Truck will start but will idle down and die


Asked by Jan 16, 2016 at 05:57 PM about the 1975 Ford F-100

Question type: Maintenance & Repair

I have a 1975 F100 Ranger XLT Supercab.  It has a 302 with 2 barrel carburetor on it.  I just rebuilt the carb and replaced the mechanical fuel pump and bypassed the electric fuel pump some guy had on it.  Fuel filter is clean.  I can turn it over no problem, but it will run for about 3 seconds and will idle down and die.  If I hit the gas pedal it will run but will again try to die when I let off.  I can not see any vacuum leaks.  Any ideas?

4 Answers


Spray a can of carburetor cleaner into carb not only cleans carburetor but also intake and cylinders and cleans valves. Also check air filter and replace if necessary.


Sounds like the carb isn't setup correctly. Try adjust the air screws in the carb base, I have usually started by turning them all the way in then backing out 2.5 turns as a starting point. HTH


A week ago I had it running perfectly. I could start it and run it for twenty minutes no problem. Then I put a bunch of gas in the gas tanks and tried running it and that was when this problem started. So I bypassed the electric fuel pump, replaced the mechanical pump and have clean brand new gas feeding directly from a clean brand new gas can into the mechanical fuel pump. That didn't help for long. After it started acting up again, I adjusted the idle control screw because I thought it might be idling too low but that didn't help either.


Found a problem. The brand new fuel filter leaks like a sieve. Otherwise it ran fine when I was working on it yesterday, until I tried to put it in reverse. But gave it a little gas and it went just fine. Thanks for the help!

Your Answer

Add photo

Related Questions

  • f100 stalls in gear 15 answers

    i have an 82 f100 4.9 300 she has vacuum leaks but in idle runs great timing was set to 10 degrees and carb was rebuilt and cleaned by a local carb shop but the truck itself has trouble starting runs ...

    1982 Ford F-100


    Maintenance & Repair

  • truck runs for fifteen minutes then dies and won't start for at least twenty minutes. I think I have pulled my hair and teeth out trying to figure this out!! 31 answers

    73 f100390 c.i; Replaced timing chain,distributor,plugs, new cap, pertronix ignitor, fuel filter, gas tank, Compression is 120 7 cylinders 140 on 1. Checked and adjusted floats and cleaned, carburator...

    1973 Ford F-100


    Maintenance & Repair

  • 1982 F100 barely idles but revs and goes down then revs and goes down 7 answers

    1982 F100 barely idles but revs and goes down then revs and goes down. The advice months ago about the gummed choke and needle worked. I have been getting the boys to keep the carb clean and choke uns...

    Ford F-100


    Maintenance & Repair

  • Carburetor Help!!!! 5 answers

    I have a 67 Ford f100 with a 352 and i just put a rebuilt carb on with 300 miles on it, and it sounds like the carb isnt getting enough fuel to get out of first gear. carb sounds like air blowing ou...

    1967 Ford F-100 Ranger


    Maintenance & Repair

  • Start but die when it get warm . 5 answers

    My truck is a 1992 F150 with the 5.0,it run find when i start it but after about 10 min. it die and you have to hold the foot paddle down to the floor to start,but then it is flooded,any help would ...

    1992 Ford F-150 STD Stepside SB


    Maintenance & Repair


Looking for a Used F-100 in your area?

CarGurus has 149 nationwide F-100 listings and the tools to find you a great deal.


Search Ford F-100 Questions

Ford F-100 Experts

#1 tennisshoes
Reputation 440
#2 MrBlueOval
Reputation 300
#3 Rowefast
Reputation 280
View All

Related Models For Sale

Used Ford F-150
2,179 Great Deals out of 206,277 listings starting at $1,499
Used Ford F-250
479 listings starting at $3,475
Used Ford Mustang
458 Great Deals out of 45,641 listings starting at $1,999
Used Ford Bronco
192 listings
Used Chevrolet Corvette
121 Great Deals out of 20,599 listings starting at $3,000

Used Cars For Sale

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.