1988 ford f150 4.9 300 misses on occasion

Asked by Dec 15, 2013 at 08:56 PM about the 1988 Ford F-150 XL Standard Cab LB

Question type: Maintenance & Repair

its slow to start at times. misses when the temp is rising to the normal temp when driving
at 55 for a while as soon as i let off the gas it clunks and i can smell fuel. i put a new
tank/sending unit fuel filter. also new plugs wires and ignition coil cap rotor i took it in to
get the fuel injectors professionally cleaned just cant figure it out

1 Answer

25,315

Usually, the Exhaust Manifold warps and takes the intake manifold with it causing a vacuum leak. Since it's fuel injected, there's no chance of the old "rich-in-the-center" cylinders. At least once a year, you should check the torque on the exhaust/intake manifold bolts. The same fasteners hold both of them on to the side of the engine. The weight of the 2 manifolds hanging off the side of the engine, and the expansion and contraction of a nice cool intake manifold and very hot exhaust manifold cause the gaskets to fail. There's a couple of ways to fix it: Replace the Intake/Exhaust gasket and have the two manifolds milled together for a flush fit and replace all of the fasteners OR go aftermarket (if you can still find them) and get separate manifolds - preferably with a Stainless Steel Exhaust manifold or Header.

1 of 1 people found this helpful.

Your Answer

Ford F-150 Experts

  • #1
    OJ
    Reputation
    8,760
  • #2
    dandyoun
    Reputation
    4,480
  • #3
    tennisshoes
    Reputation
    3,010
View All

Related Models For Sale

Used GMC Sierra 1500
799 Great Deals out of 67,592 listings starting at $1,350
Used Ford F-250
467 listings starting at $3,490
Used Ford Mustang
765 Great Deals out of 42,132 listings starting at $1,300

Used Cars For Sale

2018 Ford F-150 For Sale
7,091 listings starting at $18,539
2017 Ford F-150 For Sale
67 Great Deals out of 106,546 listings starting at $15,407
2016 Ford F-150 For Sale
117 Great Deals out of 7,732 listings starting at $18,990
2015 Ford F-150 For Sale
269 Great Deals out of 9,926 listings starting at $15,890
2014 Ford F-150 For Sale
360 Great Deals out of 13,097 listings starting at $8,990

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.