OK, sheet, when you first start it up ur usually fine, but after a while it will lose power and then as you accelerate the car will suddenly act as though you took your foot off the gas. Sometimes just stabbing the throttle ends it. Sometimes it continues bucking, sometimes making power then immediately falling on its face. If you pull it outta gear, turn it off, turn it back on, it'll run great for about 30 seconds before potentially repeating the whole spiel. It doesn't stall.

Initially it sat through a cold spell, and the problem started. We used some heet and ran the tank low, replaced the filter and filled her up, ran great for 3 days. Then back at it.

Since the weather has been warmer the last couple days it has run just fine!

Thought it was water in the fuel, then a filter issue, then a pressure issue but a friend says it sounds like tps but no code. What are the symptoms of some likely issues? Let's talk about this a bit and get things figured out!!

 

Changed the filter again during a particularly bad spell in a rainy parking lot, did nothing this time.

 

how old is the cat?

 

Ancient. 800$ Isuzu 4x4.... I've been focusing on fuel vs ignition problems being that it decelerates so smoothly almost like its not firing, or told that the throttle is being applied. -momentarily

At other times it'll just seem down on power, and you know its about to act up.

Then cycling it off/on clears it right up. Ignition module? Clogged filter sock?

 

It occasionally feels kinda soft like its leaning out. So that's making me think its fuel

 

Third day straight above 50 and its running great.. Chime in any time....

 

Since the problem started after it was parked for a while, that always makes the fuel system the leading suspect IMO.
I'd suggest checking the fuel pressure. If you can, try to rig it up so you'll be able to watch the gauge when it's misfiring.

 

Well its been almost a week w flawless operation, it even did a day delivering flowers... So no issue to monitor.

Classic fuel pump?

 

Maybe you got a tank full of bad gas. Your best bet is to drive it with a fuel pressure tester taped to the windshield.

 

Yeah, waiting on that TBI adapter....

 

Its been through lots of gas though, contaminated fuel was first thought.... (Because I'm lazy)

 

What could be the significance of cycling the ignition solving the problem temporarily, 100% OF THE TIME?!!

Oh, its back to running like crap