How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask roy Your Own Question
roy, import/domestic specialest
Category: Ford
Satisfied Customers: 6163
Experience:  ASE master tech for 40 years
Type Your Ford Question Here...
roy is online now
A new question is answered every 9 seconds

I have a 1974 Ford F100 390 V8 2 bbl carb. I have hard

This answer was rated:

I have a 1974 Ford F100 390 V8 2 bbl carb. I have hard starting issues after driving and then leave it parted for a week or so. I started it the other day for about 2 minutes and shut it off. After a week there is still fuel in the line. Sao I think I have a boiling issue after driving and I am not sure how to address this issue.
JA: When did you last fill the tank? And do you smell gasoline around the engine?
Customer: I filled the tank about 2 weeks ago and there is no gas smell around the engine.
JA: Are you fixing your F150 yourself? What have you tried so far?
Customer: Yes I am doing it myself. I have replaced the fuel pump, put in a check valve between the fuel pump and carb and installed a clear fuel filter ( so I could see fuel in line or not).
JA: Anything else you want the mechanic to know before I connect you?
Customer: no

hello, my name is ***** ***** I will be glad to assist you. please allow me a couple of minutes to gather some basic info.


it sounds like the carb is leaking down internally when sitting. you have to prime and fill the carb before it will start.

when this happens, take off the air filter and push the throttle and see if you see fuel come out the passage for the accelerator pump.


Customer: replied 1 month ago.
I started and ran the truck for about 2 minutes a week ago then turned it off before it got to temp. A week later I checked and The fuel line still has fuel in it and the truck started right up. It seems to only be an issue when the run has run up to operating temp.

then it may be vapor lock from low fuel pressure. check the fuel pump pressure. it should be around 7 lbs


Customer: replied 1 month ago.
The fuel pump was replaced about 3 months ago.

still need to check it to be sure it is not bad.

Customer: replied 1 month ago.
OK, but this issue has been going on a while and the new fuel pump had no effect on it.

ok, but the pressure can be effected by hoses between the tank and the pump. low pressure will indicate that.

you still need to check for fuel in the carb as well.


Customer: replied 1 month ago.
OK, Thank You Much.

your welcome

PLease take a moment and rate my service 3 stars or better. that will allow the site to pay me for my efforts.


roy and 5 other Ford Specialists are ready to help you
Customer: replied 1 month ago.

thank you