Sometimes is runs good other times it cough and sputters in gear

VICKI67401

MEMBER
1998 FORD F-150
4.6L
2WD
349,000 MILES

Sometimes a smooth start, other times it cranks for a bit and then starts. After start sometimes runs fine, other times it cough and sputters in gear, almost shutting off. Step on the gas and sometimes coughs, sputters, and shuts off, other times it runs great. Have replaced; MAF, fuel pump, fuel filter, plugs and wires, previous owner took catalytic converters out. Am at a loss and very frustrated. Please help! Thanks in advance!

Friday, July 20th, 2018 AT 4:38 PM

1 Reply

PATENTED_REPAIR_PRO

MECHANIC
1,853 POSTS

During the times when the engine just cranks and no start, do you recall the fuel pump priming for a few seconds after you first turned the key to start?
If not, can you do that know and let me know if the engine starts or not, and the next time you get a crank and no start, listen if the fuel pump runs for two seconds.
My very first response was going to be a loose electrical connection in a harness or loose/poor ground. If the engine starts and runs fine now, perhaps wiggling some fuel and ignition/computer wire harnesses around listening if the engine stumbles or stalls at idle. If so, see if something is loose.

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Friday, July 20th, 2018 AT 5:45 PM