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

23,835

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 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

Search Ford F-150 Questions

Ford F-150 Experts

#1 OJ
OJ
Reputation 7,700
#2 dandyoun
dandyoun
Reputation 4,330
#3 tennisshoes
tennisshoes
Reputation 2,690
View All

Related Models For Sale

Used GMC Sierra 1500
799 Great Deals out of 67,169 listings starting at $2,700
Used Ford Mustang
388 Great Deals out of 47,511 listings starting at $1,800
Used Ford F-250
464 listings starting at $3,975
Used Ford Ranger
186 Great Deals out of 6,019 listings starting at $1,750
Used Jeep Wrangler
275 Great Deals out of 18,613 listings starting at $2,995

Used Cars For Sale

2017 Ford F-150 For Sale
21 Great Deals out of 126,273 listings starting at $16,464
2016 Ford F-150 For Sale
117 Great Deals out of 21,594 listings starting at $18,897
2015 Ford F-150 For Sale
191 Great Deals out of 7,578 listings starting at $10,999
2014 Ford F-150 For Sale
381 Great Deals out of 12,548 listings starting at $7,995