Skip the auto shop - Our mechanics make house calls

Q: Swapped carburetor and the engine stalls out.

asked by on

Hi, I need some help. I have a 1973 350 Chevy motor which had an old Edelbrock 4 barrel carb. that hesitated and backfired a lot. I found a rebuilt 1973 Rodchester Quadra-jet for a good price, so I swapped out carbs. The Q-jet starts her and idles her smooth and strong, but the second I try to put it into gear she kills, even when allowed to fully warm up. The other carb. would let it run in gear once warm. Plus, I get a double whammy when she dies hot. Hedder heat retards my starter even with a shield wrap. Then it won’t start until she’s cool again. There’s no idiot lights and I can’t scan for check engine codes because this motor was dropped into a 1982 El Camino and I don’t think any of that was set up. Any suggestions to make run in gear would be greatly appreciated. She’s what gets me to work and back daily-(was). Thanks in advance, Tom

A: Hi there. When you swap out carburetors on...

Hi there. When you swap out carburetors on engines, you would have to set up the carburetor and adjust the float bowl along with setting the idle. With a Rodchester Quadra-jet, you would need to have the engine idle at 850 to 950 rpm's in the park and neutral positions and 650 to 750 rpm's in the drive or reverse position. Also, when changing out the carburetor, the timing will need to be adjusted with an advance. This is for the massive air jets when snap throttling the Rodchester Quadra-jet. Plus, make sure that all of the ports to the carburetor that are not used is plugged off if there is a vacuum on the port. If you need further assistance with adjusting your carburetor to keep the engine from stalling, then seek out a professional, such as one from Your Mechanic, to help you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car idling really high and stalling

Hi, Yes, the carburetor could have an issue in the choke linkage which would keep the choke open more than normal. The choke helps the engine warm up by keeping the throttle plate open and allowing more air into the...

Q: Truck keeps stalling and won't start

Hi, thanks for writing in. A vehicle that cranks normally but doesn't start generally indicates a lack of spark or fuel. The first thing to do is check for diagnostic trouble codes as these codes serve as starting point for...

Q: Truck accelerated past 35 and started sputtering

Hello there, thank you for asking about your car. The first thing that comes to mind is a secondary ignition misfire (spark plugs, wires, etc.). An ignition misfire is most noticeable under load and can be felt as a shudder...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.