i changed the TPS and the O2 sensor. still doing it. also sucks air like a rocket engine when it starts to bounce the rpms. The rpms go between roughly 330-1000rpms when this happens. It all started about 5 days ago and is getting worse. started dropping till it shut itself off yesterday, when pulling out from a red light. ran full fuel system cleaner and gas treatment through it as well. IF/WHEN i can get it above 55mph, it runs perfectly fine. plz anyone?! my next step atm is buying a fuel pump.. also when it does this this, if i shut it off, it starts right back like nothing is wrong...for about 30secs...rinse and repeat.. i also cleaned the crap out of the TPS, with the appropriate cleaner.

 

Whoh - slowly step away from the parts cannon!

You need to check your fuel pressure before doing an expensive and time consuming fuel pump replacement.

You should probably also check for vacuum leaks and clean your throttle body and IAC before you start replacing any parts.

It would also be helpful if you mentioned the year, engine, etc.

 

Thank you! lol I have a 1998 XJ 4WD with the amazing 4.0...and it has 202,000miles on it. well i rechecked my fuses and one was blown. I'm a DA. lmao i changed it and just drove it to the store and back...seems fine now. it was fuse #20 in the box by the battery. After i posted this, i read another member who suggested that particular fuse to another person having a similar problem. he said it was to the heater for the ignition (i believe). if it blows again, any idea, what might be the culprit?

 

Heater to the ignition? I'd double check what exactly that fuse covers.

If it blows continuously then there's something wrong in the circuit - either a wire that's rubbed the casing off and is grounding out (or has come out of place) or a component failure drawing too much power. So check the FSM for 98 and see what that fuse circuit contains and then you can investigate the specific wires and components if it fails again.

 

And a general intake clean might not be bad due diligence overall if you haven't done it in a while.

Whatever you do, DO NOT use brake kleen on your MAF! Ask me how I know…
Use the dedicated MAF cleaner.

The IAC valve is good to clean, too—in fact, I'd up the ante and use carb cleaner and a toothbrush. Wear gloves…