way I'll make sure that AC sets you up with an additional hummer at Carlisle.

 

[JohnZ]

John, if you feel slighted in any way I'll make sure that AC sets you up with an additional hummer at Carlisle.

Mike, I don't feel slighted at all - I understood your post. However, now that I've trained AC to make them correctly and don't have to make my own any more, an extra one would be nice .

 

[Vettehead Mikey]

Mike, I don't feel slighted at all - I understood your post. However, now that I've trained AC to make them correctly and don't have to make my own any more, an extra one would be nice .

With apologies to the OP for going off topic, I note that Brian is sitting with an empty cup again. AC's training apparently still needs work. This is what it looks like when all goes to plan:

 

[76Stingray]

Sounds like the chronic Q-Jet carb float bowl drain-down problem, caused by loose/leaky plugs in the bottom of the float bowl. If you pull your oil dipstick, does it smell like gasoline?

I just pulled the dipstick and checked it this morning and my somewhat novice assessment would be that there is a slight hint of a gasoline smell on the dipstick, but not overwhelming. If draindown is my problem, what is your recommendation for the most effective long term fix. I'm not a fan of 'live with it' as I'm sure the original owner in 1976 didn't have to deal with this.

 

[petes74ttop]

First step is to confirm that the well plugs are leaking or not, pull the carb and put it on blocks on your work bench, then pour 1-1/2 oz of gas down the vent tube. If the plugs leak a permanent fix is to drill and tap a 10-32 hole and install a 10-32 countersunk screw. Coat the threads with JBWeld prior to installation for a permanent fix. PG.