Hello,

1973 Hurst Olds mostly stock, restored in the 90s

I want to get the car to not be such a hassle to get started and going. If the car sits a while, even just a week, it takes 5-10 minutes of pressing the gas pedal and "warming" the car up before it will idle without stalling. It takes even longer than that before I can put it into gear without it immediately stalling. Once it's finally warmed up it runs fine and can start/stop the rest of the day no problem.
Spraying starting fluid into the carb will keep it from stalling

A relative of mine thinks it's the carb, considering the bad reputation Quadrajets get. What are your guys thoughts

And if it is the carb:
- Are there aftermarket options that look stock that would perform better? I'd keep the original carb on the shelf or see if there's a place that can rebuild and drive with the aftermarket

Thanks

 

He's right...

I had similar issues with my then new remanufactured Rochester Quadrajet replacement. When I purchased the car it came with several cans of starter fluid and a replacement battery due to the hard starting. Nothing better for an Oldsmobile than the Rochester, but they need proper adjustment. Sounds like your choke needs attention, as well as air fuel mixture, and possibly fuel delivery issues...

 

Sitting for a week causing a hard start is normal. If you want an easier start, fill the bowl with fuel through the vent tube prior to starting. The rest of the running issues may be due to needing a tuneup.

 

Welcome, post some pics of your ride.

Does it start ok if it sits for one day, two days...?

Quadrajets are very good carbs, like anything else they need to be set-up properly. I've seen many Q-jets that start and run almost like fuel injection. They have several adjustments which must be done properly, stick with the Q-jet especially if it is the correct one for your mostly stock car.

 

It should not take that long. It didn't take that long when they were new. I would first install and electric choke. The carb can probably use a rebuild. When was the last time the car had a good tuneup?

 

If it is requiring long cranking times to fire up after sitting long, this could be due to the fuel in the line slowly siphoning back into the tank. After it does that, it takes awhile for the fuel pump to suck it back up to the engine from the tank. Not uncommon.

Seems the long warm-up-until-its-ready-to-drive issue could be related to the choke not shutting properly when "primed" to start up. Make sure the choke mechanism on the carb moves freely and doesn't bind (especially when cold).

 

The problem is that gasoline evaporates. When these cars were daily drivers, this was not a problem. When they are only driven every other week or so, it is noticeable. Cranking the engine refills the carb float bowl. Unfortunately today people only drive EFI cars that have an electric pump that primes the system. The warm up to avoid stalling problem is the choke. Likely the thermostatic coil needs to be replaced. They do get weak with age. When was the last time the carb was rebuilt. Do NOT replace the carb with a generic rebuild or aftermarket. That will only bring more problems unless you have the skills and patience to properly change jetting to match your specific combo.

 

If the carb hadn’t been touched since the 90s, I’d start there.

As Joe mentioned, fuel evaporates. Today’s fuel is even worse. Back when cars were carbureted, the refineries used additives to prevent fuel evaporation. Since the vast majority of fuel buyers today drive cars with EFI, those additives were an unneeded expense in the eyes of the bean counters.

Another issue: today’s fuel sucks. It attacks rubber materials, and attracts moisture from the air. Try to use non ethanol gasoline. Get a GOOD quality carb kit from Cliffs High Performance, his carb kits are top notch and tolerate todays fuel.

Fix the carb that’s on it, don’t bolt on more headaches with a aftermarket.

 

I agree with Matt. If nothing else, get a new accelerator pump and anti-siphon fuel filter for starts. Of course you will need the top plate gasket as well..
MAW put a whole kit in.

 

I'm rebuilding a Q-Jet 7043251 currently. I ultrasonically clean the carb, put in a new accelerator pump/needle-seat along with the gaskets and other items that come with a rebuild kit. I also drill out the primary shaft and install bushings for a tight seal and seal the plugs that can lead to hard starts. I replace the power piston retainer bushing and have 70 jets and 53C primary metering rods for this carb, which I believe is set up for a 455 engine. I also install a new fuel filter in the carb, then test it on my engine stand, which is a 350 SBC. Let me know if you'd be interested in this when done, or have any questions in the meantime.

 

Thanks everyone for the replies! Looks like consensus is start with a carb rebuild.

Here's a dumb question for everyone: Does rebuilding the carb with say a kit from Cliffs change the "stock" value at all?

And then another question, what is the difficulty level of a rebuild? To be honest I am not very familiar with carburetors, is there any good material/guides on a rebuild? Or should I leave this to a professional?

I would definitely be interested. PM me with details. One question though: the last digit being a 1 shows it being for a manual transmission. I have an automatic, does it matter?

 

PM sent.