For clarification,
1991 Ford F-150 XLT Lariat5.0L V8Automatic Transmission
We just swapped out some of the filters recently (Fuel, Air, Crankshaft Blowback under the air filter)
And the battery cables because our original ground cable was broken at the connector.

Since the switch of all these parts, it's been chugging harder than usual and even Sputtering and stalling out when coming to a stop. Today was the worst day because it did it twice, once it started right back up, the second time I needed to get a jump start and give it a little extra gas.

It's also got this little issue where it'll smell like gasoline heavily out of the exhaust pipe, and it revs higher when you first start it up for the day (Apparently it's been a thing since the truck was purchased off the lot. We are the second owners of the vehicle)

We're pretty sure it MIGHT be either a fuel pressure issue with the new filter (it's a duralast inline filter against the frame) or maybe the Alternator finally giving up, but if that were true then it wouldn't have made it home in a single trip without another jump start.

Would love to hear some further examples, and I'll try to return your further specification requests as soon as possible.

 

Sounds like really rich issue. Any codes?

 

None right now. We just replaced the Throttle Position Sensor and another cable. It's running slightly better but still chugging and having issues with keeping itself running.

 

sounds like an upset, or bad sensor.

 

I guess it's just about finding the right sensor then? Only one we know for sure is going bad, is the front tank fuel level sensor.
Have any recommendations where to start looking?

 

with no codes, sadly no sir

 

if it's running rich, then a fuel pressure issue is unlikely, but its still easy to hook u a gauge and see what it's reading. the fact that it needed to be jump started means that something caused the battery to either die, or there is a poor connection at one of the posts. It is normal to have a higher revving idle on a cold start. And if you pull one of the spark plugs and inspect it, you can get a better idea of how the engine in running. If it is running too rich, the plugs could have fouled out. And does it run any differently with the IAC unplugged?

 

I would check if you accidentally knocked off a vacuum line.

 

You should put ALL the truck's details & history (as much as you know) into your signature so it shows with each post, as this page explains:

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Phone apps don't always show signatures, so you may need to switch to a real browser in desktop mode on your phone, or just use a desktop/laptop computer. Put your location (nearest city) in your profile & upload an avatar of the truck. The more pics you post of the truck, engine, wiring, labels, & undercarriage, the more likely we can help you. Not all its details are relevant to these issues, but you don't necessarily know which ones are relevant, so just put everything in now.

 

I have the same model truck, and am experiencing the same issue. Bought from a friend and it's seen better years but been good for the most part. Rear pump wasn't testable, front pump tested weak pressure so I replaced both pumps, fuel filter, and filler tubes (someone had vandalized them cutting through and stolen the fuel from the tanks...) and it's still doing it. I've got a temp sensor which will be put in hopefully this weekend, but am at kind of a loss.

As long as I can get it to catch and not let it die that first time, I can usually just rev through the chugging then I can start driving without issues after a few minutes of keeping the engine above 2000 rpms or so. If I let it die that first time, I might have to let it sit for 15 or 30 minutes before I can do anything. Pressing the accelerator does seem to help; which I had thought would have gone away now that pumps are both replaced and running.