Q: Do I have vapor lock, carb icing, or fuel pump issues?

asked by on

I have a 1964 Olds 98 with a 394 V8 4 bbl carburetor. After driving 25 minutes or more when I come to a stop and it is idling it will stall and when I turn the key it will start but then immediately die. After it sits for 30 minutes or more, it will start up and run with no problem for another 30 minutes to an hour, until I come to a stop again. This seems to be more prevalent in cooler temps, <50 degrees to about 35 degrees. Also, seems more prevalent with ethanol blended fuel vs. 110 octane leaded fuel. I've been told it's vapor lock but I wonder if it could be a fuel pump issue or carburetor icing. Your thoughts? Thank you so much.

My car has 68000 miles.
My car has an automatic transmission.

I think more than anything else that the multiple grades of fuel you are using is the primary source of your problem. If you use an unleaded gasoline then use a racing 110 octane leaded gasoline, it creates tons of carbon buildup on spark plug, intake and exhaust valves and intake manifold.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Do I have vapor lock, carb icing, or fuel pump issues?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My car is leaking oil i got an oil change for it last month but it is still leaking oil what will cause my car to leak oil ?

Most older cars have oil leaks. Sealing technology has just not kept up with mechanical improvements to engines so much so that leaks often kill engines rather than mechanical problems. So, it is not unexpected at all to have an,...

Q: Can't get high revs from engine. Seems choked

Depending on the HEI system you have you may have a weak coil or the carburetor is running out of fuel at the higher rpms. Use a spark tester to see if the coil is capable of sustaining the spark...

Q: Car lost all power after downshifting to go uphill

Hello! Although the Check Engine Light has been on before a new issue may have occurred, I would suggest hooking a scan tool up to the vehicle and retrieving the OBD2 codes. The problem you're having should almost certainly set...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...